Wehr et alArticle report that patients with seasonal affective disorder (SAD) produce a signal of change of season, expressed in the duration of nightly melatonin secretion, that is similar to one that mammals use to regulate seasonal behavior and that is absent in healthy individuals. This is the first demonstration in SAD of an abnormality in a system that regulates seasonal behavior in animals. While the study does not establish causality, it raises the possibility that the melatonin signal induces winter depression in susceptible individuals.
A commentary by Michael Terman is included.Article
Hulshoff Pol et alArticle found that gray matter density was decreased in distinct focal brain areas in the brains of schizophrenic patients, including the left amygdala (more pronounced in older patients), left hippocampus, thalamus, (orbito)frontal, (superior)temporal, occipitotemporal, precuneus, posterior cingulate, and insular gyri bilaterally. These findings suggest that (progressive) tissue loss in specific neuronal networks may be related to the pathogenesis of schizophrenia.
Among the many risk factors for depression in youth, 2 of the most potent include having subdiagnostic symptoms of depression and having a depressed parent. In a randomized, targeted prevention trial of youth with both these risk factors, Clarke et alArticle found significantly fewer prospective depression episodes and better functioning among adolescent offspring completing a brief group cognitive therapy prevention program, relative to youth receiving usual care.
Myin-Germeys et alArticle reported that patients with psychosis and their first-degree relatives reacted with more intense emotions to subjective appraisals of stress in daily life than controls. Subtle alterations in the way persons interact with their environment may, therefore, constitute part of the vulnerability for psychotic illness.
Lyons et alArticle report that postnatal stress has minimal effects on hippocampal volumes determined in monkeys by high-resolution magnetic resonance imaging. Their study suggests that small hippocampi are an inherited characteristic of the brain. This probably represents a polygenic trait, and not the effect of a single major gene. Clinical studies should therefore assess whether heritable aspects of hippocampal morphology diminish neuroendocrine negative feedback regulation and thereby contribute to excessive stress levels of cortisol in patients with major depression.
Noël et alArticle examined whether frontal lobes are highly vulnerable to chronic consumption of alcohol according to the frontal vulnerability hypothesis. Specific neuropsychological tasks assessing executive (or "nonautomatic functions"; eg, inhibition, coordination of dual-task) and executive (eg, verbal span) functions were used. Recently detoxified alcoholics performed tasks involving nonexecutive functions as well as controls but did less well in almost all tasks involving executive functions.
Ray et alArticle conducted a retrospective cohort study in Tennessee Medicaid patients that found a dose-related association between antipsychotic drug use and sudden death. Patients receiving the equivalent of more than 100 mg of thioridazine or its equivalent had a 2.4-fold increased risk. Although the study data cannot demonstrate causality, they suggest that the potential adverse cardiac effects of antipsychotics should be considered in clinical practice, particularly for patients with cardiovascular disease.
A commentary by Zarate and Patel is included.Article
Using a retrospective cohort design, Lund et alArticle compared the risk of developing diabetes, hyperlipidemia and hypertension in patients with schizophrenia receiving clozapine vs conventional antipsychotics. Overall, clozapine was not associated with an increased risk of any of these outcomes. However, a significantly increased risk of diabetes and hyperlipidemia was observed among younger patients (aged 20-34 years) receiving clozapine.
This Month in Archives of General Psychiatry. Arch Gen Psychiatry. 2001;58(12):1099. doi:10.1001/archpsyc.58.12.1099