Widespread abnormality of the γ-aminobutyric acid-ergic system in Tourette syndrome.

Dysfunction of the γ-aminobutyric acid-ergic system in Tourette syndrome may conceivably underlie the symptoms of motor disinhibition presenting as tics and psychiatric manifestations, such as attention deficit hyperactivity disorder and obsessive-compulsive disorder. The purpose of this study was to identify a possible dysfunction of the γ-aminobutyric acid-ergic system in Tourette patients, especially involving the basal ganglia-thalamo-cortical circuits and the cerebellum. We studied 11 patients with Tourette syndrome and 11 healthy controls.

Factor analysis of obsessive-compulsive disorder YBOCS-SC symptoms and association with 5-HTTLPR SERT polymorphism.

Symptoms defining obsessive-compulsive disorder (OCD) are diverse. Factor analyses of OCD symptoms have been used to evaluate obsessive-compulsive phenotypes that are thought to be more homogenous than the macro phenotype. There is evidence that three factors (symmetry/ordering, obsessions/checking, and hoarding) are familial and preliminary evidence that repetitive rituals are associated with a functional polymorphism in the promotor region of the serotonin transporter gene (5-HTTLPR).

Obsessive-compulsive disorder symptom dimensions show specific relationships to psychiatric comorbidity.

The goals of this study were to examine relationships among symptom categories in obsessive-compulsive disorder (OCD), to establish OCD symptom dimensions by factor- and cluster-analytic analyses, and to explore associations between OCD symptom dimensions and comorbid neuropsychiatric conditions. A total of 317 OCD participants underwent a systematic diagnostic interview using the Structured Clinical Interview for DSM-IV. OCD symptoms assessed by the Yale-Brown Obsessive-Compulsive Scale Symptom Checklist (N=169) and by the Thoughts and Behaviors Inventory (N=275) were subjected to factor and cluster analyses.

Diagnostic interview assessed neuropsychiatric disorder comorbidity in 334 individuals with obsessive-compulsive disorder.

Is obsessive-compulsive disorder (OCD) a discrete disorder? Three hundred thirty-four individuals with OCD were interviewed using the Structured Clinical Interview for DSM (SCID). Results demonstrate that OCD is highly comorbid with other neuropsychiatric disorders, with 92% of OCD study participants receiving one or more additional Axis I DSM diagnoses. Among these additional diagnoses, lifetime mood disorders (81%) and anxiety disorders (53%) were the most prevalent.

A high-density genome scan detects evidence for a bipolar-disorder susceptibility locus on 13q32 and other potential loci on 1q32 and 18p11.2.

Bipolar disorder is a severe mental illness characterized by mood swings of elation and depression. Family, twin, and adoption studies suggest a complex genetic etiology that may involve multiple susceptibility genes and an environmental component. To identify chromosomal loci contributing to vulnerability, we have conducted a genome-wide scan on approximately 396 individuals from 22 multiplex pedigrees by using 607 microsatellite markers.

Suggestive evidence for a schizophrenia susceptibility locus on chromosome 6q and a confirmation in an independent series of pedigrees.

We have investigated whether there is a locus on chromosome 6 that confers an increased susceptibility to schizophrenia using a two-stage approach and nonparametric linkage analysis. Allele sharing identical by descent (IBD) and multipoint maximum likelihood score (MLS) statistics were employed. Results from two tested data sets, a first data set, or genome scanning data set, and a second replication data set, show excess allele sharing for multiple markers in 6q, a chromosomal region not previously reported as linked to schizophrenia.

Initial genome scan of the NIMH genetics initiative bipolar pedigrees: chromosomes 4, 7, 9, 18, 19, 20, and 21q.

An initial genome scan was performed on 540 individuals from 97 families segregating bipolar disorder, collected through the National Institutes of Mental Health Genetics Initiative. We report here affected-sib-pair (ASP) data on 126 marker loci (approximately 68,000 genotypes) mapping to chromosomes 4, 7, 9, 18, 19, 20, and 21q, under three affection status models. Modest increases in identical-by-descent (IBD) allele sharing were found at the following loci: D4S2397 and D4S391 (P < 0.

A linkage study of bipolar illness.

Background: Although genetic epidemiological studies of bipolar (BP) illness are consistent with a heritable component, inherited risk factors remain unknown. The goal of the present study is to describe the localization of BP susceptibility loci through linkage strategies, including a genome-wide search.

Methods: A linkage study of 22 BP families has been performed.

Psychiatric disorders in the first-degree relatives of probands with bulimia nervosa.

Data from a family study of psychiatric disorders showed higher rates of major affective disorders, eating disorders, and alcoholism in first-degree relatives of 40 bulimic probands than in first-degree relatives of 24 control subjects. More importantly, the data showed higher rates of major affective disorders in relatives of bulimic probands who themselves had no history of major affective disorders than in relatives of control subjects. This significant finding indicates a familial relationship between bulimia nervosa and major affective disorders, which suggests the possibility of a common diathesis.

Clinical features of illness in siblings with schizophrenia or schizoaffective disorder.

Evidence implicating genetic or prenatal-perinatal environmental causes in the familial aggregation of schizophrenia led us to study 53 sets of siblings, two or more of whom had chronic psychosis, either schizophrenia or schizoaffective disorder. We looked for similarities in clinical features and concordance of diagnosis within sibships to test for shared familial causes. Clinical variables, including diagnosis, specific symptoms, age at onset, and nongenetic perinatal factors, were studied.