Context
Psychotropic medication polypharmacy is common in psychiatric outpatient settings and, in some patient groups, may have increased in recent years.
Objective
To examine patterns and recent trends in psychotropic polypharmacy among visits to office-based psychiatrists.
Design
Annual data from the 1996-2006 cross-sectional National Ambulatory Medical Care Surveys were analyzed to examine patterns and trends in psychotropic polypharmacy within nationally representative samples of 13 079 visits to office-based psychiatrists.
Setting
Office-based psychiatry practices in the United States.
Participants
Outpatients with mental disorder diagnoses visiting office-based psychiatrists.
Main Outcome Measure
Number of medications prescribed in each visit and specific medication combinations.
Results
There was an increase in the number of psychotropic medications prescribed across years; visits with 2 or more medications increased from 42.6% in 1996-1997 to 59.8% in 2005-2006; visits with 3 or more medications increased from 16.9% to 33.2% (both P < .001). The median number of medications prescribed in each visit increased from 1 in 1996-1997 to 2 in 2005-2006 (mean increase: 40.1%). The increasing trend of psychotropic polypharmacy was mostly similar across visits by different patient groups and persisted after controlling for background characteristics. Prescription for 2 or more antidepressants, antipsychotics, sedative-hypnotics, and antidepressant-antipsychotic combinations, but not other combinations, significantly increased across survey years. There was no increase in prescription of mood stabilizer combinations. In multivariate analyses, the odds of receiving 2 or more antidepressants were significantly associated with a diagnosis of major depression (odds ratio [OR], 3.44; 99% confidence interval [CI], 2.58-4.58); 2 or more antipsychotics, with schizophrenia (OR, 6.75; 99% CI, 3.52-12.92); 2 or more mood stabilizers, with bipolar disorder (OR, 15.46; 99% CI, 6.77-35.31); and 2 or more sedative-hypnotics, with anxiety disorders (OR, 2.13; 99% CI, 1.41-3.22).
Conclusions
There has been a recent significant increase in polypharmacy involving antidepressant and antipsychotic medications. While some of these combinations are supported by clinical trials, many are of unproven efficacy. These trends put patients at increased risk of drug-drug interactions with uncertain gains for quality of care and clinical outcomes.
In many clinical situations, use of more than 1 psychotropic medication from the same or a different class is indicated.1,2 Depressed adults, for example, who partially respond to citalopram hydrobromide alone, significantly improve following addition of a second antidepressant (bupropion hydrochloride).3 Addition of antipsychotics to mood stabilizers for acute mania,4 short-term use of benzodiazepines in the early treatment course of major depression with antidepressants,5 and addition of antipsychotics to antidepressants for major depression with psychotic features6 represent other examples of empirically supported psychotropic polypharmacy.
In routine psychiatric practice, however, patients often receive psychiatric medication combinations that are not well supported by controlled clinical trials.7-16 One increasingly common combination is treatment with 2 concurrent antipsychotic medications.8,9,11,16-21 Support for this practice is largely confined to case reports and open-label trials11,17 rather than double-blind trials.18 In 1 analysis of data from Medicaid enrollees diagnosed with schizophrenia, there was a 4-fold increase from 3.3% to 13.7% in the percentage of patients receiving antipsychotic polypharmacy between 1999 and 2005.9 Psychotropic polypharmacy is also common in mood disorders.22-25 In a study of patients with treatment-refractory mood disorders discharged from the US National Institute of Mental Health Biological Psychiatry Branch, the percentage taking 3 or more medications increased from 3.3% in 1974-1979 to 43.8% in 1990-1995.22
Much remains to be learned regarding patterns of psychotropic polypharmacy in routine psychiatric practice. It is not known, for example, which combinations are most common in community practice, whether the likelihood of receiving these medication combinations has changed in recent years, and which patients are most likely to receive these medication combinations. Delineating within- and across-class psychotropic polypharmacy trends may inform evaluations of risk of adverse effects and drug-drug interactions19,26,27 and sources of the increasing share of mental health expenditures accounted for by medications.12,21,25,28,29 Identification of these emerging trends may also suggest candidate patient populations and medication combinations for clinical trials of drug efficacy and safety or for comparative effectiveness studies in real-world populations.30
This report examines recent trends in psychotropic polypharmacy in a large and representative sample of visits to US office-based psychiatrists between the mid-1990s and mid-2000s. We explore trends in within- and between-class psychotropic polypharmacy focusing on some of the most common combinations of psychotropic medications in outpatient psychiatric practice. We further examine patterns of psychotropic polypharmacy according to patient sociodemographic and clinical characteristics. The analysis is limited to visits to psychiatrists because psychiatrists tend to treat the most severely ill mental health patients and have the most extensive training and experience prescribing psychotropic medications.31-33 To our knowledge, this is the first study to examine trends in psychotropic polypharmacy involving major medication classes in a nationally representative sample of visits to office-based psychiatrists.
Data were drawn from 11 consecutive years of the National Ambulatory Medical Care Survey (NAMCS) from 1996 to 2006.34,35 NAMCS is a multistage probability survey of visits to office-based physicians. The survey response rate varied from 58.9% to 70.4% (median = 66.9%). A systematic random sample of visits to each physician was drawn during a randomly selected 1-week period (n = 284 638 visits).34 We further limited the sample to 13 079 visits to psychiatrists by adults (18 years or older) in which the patient actually saw the physician and was given a mental disorder diagnosis (International Classification of Diseases, Ninth Revision, Clinical Modification codes 290-319).
For each visit, the physician or a member of the physician's staff provided information about patient sociodemographic and clinical characteristics as well as psychotropic medications prescribed, supplied, or administered at the visit.
Psychotropic medications were ascertained based on generic names. Up to 6 medications were recorded in each visit in NAMCS 1996-2002. Starting from 2003, the maximum number of medications recorded was increased to 8. To make the years comparable for this study, we limited the maximum number of medications to 6 in all years. We focused on the 4 major classes of psychotropic medications for adults: antidepressants, antipsychotics, mood stabilizers, and sedative-hypnotics. Antidepressants included amitriptyline hydrochloride, amoxapine, bupropion, citalopram, clomipramine hydrochloride, desipramine hydrochloride, doxepin hydrochloride, duloxetine hydrochloride, escitalopram oxalate, fluoxetine, fluvoxamine, imipramine, isocarboxazid, maprotiline, mirtazapine, nefazodone hydrochloride, nortriptyline hydrochloride, paroxetine hydrochloride, phenelzine sulfate, protriptyline hydrochloride, sertraline hydrochloride, tranylcypromine sulfate, trazodone hydrochloride, trimipramine, and venlafaxine hydrochloride. Antipsychotics included aripiprazole, chlorpromazine hydrochloride, clozapine, fluphenazine, haloperidol, loxapine, mesoridazine, molindone hydrochloride, olanzapine, perphenazine, pimozide, quetiapine fumarate, risperidone, thioridazine, thiothixene, trifluperazine hydrochloride, and ziprasidone hydrochloride. Mood stabilizers included carbamazepine, lamotrigine, lithium, and valproate sodium/divalproex sodium. Sedative-hypnotics included alprazolam, butabarbital, chlordiazepoxide, chloral hydrate, chlorazepate, clonazepam, diazepam, diphenhydramine, eszopiclone, estazolam, flurazepam hydrochloride, hydroxyzine, lorazepam, meprobamate, nitrazepam, oxazepam, phenobarbital, secobarbital, temazepam, triazolam, zaleplon, and zolpidem tartrate.
We also assessed other psychotropic medications for calculation of the total number of prescribed medications. These included acamprosate calcium, amphetamine, atenolol, atomoxetine hydrochloride, benztropine mesylate, buprenorphine hydrochloride, buspirone hydrochloride, clonidine hydrochloride, dexmethylphenidate hydrochloride, dextroamphetamine, disulfiram, donepezil hydrochloride, gabapentin, galantamine hydrobromide, guanfacine hydrochloride, methadone hydrochloride, methylphenidate hydrochloride, metoprolol, modafinil, nadolol, naltrexone hydrochloride, naloxone hydrochloride, oxcarbazepine, pemoline, pregabalin, propranolol, rivastigmine tartrate, topiramate, and trihexyphenidyl hydrochloride.
We counted anticonvulsants (carbamazepine, lamotrigine, oxcarbazepine, topiramate, valproate/divalproex, phenobarbital, gabapentin, and pregabalin) among psychotropic medications only if the patient did not have an additional seizure disorder diagnosis. Also, we counted guanfacine, clonidine, and β-blockers (atenolol, metoprolol, nadolol, and propranolol) among psychotropic medications only if the patient did not have an additional diagnosis of hypertension. Finally, selegiline, benztropine, and trihexyphenidyl were counted among psychotropic medications only if the patient did not have an additional diagnosis of Parkinson disease.
Mental disorder diagnosis was recorded based on International Classification of Diseases, Ninth Revision, Clinical Modification codes. Up to 3 diagnoses were recorded for each visit. These diagnoses were given in 96.0% of all visits to psychiatrists during the study period. Specific diagnoses included major depression (codes 296.2 and 296.3), dysthymia (code 300.4), bipolar disorder (codes 296.0-296.1 and 296.4-296.8), other affective disorders (codes 296.9 and 311.0), generalized anxiety disorder (code 300.02), panic disorder with or without agoraphobia (codes 300.01 and 300.21), obsessive-compulsive disorder (code 300.3), posttraumatic stress disorder (code 309.81), social phobia (code 300.23), schizophrenia (code 295), and personality disorders (code 301). Because of the small number of sampled patient visits with each anxiety disorder, we combined these disorders into an “anxiety disorders” category. For the same reason, we combined dysthymia and other affective disorders. In addition, the total number of psychiatric diagnoses in each visit were dichotomized into 1 diagnosis vs more than 1 diagnosis.
Primary source of payment was classified as private insurance, Medicaid, Medicare, self-pay, or “other types.”
Other variables used in the multivariate analyses included patient's age, sex, race/ethnicity (white, minority), office setting (freestanding private solo practice, freestanding private group practice, other settings), visit order (established vs first-time or new patient), and region of the country (Northeast, South, West, Southwest).
Analyses were conducted in 2 stages. In the first stage, we examined time trends in the number of psychotropic medications prescribed using bivariate and multivariate binary logistic models. Survey year was transformed by subtracting 1996 from the year and dividing the results by 10. Thus, the transformed value was 0 for 1996 and 1 for 2006. The odds ratios (ORs) associated with this transformed variable of survey year represent a change in odds of psychotropic polypharmacy during the entire study period (ie, 1996-2006).
The multivariate model adjusted for and examined the effects of age, sex, race/ethnicity, psychiatric diagnosis, number of psychiatric diagnoses, insurance, visit order, office setting, and region. To assess variation in associations of patient and visit characteristics across years, interaction terms with survey year were introduced into the model and tested one by one. Significant interaction terms suggest variations in time trends across groups.
In the second stage, these bivariate and multivariate analyses were repeated for each specific combination of the 4 medication classes. The same variables described earlier were entered into the multivariate models.
Analyses were conducted using the Stata 10 software.36 All analyses were adjusted for visit weights, clustering, and stratification of data using design elements provided by the National Center for Health Statistics. When adjusted for these design elements, NAMCS data represent annual visits to office-based physicians in the United States.34,35 Because of the large sample size, a P value of <.01 was used to assess statistical significance.
Between 1996-1997 and 2005-2006, the percentage of visits in which any psychotropic medications were prescribed increased from 73.1% to 86.2% (OR, 2.40; 99% confidence interval [CI], 1.36-4.24; P < .001). Similarly, the percentage of visits with 2 or more psychotropic medications increased from 42.6% to 59.8% (OR, 2.10; 99% CI, 1.41-3.15; P < .001) and those with 3 or more psychotropic medications increased from 16.9% to 33.2% (OR, 2.60; 99% CI, 1.61-4.22; P < .001) (Figure). The median number of medications prescribed per visit doubled from 1 in 1996-1997 to 2 in 2005-2006. The mean number increased by 40.1% from 1.42 in 1996-1997 to 1.99 in 2005-2006.
The time trend persisted in a multivariate model adjusting for demographic and clinical characteristics of visits Table 1). Furthermore, the time trend was similar across most demographic and clinical characteristics as indicated by the statistically nonsignificant tests for all interaction terms except for the anxiety disorders (F1,601 = 6.95; P = .009). The percentage of visits in which 2 or more psychotropic medications were prescribed increased more slowly among visits with an anxiety disorder diagnosis (52.8% in 1996-1997 to 61.2% in 2005-2006) than among visits with other diagnoses (40.7% to 59.4%, respectively).
Visits were more likely to involve prescription of 2 or more psychotropic medications if they were made by patients aged 45 to 64 years compared with patients aged 18 to 44 years; patients with major depression, bipolar disorder, anxiety disorders, or schizophrenia compared with other diagnoses; patients with comorbid disorders compared with those with a single diagnosis; and those covered by public or “other” types of insurance compared with private insurance. In contrast, visits were less likely to involve 2 or more medications if they were made by men compared with women, self-paying patients compared with those covered by private insurance, and new patients compared with returning patients (Table 1).
Analyses of specific medication combinations
The top section of Table 2 presents numbers and percentages of visits to psychiatrists in which each major medication class and combination were prescribed. During the study period, antidepressants (61.7%) were the most commonly prescribed class of medications followed by sedative-hypnotics (31.5%), antipsychotics (22.4%), and mood stabilizers (12.4%). Combinations of antidepressants with sedative-hypnotics (23.1%), antipsychotics (12.9%), and other antidepressants (12.6%) were the first, second, and third most commonly prescribed psychotropic medication combinations overall and maintained these relative rankings across survey years (Table 2, middle section).
Over time, the percentages of visits in which combinations of antidepressants and antipsychotics or combinations of 2 or more antipsychotics or 2 or more antidepressants were prescribed significantly increased (Table 2, middle and lower sections). In contrast, combinations of mood stabilizers and sedative-hypnotics with each other and with other medication groups did not appreciably change (Table 2, middle and lower sections).
Multivariate analyses of within–psychotropic medication class combinations
The results of multivariate analyses of within–psychotropic medication class combinations were generally consistent with the bivariate analyses (Table 3). The time trend for 2 or more sedative-hypnotics, which was not statistically significant in bivariate analyses, became significant in the multivariate model (Table 3).
Specific psychotropic medication combinations were significantly more commonly prescribed for some patient groups than others (Table 3). Combinations of 2 or more antidepressants, for example, were significantly more common in visits by patients aged 45 to 64 years compared with visits by patients aged 18 to 44 years, women compared with men, and patients with mood and anxiety disorders compared with other diagnoses (Table 3).
A combination of 2 or more antipsychotics was significantly more common in visits with a diagnosis of schizophrenia compared with other diagnoses and in visits paid for with public compared with private insurance (Table 3). This medication combination was less common in visits with a diagnosis of other depressive disorders. The interaction term for diagnosis of major depression with survey year was statistically significant (F1,601 = 11.43; P < .001). Over time, the prevalence of visits with 2 or more antipsychotics modestly decreased in the treatment of major depression (1.5% in 1996-1997 to 0.9% in 2005-2006), whereas this combination became more common in visits with other diagnoses (1.2% to 5.6%, respectively).
The prevalence of visits with 2 or more mood stabilizers did not change across survey years. However, such visits were many times more common in the treatment of bipolar disorder compared with other diagnoses (5.9% in 1996-1997 vs 0.3% in 2005-2006) (Table 3).
Two or more sedative-hypnotics were more commonly prescribed in visits by women than by men, visits with a diagnosis of anxiety disorder than other diagnoses, visits with more than 1 psychiatric diagnosis than those with 1 diagnosis, and visits covered by Medicare than other payers. Furthermore, interaction terms of survey year with the 65 years and older age group, diagnosis of schizophrenia, and Medicare insurance coverage were statistically significant, indicating that time trends were significantly different across these groups. Over time, multiple sedative-hypnotics became more commonly prescribed in visits by patients younger than 65 years (3.2% to 7.9%), though less common in visits by older patients (7.4% to 2.5%) (F1,601 = 15.05; P < .001). This medication combination also became more common in visits by patients with diagnoses other than schizophrenia (3.1% to 7.6%), but less common in visits by patients with schizophrenia (9.6% to 0.5%) (F1,601 = 7.89; P = .005). The combination of 2 or more sedative-hypnotics also became less commonly prescribed in Medicare-insured visits (7.3% in 1996-1997 to 6.6% in 2005-2006), but more common in visits covered by other payers (3.3% to 7.4%) (F1,601 = 7.36; P = .007) (Table 3).
Multivariate analyses of between–medication class combinations
The association of survey year with prescription of antidepressant-antipsychotic combinations persisted in multivariate analysis (Table 4). Antidepressant-antipsychotic combinations were also more commonly prescribed in visits by women than men; visits with diagnoses of major depression, bipolar disorder, and schizophrenia than other diagnoses; visits with more than 1 psychiatric diagnosis; and visits covered by public insurance or payment arrangements other than private insurance or self-pay, but less commonly in visits by the 65 years and older age group than younger patients (Table 4). Antidepressant–mood stabilizer combinations were more common in visits with a bipolar or schizophrenia diagnosis than those with other diagnoses and by new compared with returning patients (Table 4). Antidepressant and sedative-hypnotic combinations occurred disproportionately in visits by patients aged 45 to 64 years, visits with a diagnosis of major depression or anxiety disorder, and visits covered by Medicare. This combination was less commonly prescribed in visits by men, minorities, and self-paying patients (Table 4).
Antipsychotic–mood stabilizer combinations were significantly more common in visits with a bipolar disorder or schizophrenia diagnosis compared with other diagnoses. This combination was also more common in publicly insured visits and visits with “other” payment arrangements than in privately insured visits. By contrast, this combination was less commonly prescribed among visits by older patients compared with younger patients and among those with depressive disorders, anxiety disorders, and new patients as compared with returning patients (Table 5).
Antipsychotic and sedative-hypnotic combinations were significantly more common in visits by patients aged 45 to 64 years than the younger age group, visits with a diagnosis of bipolar disorder or schizophrenia, visits with more than 1 diagnosis, and visits with public insurance than other payment sources. This combination was less commonly prescribed for visits by older adults than younger adults, men than women, and new than returning patients (Table 5). Finally, mood stabilizer–sedative-hypnotic combinations were more commonly prescribed in visits by patients aged 45 to 64 years compared with younger adults and visits with a bipolar or schizophrenia diagnosis compared with other diagnoses (Table 5).
The results of this study should be interpreted in the context of several limitations. First, this is an observational study and although the multivariate analyses adjust for a number of patient and visit characteristics, the range of variables is limited and multivariate methods cannot rule out residual confounding due to unmeasured differences among patient groups across survey years. Thus, results should be interpreted with caution. Second, the analyses were limited to office-based psychiatric practices. The trends and patterns in psychotropic polypharmacy may not generalize to other treatment settings. However, psychotropic polypharmacy (ie, prescription of ≥2 psychotropic medications) also increased among outpatient visits to nonpsychiatrist physicians from 1.9% in 1996-1997 to 5% in 2005-2006 (OR, 3.02; 99% CI, 2.28-4.00; P < .001). Thus, psychotropic polypharmacy is not limited to psychiatric practices. Third, because of the cross-sectional survey design, it is not possible to determine previous clinical response to monotherapy regimens or the course of medication treatment or to measure the effects of trends in psychotropic polypharmacy on clinical outcomes. Fourth, NAMCS only records medications prescribed at each visit. For patients who receive care from several physicians, the survey may underestimate the number of psychotropic medications actually taken by individual patients.25 Fifth, despite the relatively large sample sizes, the limited number of visits within certain patient groups and specific medication combinations forced us to combine some patient groups (eg, anxiety disorders, racial/ethnic minorities). Furthermore, results for the less common medication combinations, such as combinations of 2 or more mood stabilizers, should be interpreted with caution. Sixth, diagnoses might not be exactly comparable across time. For example, patients given a diagnosis of bipolar disorder in 1996 might be somewhat different from those given this diagnosis in 2006. Without expert validation or structured interviews, it is not possible to examine these variations. Finally, because NAMCS records visits rather than patients, some patient duplication may have occurred during the 1-week sampling period.
Despite these limitations, this report represents the first national study of psychotropic polypharmacy trends in office-based psychiatric practice to our knowledge. Between 1996 and 2006, there was a substantial increase in the proportion of patient visits in which 2 or more psychotropic medications were prescribed. During this period, the proportion of visits in which 3 or more psychotropic medications were prescribed increased from fewer than 1 in 5 to nearly 1 in 3.
Significant time trends appeared to be mainly limited to concomitant prescription of 2 or more antidepressants or antipsychotics as well as combinations of antipsychotics and antidepressants. With the exception of combinations of 2 or more sedative-hypnotics, none of the other combinations involving mood stabilizers or sedative-hypnotics showed a significant increase across time in multivariate analysis. This finding is consistent with other reports indicating an increase in the use of antidepressant and antipsychotic medications in recent years.37-39
Much of the available literature on psychotropic polypharmacy has focused on antipsychotic polypharmacy.8,9,11,12,17,21,26,40,41 Frequently, antipsychotic polypharmacy represents an attempt by the physician to achieve a greater or a faster therapeutic response.11 Many patients in routine care settings continue to experience significant symptoms while following usual treatment regimens.42 In other cases, antipsychotic polypharmacy may be the result of “getting stuck” in switching from 1 antipsychotic medication to another.16,41 However, evidence supporting concomitant use of more than 1 antipsychotic medication is limited and this therapeutic option should be a last resort after all other options, including clozapine, have failed.43
While the evidence for added benefit of antipsychotic polypharmacy is limited, there is growing evidence regarding the increased adverse effects associated with such combinations. For example, a double-blind controlled study of risperidone added to clozapine in refractory schizophrenia found no evidence for improved outcome in the combined-treatment group compared with the clozapine-alone group but did find a significantly greater increase in fasting blood glucose level in the combined-treatment group.18 Similarly, a small study of combined olanzapine-risperidone therapy in patients with schizophrenia who had not responded to sequential monotherapy with olanzapine, quetiapine, and risperidone found a significant increase in body weight, prolactin level, and total cholesterol level after an average of 10 weeks of concomitant treatment.19 These data call for more careful monitoring of metabolic parameters in patients taking more than 1 antipsychotic medication. Concerns have been also voiced about increased risk of QT prolongation in concomitant use of ziprasidone with low-potency conventional antipsychotic medications (eg, thioridazine),44 as well as worsening of psychosis due to displacement of antipsychotic medications from the D2 receptor when aripiprazole is added as a concomitant treatment.44,45
The evidence for combining antidepressants from different classes is somewhat stronger than other medication combinations.3,46,47 However, this option also should be considered only after optimal monotherapy and switching to an antidepressant from a different class have failed.48 Furthermore, most available data on antidepressant combination therapy focus on patients with major depression. The merits of antidepressant combinations in treatment of other psychiatric conditions are unknown.
Antidepressant combinations also carry increased risks for adverse effects. The risks of serotonin syndrome and hypertensive crisis when combining monoamine oxidase inhibitors with other antidepressants are well known.44 In addition, some antidepressants inhibit cytochrome P450 enzymes and thus impact the metabolism of other psychotropic medications, including other antidepressants. Fluoxetine, sertraline, and paroxetine are potent inhibitors of cytochrome P450 2D6 and could potentially lead to marked elevations in concentration of desipramine and nortriptyline.49 Thus, coadministration of antidepressant medications calls for careful consideration of these drug-drug interactions and may require monitoring of serum levels of these medications. A further potential complication associated with overuse of antidepressant medications is the risk of emerging manic symptoms in susceptible depressed patients50,51 and acceleration of mood cycles in patients with bipolar disorder.52 However, it is not clear whether antidepressant polypharmacy is associated with additional risk of these outcomes.
The use of antidepressant-antipsychotic medication combinations in selected patient groups is also supported by some evidence.6 The fluoxetine-olanzapine combination for treatment of bipolar depression was one of the first psychotropic medication combinations to receive Food and Drug Administration approval for treatment of a mood disorder.53 Nevertheless, there are concerns about overprescription of antipsychotic medications in patients with major depression and overprescription of antidepressants in patients with schizophrenia.40,54 In an observational study of schizophrenic outpatients stabilized with antipsychotics and antidepressants, no change was noted over 3 months in Clinical Global Impressions–Improvement ratings in 82% of antidepressant tapers; improvement occurred in 14% of tapers; and worsening, in only 5%.40 In another study, discontinuation of conventional antipsychotic use in a small sample of patients with major depression led to significant improvement in clinical status.55 Furthermore, antidepressant-antipsychotic combinations are especially prone to adverse drug-drug interactions mainly because of the effects of antidepressants on the cytochrome P450 system.49 For example, both fluoxetine and fluvoxamine significantly increase the serum level of concomitantly used clozapine.56,57 Similar drug-drug interactions among other antidepressants and antipsychotics have also been reported.44,57,58 These interactions call for added caution when prescribing these medication combinations and, in some cases, careful monitoring of serum levels.
We found no increase across the survey years in the prevalence of visits in which 2 or more mood stabilizers or any combinations of mood stabilizers with other psychotropic medications were prescribed. The decline in the use of lithium—once the most commonly prescribed mood stabilizer—and the parallel growth in the use of antipsychotic medications as mood stabilizers in outpatient settings in recent years may be, at least partly, responsible for this finding.59 Between the years 1992-1995 and 1996-1999, the prevalence of psychiatric outpatient visits with a diagnosis of bipolar disorder in which lithium was prescribed decreased from 50.9% to 30.1%, while visits in which atypical antipsychotic medications were prescribed increased from 1.2% to 17.0%.59 While there is evidence supporting the efficacy of some antipsychotic medications in the treatment of acute manic episodes,60 the evidence regarding the efficacy of these medications in maintenance treatment of bipolar disorder is much less well developed.60,61 Furthermore, there are relatively few large head-to-head comparisons of antipsychotics and mood stabilizers for the treatment of bipolar disorder.62-65
The reasons for the recent increase in antidepressant and antipsychotic polypharmacy remain unclear. Changes in characteristics of patients, including increasing severity of illnesses, encountered in psychiatric practices and greater prevalence or recognition of psychiatric comorbidities offer possible explanations. Previous research suggests an association between severity of symptoms and antipsychotic polypharmacy.22,66,67 Furthermore, psychiatric comorbidities among outpatients are increasingly recognized,68 and an association between psychiatric comorbidities and psychotropic polypharmacy has been previously noted.69 We also found an association between comorbidities and prescription of antidepressant-antipsychotic combinations as well as antipsychotic–sedative-hypnotic combinations. However, time trends for antidepressant and antipsychotic polypharmacy remained significant even after adjusting for psychiatric diagnosis and comorbidity. Furthermore, we did not observe a significant change in the number of patients referred from general medical providers to psychiatrists—an indicator of greater clinical severity or complexity of disorders—over the study period (data not shown). Thus, there is little indication that changes in patient illness severity or comorbidity account for the observed trends in psychotropic polypharmacy.
A change in the style of psychiatric practice may have contributed to the increase in antidepressant-antipsychotic polypharmacy. Some psychiatrists may be placing greater emphasis on symptom reduction while lowering their concerns over the number of medications required to achieve this clinical goal.70 Another common practice is the off-label prescription of adjunctive atypical antipsychotic medications as sedatives.71 Growth in off-label prescription of antidepressant and antipsychotic medications has raised concerns.72,73 Consistent with this broad trend, most interaction terms of diagnosis with time were statistically nonsignificant, indicating that time trends for antidepressant and antipsychotic polypharmacy were similar across diagnostic groups.
In response to these concerns, there have been recent attempts to curtail psychotropic polypharmacy through quality improvement inititatives26 and physician training programs74 and by delineating explicit criteria for rational psychotropic polypharmacy regimens.1,2 Despite these efforts, the present analysis suggests that the rate of antidepressant and antipsychotic polypharmacy in outpatient psychiatric practice has increased in recent years. Continued unabated, the cost increases associated with increased use of these medications9,13,21 may bring on administrative mandates and restrictions in coverage to limit this practice. Because scant data exist to support the efficacy of some of the most common medication combinations, such as antipsychotic combinations or combinations of antidepressants and antipsychotics, prudence suggests that renewed clinical efforts should be made to limit the use of these combinations to clearly justifiable circumstances. At the same time, a new generation of research is needed to assess the efficacy, effectiveness, and safety of common concomitant medication regimens, especially in patients with multiple disorders or monotherapy-refractory conditions.
Submitted for Publication: December 2, 2008; final revision received May 8, 2009; accepted May 11, 2009.
Correspondence: Ramin Mojtabai, MD, PhD, MPH, Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, 624 N Broadway, Room 797, Baltimore, MD 21205 (rmojtaba@jhsph.edu).
Financial Disclosure: Dr Mojtabai reports receiving research support and an honorarium from Bristol-Myers Squibb. Dr Olfson reports receiving research support or honoraria from Pfizer, Eli Lilly, Bristol-Myers Squibb, AstraZeneca, and McNeil.
1.Ghaemi
SN Polypharmacy in Psychiatry. New York, NY: Dekker; 2002
2.Preskorn
SHLacey
RL Polypharmacy: when is it rational?
J Psychiatr Pract 2007;13
(2)
97- 105
PubMedGoogle Scholar 3.Trivedi
MHFava
MWisniewski
SRThase
MEQuitkin
FWarden
DRitz
LNierenberg
AALebowitz
BDBiggs
MMLuther
JFShores-Wilson
KRush
AJSTAR*D Study Team, Medication augmentation after the failure of SSRIs for depression.
N Engl J Med 2006;354
(12)
1243- 1252
PubMedGoogle Scholar 4.American Psychiatric Association, Practice guideline for the treatment of patients with bipolar disorder (revision).
Am J Psychiatry 2002;159
(4)
(suppl)1- 50
PubMedGoogle Scholar 5.American Psychiatric Association, Practice guideline for the treatment of patients with major depressive disorder (revision).
Am J Psychiatry 2000;157
(4)
(suppl)1- 45
PubMedGoogle Scholar 6.Wijkstra
JLijmer
JBalk
FGeddes
JNolen
WA Pharmacological treatment for psychotic depression.
Cochrane Database Syst Rev 2005;
(4)
CD004044
PubMedGoogle Scholar 7.Aparasu
RRMort
JRBrandt
H Polypharmacy trends in office visits by the elderly in the United States, 1990 and 2000.
Res Social Adm Pharm 2005;1
(3)
446- 459
PubMedGoogle Scholar 8.Botts
SHines
HLittrell
R Antipsychotic polypharmacy in the ambulatory care setting, 1993-2000.
Psychiatr Serv 2003;54
(8)
1086
PubMedGoogle Scholar 9.Gilmer
TPDolder
CRFolsom
DPMastin
WJeste
DV Antipsychotic polypharmacy trends among Medicaid beneficiaries with schizophrenia in San Diego County, 1999-2004.
Psychiatr Serv 2007;58
(7)
1007- 1010
PubMedGoogle Scholar 10.Haider
SIJohnell
KThorslund
MFastbom
J Trends in polypharmacy and potential drug-drug interactions across educational groups in elderly patients in Sweden for the period 1992-2002.
Int J Clin Pharmacol Ther 2007;45
(12)
643- 653
PubMedGoogle Scholar 11.Stahl
SMGrady
MM A critical review of atypical antipsychotic utilization: comparing monotherapy with polypharmacy and augmentation.
Curr Med Chem 2004;11
(3)
313- 327
PubMedGoogle Scholar 12.Valuck
RJMorrato
EHDodd
SOderda
GHaxby
DGAllen
RMedicaid Pharmacotherapy Research Consortium, How expensive is antipsychotic polypharmacy? experience from five US state Medicaid programs.
Curr Med Res Opin 2007;23
(10)
2567- 2576
PubMedGoogle Scholar 13.Zhu
BAscher-Svanum
HFaries
DECorrell
CUKane
JM Cost of antipsychotic polypharmacy in the treatment of schizophrenia.
BMC Psychiatry 2008;819
PubMedGoogle Scholar 14.West
JCWilk
JEOlfson
MRae
DSMarcus
SNarrow
WEPincus
HARegier
DA Patterns and quality of treatment for patients with schizophrenia in routine psychiatric practice.
Psychiatr Serv 2005;56
(3)
283- 291
PubMedGoogle Scholar 15.Karow
ALambert
M Polypharmacy in treatment with psychotropic drugs: an underestimated phenomenon.
Curr Opin Psychiatry 2003;16
(6)
713- 718
Google Scholar 16.Stahl
SM Antipsychotic polypharmacy, part 1: therapeutic option or dirty little secret?
J Clin Psychiatry 1999;60
(7)
425- 426
PubMedGoogle Scholar 17.Freudenreich
OGoff
DC Antipsychotic combination therapy in schizophrenia: a review of efficacy and risks of current combinations.
Acta Psychiatr Scand 2002;106
(5)
323- 330
PubMedGoogle Scholar 18.Honer
WGThornton
AEChen
EYChan
RCWong
JOBergmann
AFalkai
PPomarol-Clotet
E McKenna
PJStip
EWilliams
RMacEwan
GWWasan
KProcyshyn
RClozapine and Risperidone Enhancement (CARE) Study Group, Clozapine alone versus clozapine and risperidone with refractory schizophrenia.
N Engl J Med 2006;354
(5)
472- 482
PubMedGoogle Scholar 19.Suzuki
TUchida
HWatanabe
KNakajima
SNomura
KTakeuchi
HTanabe
AYagi
GKashima
H Effectiveness of antipsychotic polypharmacy for patients with treatment refractory schizophrenia: an open-label trial of olanzapine plus risperidone for those who failed to respond to a sequential treatment with olanzapine, quetiapine and risperidone.
Hum Psychopharmacol 2008;23
(6)
455- 463
PubMedGoogle Scholar 20.Tranulis
CSkalli
LLalonde
PNicole
LStip
E Benefits and risks of antipsychotic polypharmacy: an evidence-based review of the literature.
Drug Saf 2008;31
(1)
7- 20
PubMedGoogle Scholar 21.Clark
REBartels
SJMellman
TAPeacock
WJ Recent trends in antipsychotic combination therapy of schizophrenia and schizoaffective disorder: implications for state mental health policy.
Schizophr Bull 2002;28
(1)
75- 84
PubMedGoogle Scholar 22.Frye
MAKetter
TALeverich
GSHuggins
TLantz
CDenicoff
KDPost
RM The increasing use of polypharmacotherapy for refractory mood disorders: 22 years of study.
J Clin Psychiatry 2000;61
(1)
9- 15
PubMedGoogle Scholar 23. McIntyre
RSJerrell
JM Polypharmacy in children and adolescents treated for major depressive disorder: a claims database study.
J Clin Psychiatry 2009;70
(2)
240- 246
PubMedGoogle Scholar 24.Glezer
AByatt
NCook
R
JrRothschild
AJ Polypharmacy prevalence rates in the treatment of unipolar depression in an outpatient clinic.
J Affect Disord 2009;117
(1-2)
18- 23
PubMedGoogle Scholar 25.Kotzan
JAMaclean
RWade
WMartin
BCLami
HTadlock
GGottlieb
M Prevalence and patterns of concomitant use of selective serotonin reuptake inhibitors and other antidepressants in a high-cost polypharmacy cohort.
Clin Ther 2002;24
(2)
237- 248
PubMedGoogle Scholar 26.Gören
JLParks
JJGhinassi
FAMilton
CGOldham
JMHernandez
PChan
JHermann
RC When is antipsychotic polypharmacy supported by research evidence? implications for QI.
Jt Comm J Qual Patient Saf 2008;34
(10)
571- 582
PubMedGoogle Scholar 27.Urichuk
LPrior
TIDursun
SBaker
G Metabolism of atypical antipsychotics: involvement of cytochrome p450 enzymes and relevance for drug-drug interactions.
Curr Drug Metab 2008;9
(5)
410- 418
PubMedGoogle Scholar 28.Druss
BG Rising mental health costs: what are we getting for our money?
Health Aff (Millwood) 2006;25
(3)
614- 622
PubMedGoogle Scholar 29.Mark
TLLevit
KRBuck
JACoffey
RMVandivort-Warren
R Mental health treatment expenditure trends, 1986-2003.
Psychiatr Serv 2007;58
(8)
1041- 1048
PubMedGoogle Scholar 30.Slutsky
JRClancy
CM The Agency for Healthcare Research and Quality's Effective Health Care Program: creating a dynamic system for discovering and reporting what works in health care.
Am J Med Qual 2005;20
(6)
358- 360
PubMedGoogle Scholar 31.Mojtabai
ROlfson
M National patterns in antidepressant treatment by psychiatrists and general medical providers: results from the national comorbidity survey replication.
J Clin Psychiatry 2008;69
(7)
1064- 1074
PubMedGoogle Scholar 32.Olfson
MKlerman
GL Trends in the prescription of psychotropic medications: the role of physician specialty.
Med Care 1993;31
(6)
559- 564
PubMedGoogle Scholar 33.Mojtabai
R Datapoints: prescription patterns for mood and anxiety disorders in a community sample.
Psychiatr Serv 1999;50
(12)
1557
PubMedGoogle Scholar 34.Cherry
DKHing
EWoodwell
DARechtsteiner
EA National Ambulatory Medical Care Survey: 2006 summary.
Natl Health Stat Report 2008;
(3)
1- 39
PubMedGoogle Scholar 35.Woodwell
DA National Ambulatory Medical Care Survey: 1996 summary.
Adv Data 1997;
(295)
1- 25
PubMedGoogle Scholar 36. Stata Statistical Software [computer program]. Version 10. College Station, TX: StataCorp; 2008
37.Mojtabai
R Increase in antidepressant medication in the US adult population between 1990 and 2003.
Psychother Psychosom 2008;77
(2)
83- 92
PubMedGoogle Scholar 38.Depp
COjeda
VDMastin
WUnutzer
JGilmer
TP Trends in use of antipsychotics and mood stabilizers among Medicaid beneficiaries with bipolar disorder, 2001-2004.
Psychiatr Serv 2008;59
(10)
1169- 1174
PubMedGoogle Scholar 39.Aparasu
RRBhatara
VGupta
S US national trends in the use of antipsychotics during office visits, 1998-2002.
Ann Clin Psychiatry 2005;17
(3)
147- 152
PubMedGoogle Scholar 40.Glick
IDPham
DDavis
JM Concomitant medications may not improve outcome of antipsychotic monotherapy for stabilized patients with nonacute schizophrenia.
J Clin Psychiatry 2006;67
(8)
1261- 1265
PubMedGoogle Scholar 41.Tapp
AWood
AESecrest
LErdmann
JCubberley
LKilzieh
N Combination antipsychotic therapy in clinical practice.
Psychiatr Serv 2003;54
(1)
55- 59
PubMedGoogle Scholar 42.Young
ASNiv
NCohen
ANKessler
C McNagny
K The appropriateness of routine medication treatment for schizophrenia [published online November 7, 2008].
Schizophr BullPubMed
doi:10.1093/schbul/sbn138
Google Scholar 43.Miller
ALHall
CSBuchanan
RWBuckley
PFChiles
JAConley
RRCrismon
MLEreshefsky
LEssock
SMFinnerty
MMarder
SRMiller
DD McEvoy
JPRush
AJSaeed
SASchooler
NRShon
SPStroup
STarin-Godoy
B The Texas Medication Algorithm Project antipsychotic algorithm for schizophrenia: 2003 update.
J Clin Psychiatry 2004;65
(4)
500- 508
PubMedGoogle Scholar 44.Sandson
NBArmstrong
SCCozza
KLOesterheld
JR Drug-Drug Interaction Primer: A Compendium of Case Vignettes for the Practicing Clinician. Washington, DC: American Psychiatric Publishing; 2007
45.Adan-Manes
JGarcia-Parajua
P Aripiprazole in combination with other antipsychotic drugs may worsen psychosis.
J Clin Pharm Ther 2009;34
(2)
245- 246
PubMedGoogle Scholar 46.Shelton
RC The use of antidepressants in novel combination therapies.
J Clin Psychiatry 2003;64(suppl 2)14- 18
PubMedGoogle Scholar 47.Licht
RWQvitzau
S Treatment strategies in patients with major depression not responding to first-line sertraline treatment: a randomised study of extended duration of treatment, dose increase or mianserin augmentation.
Psychopharmacology (Berl) 2002;161
(2)
143- 151
PubMedGoogle Scholar 49.Nemeroff
CBDeVane
CLPollock
BG Newer antidepressants and the cytochrome P450 system.
Am J Psychiatry 1996;153
(3)
311- 320
PubMedGoogle Scholar 50.Akiskal
HSHantouche
EGAllilaire
JFSechter
DBourgeois
MLAzorin
JMChatenêt-Duchêne
LLancrenon
S Validating antidepressant-associated hypomania (bipolar III): a systematic comparison with spontaneous hypomania (bipolar II).
J Affect Disord 2003;73
(1-2)
65- 74
PubMedGoogle Scholar 51.Goldberg
JFTruman
CJ Antidepressant-induced mania: an overview of current controversies.
Bipolar Disord 2003;5
(6)
407- 420
PubMedGoogle Scholar 52.Harel
EVLevkovitz
Y Effectiveness and safety of adjunctive antidepressants in the treatment of bipolar depression: a review.
Isr J Psychiatry Relat Sci 2008;45
(2)
121- 128
PubMedGoogle Scholar 53.Thase
ME Bipolar depression: issues in diagnosis and treatment.
Harv Rev Psychiatry 2005;13
(5)
257- 271
PubMedGoogle Scholar 54.Wheeler Vega
JAMortimer
AMTyson
PJ Conventional antipsychotic prescription in unipolar depression, I: an audit and recommendations for practice.
J Clin Psychiatry 2003;64
(5)
568- 574
PubMedGoogle Scholar 55.Mortimer
AMMartin
MWheeler Vega
JATyson
PJ Conventional antipsychotic prescription in unipolar depression, II: withdrawing conventional antipsychotics in unipolar, nonpsychotic patients.
J Clin Psychiatry 2003;64
(6)
668- 672
PubMedGoogle Scholar 56.Heeringa
MBeurskens
RSchouten
WVerduijn
MM Elevated plasma levels of clozapine after concomitant use of fluvoxamine.
Pharm World Sci 1999;21
(5)
243- 244
PubMedGoogle Scholar 57.Spina
EAvenoso
AScordo
MGAncione
MMadia
AGatti
GPerucca
E Inhibition of risperidone metabolism by fluoxetine in patients with schizophrenia: a clinically relevant pharmacokinetic drug interaction.
J Clin Psychopharmacol 2002;22
(4)
419- 423
PubMedGoogle Scholar 58.Daniel
DGRandolph
CJaskiw
GHandel
SWilliams
TAbi-Dargham
AShoaf
SEgan
MElkashef
ALiboff
S
et al. Coadministration of fluvoxamine increases serum concentrations of haloperidol.
J Clin Psychopharmacol 1994;14
(5)
340- 343
PubMedGoogle Scholar 59.Blanco
CLaje
GOlfson
MMarcus
SCPincus
HA Trends in the treatment of bipolar disorder by outpatient psychiatrists.
Am J Psychiatry 2002;159
(6)
1005- 1010
PubMedGoogle Scholar 60.Hellewell
JS A review of the evidence for the use of antipsychotics in the maintenance treatment of bipolar disorders.
J Psychopharmacol 2006;20
(2)
(suppl)39- 45
PubMedGoogle Scholar 61.Smith
LACornelius
VWarnock
ABell
AYoung
AH Effectiveness of mood stabilizers and antipsychotics in the maintenance phase of bipolar disorder: a systematic review of randomized controlled trials.
Bipolar Disord 2007;9
(4)
394- 412
PubMedGoogle Scholar 62.Segal
JBerk
MBrook
S Risperidone compared with both lithium and haloperidol in mania: a double-blind randomized controlled trial.
Clin Neuropharmacol 1998;21
(3)
176- 180
PubMedGoogle Scholar 63.Tohen
MGreil
WCalabrese
JRSachs
GSYatham
LNOerlinghausen
BMKoukopoulos
ACassano
GBGrunze
HLicht
RWDell’Osso
LEvans
ARRisser
RBaker
RWCrane
HDossenbach
MRBowden
CL Olanzapine versus lithium in the maintenance treatment of bipolar disorder: a 12-month, randomized, double-blind, controlled clinical trial.
Am J Psychiatry 2005;162
(7)
1281- 1290
PubMedGoogle Scholar 64.Ketter
TAHouston
JPAdams
DHRisser
RCMeyers
ALWilliamson
DJTohen
M Differential efficacy of olanzapine and lithium in preventing manic or mixed recurrence in patients with bipolar I disorder based on number of previous manic or mixed episodes.
J Clin Psychiatry 2006;67
(1)
95- 101
PubMedGoogle Scholar 65.Keck
PEOrsulak
PJCutler
AJSanchez
RTorbeyns
AMarcus
RN McQuade
RDCarson
WHCN138-135 Study Group, Aripiprazole monotherapy in the treatment of acute bipolar I mania: a randomized, double-blind, placebo- and lithium-controlled study.
J Affect Disord 2009;112
(1-3)
36- 49
PubMedGoogle Scholar 66.Ito
HKoyama
AHiguchi
T Polypharmacy and excessive dosing: psychiatrists' perceptions of antipsychotic drug prescription.
Br J Psychiatry 2005;187243- 247
PubMedGoogle Scholar 67.Xiang
YTWeng
YZLeung
CMTang
WKUngvari
GS Clinical and social determinants of antipsychotic polypharmacy for Chinese patients with schizophrenia.
Pharmacopsychiatry 2007;40
(2)
47- 52
PubMedGoogle Scholar 68.Rush
AJZimmerman
MWisniewski
SRFava
MHollon
SDWarden
DBiggs
MMShores-Wilson
KShelton
RCLuther
JFThomas
BTrivedi
MH Comorbid psychiatric disorders in depressed outpatients: demographic and clinical features.
J Affect Disord 2005;87
(1)
43- 55
PubMedGoogle Scholar 69.Viola
RCsukonyi
KDoro
PJanka
ZSoos
G Reasons for polypharmacy among psychiatric patients.
Pharm World Sci 2004;26
(3)
143- 147
PubMedGoogle Scholar 70.Stahl
SM Stahl's Essential Psychopharmacology: Neuroscientific Basis and Practical Applications. 3rd ed. New York, NY: Cambridge University Press; 2008
71.Hartung
DMWisdom
JPPollack
DAHamer
AMHaxby
DGMiddleton
L McFarland
BH Patterns of atypical antipsychotic subtherapeutic dosing among Oregon Medicaid patients.
J Clin Psychiatry 2008;69
(10)
1540- 1547
PubMedGoogle Scholar 72.Chen
HReeves
JHFincham
JEKennedy
WKDorfman
JHMartin
BC Off-label use of antidepressant, anticonvulsant, and antipsychotic medications among Georgia Medicaid enrollees in 2001.
J Clin Psychiatry 2006;67
(6)
972- 982
PubMedGoogle Scholar 73.Walton
SMSchumock
GTLee
KVAlexander
GCMeltzer
DStafford
RS Prioritizing future research on off-label prescribing: results of a quantitative evaluation.
Pharmacotherapy 2008;28
(12)
1443- 1452
PubMedGoogle Scholar 74.Thompson
ASullivan
SABarley
MStrange
SOMoore
LRogers
PSipos
AHarrison
G The DEBIT trial: an intervention to reduce antipsychotic polypharmacy prescribing in adult psychiatry wards—a cluster randomized controlled trial.
Psychol Med 2008;38
(5)
705- 715
PubMedGoogle Scholar