Pattern of brain activation during social cognitive tasks is related to social competence in siblings discordant for schizophrenia.

Measures of social competence are closely related to actual community functioning in patients with schizophrenia. However, the neurobiological mechanisms underlying competence in schizophrenia are not fully understood. We hypothesized that social deficits in schizophrenia are explained, at least in part, by abnormally lateralized patterns of brain activation in response to tasks engaging social cognition, as compared to healthy individuals. We predicted such patterns would be partly heritable, and therefore affected in patients' nonpsychotic siblings as well. We used a functional magnetic resonance image paradigm to characterize brain activation induced by theory of mind tasks, and two tests of social competence, the Test of Adaptive Behavior in Schizophrenia (TABS), and the Social Skills Performance Assessment (SSPA) in siblings discordant for schizophrenia and comparable healthy controls (n = 14 per group). Healthy individuals showed the strongest correlation between social competence and activation of right hemisphere structures involved in social cognitive processing, whereas in patients, the correlation pattern was lateralized to left hemisphere areas. Unaffected siblings of patients exhibited a pattern intermediate between the other groups. These results support the hypothesis that schizophrenia may be characterized by an abnormal functioning of nondominant hemisphere structures involved in the processing of socially salient information.

Relation of depression to heart rate nonlinear dynamics in patients > or =60 years of age with recent unstable angina pectoris or acute myocardial infarction.

Depression is common among older patients and it has been related to a worsened coronary prognosis. The basis for this association is controversial. The aim of this study was to ascertain whether patients with a recent acute coronary event show depression-related changes of heart rate variability (HRV) nonlinear dynamics. Alterations of the HRV have been recently shown to predict mortality in patients recovering from an acute myocardial infarction. In 52 patients > or =60 years (52% women) with recent (within 24 to 72 hours) unstable angina pectoris or myocardial infarction, we obtained conventional time- and frequency-domain HRV measurements, along with nonlinear HRV measurements, including SD of the instantaneous beat-to-beat variability (SD1), scaling exponent alpha1 (alpha1), and approximate entropy (ApEn) from 10-minute RR-interval recordings. We also evaluated the presence of clinical depression and measured its severity by means of a 21-item Hamilton Depression Scale. On admission to the coronary care unit, 19 patients (37%) were depressed; alpha1 was higher (1.23 +/- 0.21 vs 1.03 +/- 0.30, p <0.05), whereas SD1 (10.4 +/- 3.7 vs 14.4 +/- 7.3, p <0.05) and ApEn (0.98 +/- 0.22 vs 1.16 +/- 0.15, p <0.001) were lower in depressed patients. Also, alpha1 increased (r = 0.31, p <0.05) and both SD1 (r = -0.46, p <0.01) and ApEn (r = -0.28, p <0.05) decreased with worsening depressive symptoms. In our sample, depression was associated with increased correlation and decreased complexity of the interbeat interval time series in older adults who had recently developed an acute coronary syndrome.