An evaluation of irreversible psychosurgical treatment of patients with obsessive-compulsive disorder in the Netherlands, 2001-2008.

Admissions for irreversible psychosurgical treatment of obsessive-compulsive disorder (OCD) by the Working Group for Indication Psychosurgery in the Netherlands were analyzed, and the postsurgical effects on symptom severity and quality of life were evaluated. The data were extracted from patient records in the period 2001-2008, and there was a postoperative assessment with a semistructured interview. Fourteen patients applied, having severe OCD with mostly one or more comorbid disorders.

Is there change in intelligence quotient in chronically ill schizophrenia patients? A longitudinal study in twins discordant for schizophrenia.

Background: Intellectual deficits are commonly found in schizophrenia patients. These intellectual deficits have been found to be heritable. However, whether the intellectual deficits change over time and, if so, whether the change is related with an increased genetic risk for the disease are not known.

Does olanzapine inhibit the psychomimetic effects of Δ⁹-tetrahydrocannabinol?

Δ⁹-Tetrahydrocannabinol (THC) produces transient psychomimetic effects in healthy volunteers, constituting a pharmacological model for psychosis. The dopaminergic antagonist haloperidol has previously been shown to reduce these effects. This placebo-controlled, cross-over study in 49 healthy, male, mild cannabis users aimed to further explore this model by examining the effect of a single oral dose of olanzapine (with dopaminergic, serotonergic, adrenergic, muscarinergic and histaminergic properties) or two oral doses of diphenhydramine (histamine antagonist) on the effects of intrapulmonarily administered THC.

Effect of cannabis use on the course of schizophrenia in male patients: a prospective cohort study.

Background: Findings on the impact of cannabis use on the course of schizophrenia are inconsistent and not conclusive.

Aims: To study the effect of cannabis use on the course of schizophrenia taking into account the effects of the quantity of cannabis use and important confounders.

Methods: Prospective cohort study with assessments of symptoms, confounders and hospitalizations at baseline, 6 month and 12 month follow up.

Kraepelin was right: a latent class analysis of symptom dimensions in patients and controls.

Phenotypic heterogeneity within patients and controls may explain why the genetic variants contributing to schizophrenia risk explain only a fraction of the heritability. The aim of this study is to investigate quantitative and qualitative differences in psychosis symptoms in a sample including psychosis patients, their relatives, and community controls. We combined factor analysis and latent class analysis to analyze variation in Comprehensive Assessment of Symptoms and History lifetime-rated symptoms in 4286 subjects.