Increased fronto-striatal reward prediction errors moderate decision making in obsessive-compulsive disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) has been linked to functional abnormalities in fronto-striatal networks as well as impairments in decision making and learning. Little is known about the neurocognitive mechanisms causing these decision-making and learning deficits in OCD, and how they relate to dysfunction in fronto-striatal networks. METHOD: We investigated neural mechanisms of decision making in OCD patients, including early and late onset of disorder, in terms of reward prediction errors (RPEs) using functional magnetic resonance imaging. RPEs index a mismatch between expected and received outcomes, encoded by the dopaminergic system, and are known to drive learning and decision making in humans and animals. We used reinforcement learning models and RPE signals to infer the learning mechanisms and to compare behavioural parameters and neural RPE responses of the OCD patients with those of healthy matched controls. RESULTS: Patients with OCD showed significantly increased RPE responses in the anterior cingulate cortex (ACC) and the putamen compared with controls. OCD patients also had a significantly lower perseveration parameter than controls. CONCLUSIONS: Enhanced RPE signals in the ACC and putamen extend previous findings of fronto-striatal deficits in OCD. These abnormally strong RPEs suggest a hyper-responsive learning network in patients with OCD, which might explain their indecisiveness and intolerance of uncertainty.

Effectiveness of inpatient drug detoxification: links between process and outcome variables.

The Psychiatric University Hospital of Zürich offers a 2-week residential detoxification treatment program for patients abusing illegal drugs. 96 out of 160 patients were interviewed at three intervals: upon admission, on the 10th day of treatment, and about 1 month after leaving the clinic. Approximately 17% of the patients were completely abstinent 1 month after treatment. About 50% of the patients could give up the consumption of particular drugs. For around one third of the dependents, the drug consumption remained the same or had increased. The analysis of the predictors of drug consumption after treatment stresses the importance of the social integration of the dependents before detoxification as well as of characteristics of the treatment process (relapse, dropping out of treatment, and referral to a follow-up program).

Comparison of four groups of substance-abusing in-patients with different psychiatric comorbidity.

OBJECTIVE: Comparisons of different groups of dual patients are rare, yet potential differences could have therapeutic implications. In this study, four groups of psychiatric in-patients with substance use disorder were compared to each other: patients with no psychiatric comorbidity, patients with comorbid schizophrenia and patients with affective and personality disorder. METHOD: Apart from sociodemographic, therapy-related variables and a detailed survey of their substance use, all subjects were assessed with BPRS and SCL-90-R. RESULTS: No differences were found in the patients' demography, psychosocial adjustment and substance consumption career. Significant differences were found in regard to some therapy variables reflecting adherence to treatment and global outcome and to the level of psychopathology. CONCLUSION: Both substance use and comorbid psychiatric disorder have a variable impact on distinct areas of patients' general condition and functioning. The group with comorbid affective disorder appeared to be the most difficult to treat and the therapeutic approach to this disorder deserves reconsideration.

Primary osteosarcoma of the liver.

Extraskeletal osteosarcomas are infrequent, and those that arise within parenchymal organs are very rare indeed. This case of a 71-year-old man with a primary osteosarcoma of the liver is the second reported in man. Pathologic findings, including ultrastructural features, at surgery and autopsy are presented. The differential diagnosis is discussed in detail.

[Pharmacotherapy of generalized anxiety disorder: state of the art]. / Pharmacothérapie de l'anxiété généralisée: etat actuel.

A large percentage of patients in primary care suffer from Generalized Anxiety Disorder (GAD). A task force of the Swiss GAD Society has reviewed the scientific literature and has developed treatment recommendations. Basic treatment, adjunctive treatment and therapy of specific problems like insomnia and comorbidities are differentiated. Newer antidepressants are recommended as basic treatment, especially venlafaxine and paroxetine, which are licensed for that indication.