Uhl and Grow (SEE ARTICLE) have used estimates of the economic impact of prominent neuropsychiatric disorders in the United States, overall heritabilities, and single-gene inheritance to calculate the effect of complex genetics in psychiatry and neurology. The large effect of oligogenic and polygenic inherited influences motivates efforts to identify the gene variants involved for better prevention and treatment.
Palmer et al (SEE ARTICLE) evaluated treatment-related decisional capacity among middle-aged and older patients with schizophrenia. Overall, patients with schizophrenia showed less understanding of treatment disclosures than healthy subjects. However, there was also considerable heterogeneity in decisional capacity among patients. Decisional capacity in patients with schizophrenia was predicted not by demographic characteristics or severity of psychopathology but by neuropsychological performance. Consideration of cognitive functions may be more relevant to patients' decisional capacity than demographics or psychopathology.
Van der Stelt et al (SEE ARTICLE) assessed event-related brain potentials (ERPs) in patients with schizophrenia and healthy subjects. Patients with schizophrenia displayed deficits in the P3 component but not in earlier-occurring sensory-evoked or cognitive-related ERP components. These findings suggest that high-level attention-dependent cognitive deficits central to schizophrenia do not originate from preceding deficits at lower levels of information processing.
Wade et al (SEE ARTICLE) used opposite-sex and same-sex dizygotic twins to examine associations with bulimia nervosa (BN) status in one twin with psychopathology in the co-twin. Familial or nonfamilial shared risk factors existed between BN and generalized anxiety disorder, neuroticism, psychoactive substance use, novelty seeking, major depression, and panic disorder. The shared risk factors between BN and general anxiety disorder and novelty seeking are only present in men, suggesting a familial, sex-specific manifestation.
Nelson et al (SEE ARTICLE) examined the genetic epidemiology of alcohol-induced blackouts in a young adult Australian twin panel. They found the heritability of lifetime blackouts to be 53% and of having 3 or more blackouts in a year to be 58%. Models that controlled for respondents' frequency of intoxication found evidence for a significant shared genetic contribution unique to risk for blackouts.
In the treatment of cocaine dependence, no effective pharmacological intervention has been identified. Carroll et al (SEE ARTICLE) conducted a randomized, placebo controlled, double-blind trial comparing disulfiram with a placebo and cognitive behavioral therapy with interpersonal therapy. Results suggested that disulfiram and cognitive behavioral therapy are effective therapies for cocaine-dependent individuals and that disulfiram may exert a direct effect on cocaine use rather than through reducing concurrent alcohol use.
Weissman et al (SEE ARTICLE) follow up findings from their genetic linkage study that suggested a possible panic disorder (PD) syndrome, including bladder problems, thyroid disorders, chronic headaches and migraine, and mitral valve prolapse. Patients with interstitial cystitis diagnosed by urodynamics or cystoscopy as compared with control subjects had higher rates of PD and most of the other syndrome conditions as did their first-degree relatives. The possibility of a familial pleiotropic syndrome that may include interstitial cystitis and PD deserves further investigation.
Children with fragile X (fraX) suffer from impaired social functioning, which often includes eye gaze aversion. Garrett et al (SEE ARTICLE) used functional magnetic resonance imaging to determine whether individuals with fraX show aberrant brain activation in response to eye gaze and face stimuli. Individuals with fraX had decreased activation of the superior temporal sulcus compared with control subjects, indicating deficits in the perception of eye gaze. Subjects with fraX also lacked specificity of fusiform gyrus activation to face orientation, suggesting an absence of the normal preference for forward faces rather than angled faces.
In a 2-site neuroimaging study, Lotspeich et al (SEE ARTICLE) assessed possible neuroanatomical differences between Asperger disorder and autism to determine whether these conditions align themselves along a severity continuum or constitute distinct biological entities. Cerebral gray tissue volume findings suggest that Asperger disorder is at one end of the autism spectrum. However, exploratory assessments of brain-IQ relationships indicate neurodevelopmental differences between Asperger disorder and high-functioning autism.
Previous studies have provided evidence that bipolar disorder is associated with abnormalities of mitochondrial function, resulting in abnormal energy metabolism. Konradi et al (SEE ARTICLE) examined messenger RNA expression in the hippocampus of patients with bipolar disorder and schizophrenia using microarray technology. They found evidence for relatively specific decreased expression of genes regulating mitochondrial function in support of the hypothesis of abnormal energy metabolism in bipolar disorder.
Gueorguieva and Krystal (SEE ARTICLE) review methods for analysis of repeated measures data, illustrate the advantages of mixed-effect models, and assess the extent of the shift from traditional to mixed-effect approaches in published reports in the ARCHIVES.
