Volumetric analysis of hippocampal sub-regions in late onset depression: a 3 tesla magnetic resonance imaging study.

BACKGROUND: While many studies have reported reduced volume of hippocampus in late onset depression (LOD), the status of hippocampus sub-regions (anterior/posterior) is yet to be explored. Evaluating hippocampal sub-regions might facilitate better elucidation of the neurobiological basis of LOD. METHODS: Twenty five elderly subjects with LOD (mean age=65.28yr, SD=5.73, 15 females) and 20 healthy controls (mean age=65.35yr, SD=5.67, 7 females) were examined using 3-tesla magnetic resonance imaging (MRI). They were also evaluated with Montgomery Asberg Depression Rating Scale (MADRS) and Hindi Mental State Examination (HMSE). We examined the difference in volume of Hippocampal sub-regions between the LOD group and control group controlling for the age, sex and intracranial volume. RESULTS: Left posterior hippocampus volume was significantly smaller in LOD group than the control group (1.01±0.19ml vs 1.16±0.25ml, F=7.50, p=0.009). There was a similar trend for the right posterior hippocampus (1.08±0.19ml vs 1.18±0.27ml, F=3.18, p=0.082). Depression severity (mean MADRS score=20.64±8.99) had a significant negative correlation with volumes of right posterior hippocampus (r=-0.37, p=0.012) and left posterior hippocampus (r=-0.46, p=0.001) in the LOD group. CONCLUSIONS: Specific reduction of posterior hippocampus volume and its relationship with depression severity indicates sub region specific hippocampal volumetric abnormalities in LOD. Future studies need to evaluate sub region specific hippocampal volume in LOD longitudinally for better understanding of the pathogenesis of LOD in view of the functional differences between anterior and posterior hippocampus.

First rank symptoms & facial emotion recognition deficits in antipsychotic naïve schizophrenia: Implications for social threat perception model.

Facial emotion recognition deficits (FERD) have been consistently demonstrated in schizophrenia. However the relation between psychopathology and FERD remains inconclusive. This could possibly be due to the wide heterogeneity in the psychopathology of schizophrenia. First Rank Symptoms (FRS) of schizophrenia is associated with heightened sense of paranoia and rapid processing of threatful emotional stimuli. We studied differences in patterns of FERD between homogenous sub-groups of antipsychotic naïve schizophrenia patients (n=63); namely those experiencing FRS (FRS+ group n=26) and those who did not (FRS- group n=37), in comparison to age-, sex-, education matched healthy controls (n=45). FERD was assessed using TRENDS - (Tool for Recognition of Emotions in Neuropsychiatric DisorderS), a culturally sensitive and ecologically valid (consisting of both static and dynamic emotional stimuli) tool. The total number of images of non threatful emotions (sad, happy, neutral) which were identified as any of the threatful emotions (fear, anger, disgust) and vice versa were calculated and termed TRENDS Over-identification and Under-identification score respectively. The patient group made significantly greater errors in emotion recognition as compared to healthy controls. On post hoc analysis (Tukey HSD) the patients in FRS+ group made significantly greater errors in Over-identification as compared to the FRS- group. This study supports that FERD is one of the important deficits in schizophrenia. There is a differential pattern of impairment in FERD, which supports the role of heightened threat perception in the evolution of psychopathology in schizophrenia patients.

Antithetical asymmetry in schizophrenia and bipolar affective disorder: a line bisection study.

OBJECTIVE: Evolutionary theories link the pathogenesis of psychosis with anomalous brain asymmetry. Research shows that aberrant lateralization is linked to schizophrenia with elevated rates of left-handedness and reversal of normal cerebral asymmetries. However, lateralization is underexamined in bipolar affective disorder (BPAD) and the available literature suggests the possibility of greater lateralization, which is diametrically opposite to what is observed in schizophrenia. For the first time, we report concurrent analyses of asymmetry in BPAD and schizophrenia using a line bisection task. METHODS: We examined 164 subjects (31 patients with BPAD in remission, 30 patients with schizophrenia, and 103 healthy controls) using a two-hand line bisection task with established methodology. Raters with good inter-rater reliability (intraclass correlation coefficient > 0.8) measured deviation from the center. Task performance was compared using analysis of covariance with age, sex, and education as covariates. RESULTS: Study groups did not differ significantly on age, sex, and handedness (p > 0.06). Patients (both schizophrenia and BPAD) had significantly more errors in identifying the center than controls (p < 0.001). Patients with schizophrenia bisected fewer lines at center than controls and BPAD subjects (p < 0.001). Using their right hand, schizophrenia patients had significant rightward deviation and BPAD patients had leftward deviation (p = 0.001). A significant interaction between diagnosis and direction of deviation (p = 0.01) was noted, with significant rightward deviation in schizophrenia and a trend toward leftward deviation in BPAD. CONCLUSIONS: Study findings suggest attenuation of normal pseudoneglect in schizophrenia and accentuation of normal pseudoneglect in BPAD, indicating lesser lateralization in schizophrenia and possibly greater lateralization in BPAD. From an evolutionary perspective, schizophrenia and BPAD might have antithetical origins.

Rimonabant-induced catatonia in schizophrenia: A case report.

SUMMARY: Patients with psychiatric illness have higher rates of mortality and medical co-morbidity related to increased rates of diabetes mellitus and cardiovascular disease. Rimonabant, a cannabinoid receptor (CB1) antagonist, is an anti-obesity agent and decreases risk for metabolic syndrome. Though there are reports of rimonabant associated with adverse psychiatric events like depression, rimonabant-induced catatonia is not reported. In this first time report, we describe a patient with schizophrenia developing catatonia possibly due to rimonabant.: