Memory-prediction errors and their consequences in schizophrenia.

Cognitive deficits play a central role in the onset of schizophrenia. Cognitive impairment precedes the onset of psychosis in at least a subgroup of patients, and accounts for considerable dysfunction. Yet cognitive deficits as currently measured are not significantly related to hallucinations and delusions. Part of this counterintuitive absence of a relationship may be caused by the lack of an organizing principle of cognitive impairment in schizophrenia research. We review literature suggesting that a system of memory-based prediction is central to human perception, thought and action , and forward the notion that many of the symptoms of schizophrenia are a result of a failure of this system.

A global partnership in medical education between Duke University and the National University of Singapore.

Duke University and the National University of Singapore (NUS) have partnered to launch a new medical school that brings the American style of postbaccalaureate medical education to Asia. The new institution, called the Duke-NUS Graduate Medical School (GMS) and located in Singapore adjacent to the Singapore General Hospital, admitted its inaugural class of students representing citizens of seven nations in August 2007. The project represents an investment of more than $350 million from three ministries of the Singapore government, and a commitment on Duke's part to provide senior leadership and recruit faculty from Duke, from other international locales, and from within Singapore itself. Graduating students who complete the four-year Duke curriculum will receive an MD degree awarded jointly by Duke and NUS, thereby distinguishing this school from medical education in most Asian institutions that award an MBBS degree after a five-year period of study that follows directly from secondary school. The emphasis of the Duke-NUS GMS is to prepare physician-scientists for academic careers, with plans for 20% of each class to complete a combined MD/PhD degree. This article describes events leading up to this partnership and details of the relationship, including curriculum, organizational structure, milestones, and goals.

Chronic pain and depression. III. Family history study of depression and alcoholism in chronic low back pain patients.

In an attempt to unravel the relationship between chronic pain and depression, the authors studied the incidence of depression, alcoholism, and chronic pain in first degree relatives of 100 chronic pain patients with and without depression. A higher incidence of major depression was found in first degree relatives of those patients with depression than those without depression. Familial incidence of alcohol dependence was similar in both groups of patients. These findings confirm an earlier report and raise questions about the notion of considering chronic pain simply as a variant of depression and suggest the possibility that the occurrence of major depression in chronic back pain might be related to genetic vulnerability to depression in these patients.

Zonisamide prevents olanzapine-associated hyperphagia, weight gain, and elevated blood glucose in rats.

Olanzapine (OLZ), one of the second-generation atypical antipsychotics (SGAs), has shown relative advantages in patient adherence and outcomes. However, OLZ has also been associated with a higher incidence of weight gain than most other SGAs. Excessive weight gain may in turn contribute to long-term health concerns for some individuals. Zonisamide (ZNS), a medication approved in the United States as an adjunct in the management of epilepsy, has a diverse pharmacological profile, including sodium channel blockade, monoamine enhancement, and inhibition of carbonic anhydrase. ZNS has also been reported to cause weight loss in both humans and rodents. We hypothesized that this profile might be beneficial when co-administered with OLZ. To test this hypothesis, we evaluated the effects of OLZ on body weight, as well as the pathways known to regulate feeding behavior and arousal in the Sprague-Dawley rat. As indicated via c-Fos expression, we found an OLZ-induced activation in the nucleus accumbens and orexin neurons in the lateral hypothalamus. An OLZ-associated development of hyperphagia, weight gain and elevated blood glucose in the rat was also found. These outcomes were attenuated and reversed in the presence of concomitant ZNS. These results suggest the hypothesis that ZNS may effectively treat or prevent weight gain or metabolic changes associated with the SGAs. Future studies of this combination in patients through appropriately designed human clinical studies are encouraged.