Effect of cannabis use on cognitive functions and driving ability.

Background: Neither experimental nor epidemiologic approaches have so far given definitive answers to the question of the potential effect of cannabis on driving ability.

Method: To shed more light on this topic, we conducted a placebo-controlled double-blind study including 60 healthy volunteers (a negative urine drug screening test was prerequisite). On the first day, baseline data were obtained from a physical examination and a psychological test battery for the investigation of visual and verbal memory as well as cognitive perceptual performance.

Hippocampal volume reduction in male schizophrenic patients.

Using magnetic resonance imaging of the brain, we examined volumetric measurements of total brain, hemispheres, lateral ventricles and the hippocampus/amygdala complex in male subjects (41 first-episode schizophrenics, 30 chronic schizophrenic patients and 32 healthy controls). We found significantly smaller total brain size in the chronic schizophrenic group, significantly larger lateral ventricles in both patient groups and hippocampal volume reduction bilaterally in first-episode patients (-13.2% left, -12.