Hippocampal Subfield Volumes in Patients With First-Episode Psychosis.

Background: Hippocampal abnormalities have been largely reported in patients with schizophrenia and bipolar disorder, and are considered to be involved in the pathophysiology of the psychosis. The hippocampus consists of several subfields but it remains unclear their involvement in the early stages of psychosis. Aim: The aim of this study was to investigate volumetric alterations in hippocampal subfields in patients at the first-episode psychosis (FEP). Methods: Magnetic resonance imaging (MRI) data were collected in 134 subjects (58 FEP patients; 76 healthy controls [HC]). A novel automated hippocampal segmentation algorithm was used to segment the hippocampal subfields, based on an atlas constructed from ultra-high resolution imaging on ex vivo hippocampal tissue. The general linear model was used to investigate volume differences between FEP patients and HC, with age, gender and total intracranial volume as covariates. Results: We found significantly lower volumes of bilateral CA1, CA4, and granule cell layer (GCL), and of left CA3, and left molecular layer (ML) in FEP patients compared to HC. Only the volumes of the left hippocampus and its subfields were significantly lower in FEP than HC at the False Discovery Rate (FDR) of 0.1. No correlation was found between hippocampal subfield volume and duration of illness, age of onset, duration of medication, and Positive and Negative Syndrome Scale (PANSS). Conclusion: We report abnormally low volumes of left hippocampal subfields in patients with FEP, sustaining its role as a putative neural marker of psychosis onset.

A meta-analysis of efficacy and safety of aripiprazole in adult and pediatric bipolar disorder in randomized controlled trials and observational studies.

BACKGROUND: Aripiprazole (ARP) has been shown to be effective in the treatment of bipolar disorder (BD). However, no prior investigation considered both randomized clinical trials (RCTs) and non-RCTs. We here evaluated the efficacy and safety of ARP compared with placebo (PCB) and other drugs at 3- and 12-weeks in adult and pediatric population including, for the first time, both observational and controlled studies. METHODS: All studies were systematically located by searching electronic sources (EMBASE, MEDLINE, CINHAIL, PsychINFO, Cochrane Central Register of Controlled Trials, Scopus and ClinicalTrials.gov) till June 30th, 2015. The primary outcome was ARP efficacy (mean change from baseline in Young Mania Rating Scale); secondary outcomes regarded acceptability and safety. Results Sixteen RCTs and 6 non-RCTs met our inclusion criteria; 2505 and 2932 patients were included in the analyses of acute and stabilization phase, respectively. In both the acute and stabilization phases ARP efficacy was superior to PCB and comparable to other drugs. The safety profile was similar to other drugs considering in particular sedation, akathisia, weight gain, extrapyramidal and gastroenteric symptoms, with a significant lower risk of hyperprolactinemia particularly at 12-weeks. LIMITATIONS: Data on failed trials are generally limited. CONCLUSIONS: ARP resulted to be an effective treatment in children and adults with BD at 3- and 12-weeks both in a controlled experimental setting or in the real world clinical practice, being poorly associated with hyperprolactinemia. Larger studies are needed to confirm our results related to the maintenance phases and to the pediatric bipolar population.

White matter metabolism differentiates schizophrenia and bipolar disorder: a preliminary PET study.

Fluorodeoxyglucose-F18 positron emission tomography studies (FDG-PET) have shown similar corticolimbic metabolic dysregulation in bipolar disorder and schizophrenia, with hypoactive prefrontal cortex coupled with hyperactive anterior limbic areas. However, it is not clear whether white matter metabolism connecting these regions is differently affected in the two disorders. Twenty-six patients with schizophrenia (mean age ± S.D.=30.23 ± 9.7 year-old; 19 males; mean weight ± S.D.=71 ± 3 kg) and 26 patients with bipolar disorder (mean age ± S.D.=48.73 ± 13 year-old; 18 males; mean weight ± S.D.=75 ± 15 kg) underwent an FDG-PET scan. Normalized datasets the two groups of patients were compared on a voxel-by-voxel basis using a two-sample t statistic test as implemented in SPM8, and adding age as covariate. Group differences were assessed applying a threshold of p<0.0005. White matter metabolic rates significantly differed between schizophrenia and bipolar disorder, whereas no differences were shown for cortical activity. This is the first FDG-PET, to our best knowledge, directly comparing subjects with schizophrenia to those with bipolar disorder. It reports decreased activity in the center of large fronto-temporal and cerebellar white matter tracts in patients with schizophrenia in respect to those with bipolar disorder. This feature may characterize and differentiate the regional brain metabolism of the two illnesses.