[Acute Psychosis after Consumption of Synthetic Cannabinoids]. / Akute Psychose nach Konsum von synthetischen Cannabinoiden.

INTRODUCTION: Mocarz is a Legal high that consists of dried parts of plants mixed with synthetic cannabinoids. There is currently limited information on its acute toxicity. CASE REPORT: We describe a 35-year-old patient with no previous medical and psychiatric history who was admitted to the psychiatric clinic after developing agitation and paranoid psychotic symptoms following the use of Mocarz purchased over the internet. CONCLUSION: Legal highs are a challenge in psychiatric acute care, because they provoke unpredictable mental states endangering self and others.

Impaired probabilistic classification learning with feedback in patients with major depression.

BACKGROUND: The function of basal ganglia (BG) in the pathophysiology of major depression (MD) is still unclear. Recent research found changes in BG regarding size, structure and cerebral perfusion in patients with MD. Neuroimaging shows recruitment of the striatum during feedback (FB) based incidental learning of probabilistic classification learning, while the medial temporal lobe (MTL) is associated with paired associate (PA) based incidental learning. The purpose of this study was to evaluate whether FB-based incidental learning is affected in MD. METHODS: The FB and PA versions of the weather prediction task (WPT), a task of incidental probabilistic classification learning, were completed by patients with MD (n=44) and healthy controls (n=44). In FB-learning the participants received either a "thumbs-up" or "thumbs-down" message according to their right or wrong classification of cards to a certain kind of weather (either rainy or fine), while in PA learning no classification was required. Severity of MD was rated on the Beck Depression Inventory and Hamilton Rating Scale for depression. RESULTS: Patients with MD were selectively impaired on the FB task relative to controls (p<0.05), while no significant difference was found for PA learning between the two groups. Furthermore, there were no significant differences between FB and PA-learning within the patient and control groups. CONCLUSION: Our results indicate a distinct impairment on the FB-based version of the weather prediction task. These findings implicate disturbed reinforcement learning in this group of patients.