Possible association between social cognition and metabolic dysfunctions in Bipolar Disorder and Schizophrenia: Preliminary results.

BACKGROUND: Social cognition (SC) and Theory of Mind (ToM) are compromised in patients with Schizophrenia (SKZ) and Bipolar Disorder (BD) and an increased frequency of metabolic abnormalities is reported in both disorders. Obesity seems associated with cognitive impairments The aim of our study is thus to assess the relationship between obesity and ToM in SKZ and BD. METHODS: 36 stabilized outpatients (18 SKZ and 18 BD) were recruited and completed Reading the Mind in the Eyes Test, Italian version and Faux Pas Recognition Test, adult version. BMI was calculated from self-reported height and weight. Two different Generalized Linear Models were created including performance in Eyes test and in Faux Pas test as outcomes and BMI as covariate. RESULTS: After stratifying for sex, we found a significant relationship between BMI and Faux Pas performance for male patients (p = 0.017), without significant interactions between sex and diagnosis. These results suggest a BMI effect on both affective and cognitive ToM in male patients. LIMITATIONS: Major confounders need to be considered: the greater number of subjects with SKZ in male subsample, a possible influence of neurocognitive performance, small sample size and self-reported BMI. CONCLUSIONS: There could be a relationship between ToM and metabolic dysfunctions, at least in male patients. The exact nature of this relationship has yet to be determined; an interesting theoretical framework is based on a combination of increased brain energy request and inefficient peripheral compensatory mechanisms, resulting in inefficient energy allocation to the brain.

Structural and metabolic differentiation between bipolar disorder with psychosis and substance-induced psychosis: An integrated MRI/PET study.

BACKGROUND: Bipolar disorder (BD) may be characterized by the presence of psychotic symptoms and comorbid substance abuse. In this context, structural and metabolic dysfunctions have been reported in both BD with psychosis and addiction, separately. In this study, we aimed at identifying neural substrates differentiating psychotic BD, with or without substance abuse, versus substance-induced psychosis (SIP) by coupling, for the first time, magnetic resonance imaging (MRI) and positron emission tomography (PET). METHODS: Twenty-seven BD type I psychotic patients with (n=10) or without (n=17) substance abuse, 16 SIP patients and 54 healthy controls were enrolled in this study. 3T MRI and 18-FDG-PET scanning were acquired. RESULTS: Gray matter (GM) volume and cerebral metabolism reductions in temporal cortices were observed in all patients compared to healthy controls. Moreover, a distinct pattern of fronto-limbic alterations were found in patients with substance abuse. Specifically, BD patients with substance abuse showed volume reductions in ventrolateral prefrontal cortex, anterior cingulate, insula and thalamus, whereas SIP patients in dorsolateral prefrontal cortex and posterior cingulate. Common alterations in cerebellum, parahippocampus and posterior cingulate were found in both BD with substance abuse and SIP. Finally, a unique pattern of GM volumes reduction, with concomitant increased of striatal metabolism, were observed in SIP patients. CONCLUSIONS: These findings contribute to shed light on the identification of common and distinct neural markers associated with bipolar psychosis and substance abuse. Future longitudinal studies should explore the effect of single substances of abuse in patients at the first-episode of BD and substance-induced psychosis.

Affective temperament in the eating disorders.

BACKGROUND: In this study, we investigate the affective temperamental characteristics in a sample of ED (eating disorder) patients. METHODS: 49 ED patients diagnosed by the SCID (Structured Clinical Interview for DSM-IV), were divided into two groups on the basis of the presence or absence of Binge Eating (restricting-anorexia nervosa [R-AN]= 16; Binge Eaters= 33). All patients were administered the TEMPS-I (Temperament Evaluation Memphis Pisa Semistructured - Interview), to assess affective temperament. A third group of controls (N= 1010), derived from a study with the TEMPS-I on normal subjects, was included for comparison. RESULTS: A full affective temperament was not found in patients of the restricting group. By contrast 24% of the binge eating group had a full affective temperament of one of three types. Comparing the three temperaments for the three groups, only cyclothymic temperament proved to be significant, with higher levels in the binge eating group (p<0.01). CONCLUSIONS: In this study, people with R-AN do not show a full affective temperament. However, people with binge eating, had depressive and hyperthymic temperament, and displayed higher level of cyclothymic temperament than the normal population. The findings of this study add to a growing literature on temperament in people with ED; particularly, they add to the view that may be various paths leading to R-AN, and these may differ from those of binge eating.