Ferrarelli et alArticle used transcranial magnetic stimulation with simultaneous high-density electroencephalographic recordings to show a slowing of the main oscillatory frequency (natural frequency) of frontal cortical areas in schizophrenic patients. The prefrontal natural frequency of schizophrenic patients was slower than in any control subject. Moreover, it was negatively correlated with positive Positive and Negative Syndrome Scale scores and reaction time in a word memory task.
This meta-analysis by Howes et alArticle brings together more than 50 studies and nearly 3 decades of work on the nature of the dopaminergic dysfunction in schizophrenia. Contrary to initial ideas, it shows there is little, if any, alteration in D2/3 receptor availability but there is a large elevation in presynaptic dopaminergic function in schizophrenia.
Johnson et alArticle conducted a study examining neuromotor functioning and habituation in 6-month-old infants prenatally exposed to psychotropic medications. The findings showed lower scores on a screening measure of neuromotor performance in infants exposed to antipsychotic medication but no significant differences between antidepressant-exposed and unexposed infants. Maternal psychiatric illness and postnatal antipsychotic exposure via lactation also predicted infant outcomes.
Wilhelm et alArticle compared the efficacy of a comprehensive behavioral intervention for tics with supportive treatment in a multisite trial of 122 adults with Tourette syndrome. After 10 weeks of treatment, the behavioral intervention was superior to supportive treatment in reducing tic severity and a significantly higher percentage of subjects in the behavioral intervention were rated much improved or very much improved.
Nichols et alArticle investigated the effects of age and apolipoprotein E (APOE) ϵ4, a genetic risk factor for Alzheimer disease, on the neural substrate of episodic memory using functional magnetic resonance imaging. In healthy volunteers, genotype affected age-associated changes in hippocampal blood oxygen level–dependent activation. APOE ϵ4 carriers failed to manifest the decreased activation with age observed with the other 2 genotypes. The stepwise pattern of activation among genotype groups mirrors the order of susceptibility to Alzheimer disease.
Sebastian et alArticle demonstrate that boys with conduct problems show reduced amygdala and insula activity to emotional scenarios. Unique variance associated with conduct disorder symptoms correlated positively with amygdala response, while unique variance associated with callous-unemotional traits correlated negatively with activity in this region.
In a prospective study of 1 095 338 men, Gale et alArticle investigated associations between mental disorders diagnosed on military conscription at age 18 years and later hospital admission and mortality during a mean 22.6 years of follow-up. Diagnosis of mental disorder was linked with an increased risk of premature death that was not confined to those whose illness was severe enough for hospitalization or to those with psychotic or substance use disorders.
In a study by Tolin et alArticle, patients with hoarding disorder, patients with obsessive-compulsive disorder, and healthy controls underwent functional magnetic resonance imaging while deciding whether to keep or discard possessions. When deciding about items that did not belong to them, patients with hoarding disorder showed relatively lower activity in the insula and anterior cingulate cortex. However, when deciding about items that belonged to them, these regions showed excessive functional magnetic resonance imaging signal compared with the other groups.
Becket alArticle examined multimodal magnetic resonance imaging data of detoxified alcohol-dependent patients with respect to subsequent relapse. Relapsers showed more pronounced and spatially extended atrophy than abstainers and enhanced brain response on alcohol-associated stimuli in a medial prefrontal brain area related to attentional bias toward drug cues. In contrast, abstainers displayed an increased brain response in the midbrain (the ventral tegmental area extending into the subthalamic nucleus) and a stronger functional connectivity between the midbrain and areas associated with processing of aversive stimuli.
In a large meta-analysis, Hartz et alArticle found that the association between CHRNA5 genotype and smoking is stronger among early-onset smokers. This suggests a biological mechanism for the epidemiological observation that early-onset smokers are more likely to be heavy smokers.
This Month in Archives of General Psychiatry. Arch Gen Psychiatry. 2012;69(8):763. doi:10.1001/archgenpsychiatry.2011.1219