Cerebellar parcellation in schizophrenia and bipolar disorder.

OBJECTIVE: The cerebellum is involved in cognitive processing and emotion control. Cerebellar alterations could explain symptoms of schizophrenia spectrum disorder (SZ) and bipolar disorder (BD). In addition, literature suggests that lithium might influence cerebellar anatomy. Our aim was to study cerebellar anatomy in SZ and BD, and investigate the effect of lithium. METHODS: Participants from 7 centers worldwide underwent a 3T MRI. We included 182 patients with SZ, 144 patients with BD, and 322 controls. We automatically segmented the cerebellum using the CERES pipeline. All outputs were visually inspected. RESULTS: Patients with SZ showed a smaller global cerebellar gray matter volume compared to controls, with most of the changes located to the cognitive part of the cerebellum (Crus II and lobule VIIb). This decrease was present in the subgroup of patients with recent-onset SZ. We did not find any alterations in the cerebellum in patients with BD. However, patients medicated with lithium had a larger size of the anterior cerebellum, compared to patients not treated with lithium. CONCLUSION: Our multicenter study supports a distinct pattern of cerebellar alterations in SZ and BD.

The effects of ghrelin on sleep, appetite, and memory, and its possible role in depression: A review of the literature.

OBJECTIVES: Ghrelin is an orexigenic digestive hormone that plays a role in sleep and memory. Our work aims is to synthesize the effects of ghrelin on appetite, sleep and memory, and also to evidence its role in depressive disorders. METHODS: A systematic search was carried out on PubMed with no time boundaries. The following MeSH terms were used: ghrelin AND (appetite regulation OR obesity), (sleep wake disorders OR sleep) (memory OR cognition disorders) (depression OR depressive disorder OR mood disorder). RESULTS: Ghrelin triggers appetite and alters meal patterns by making them longer and richer. This can lead to pathologies, obesity and insulin-resistance. Ghrelin seems to have a favourable effect on sleep in human beings. It tends to make sleep more efficacious and better quality. Finally, it seems to have an effect on synaptic plasticity in the zones involved in memory and it has been shown to improve memory capacity in rodents. Regarding depression, the administration of ghrelin leads to an anti-depressive effect in animals and in humans. Conversely, post anti-depressant ghrelin titrations have generally shown a decrease in ghrelin levels. Resistant patients seem to retain high levels. Finally, the seriousness of depression could be related to ghrelin levels. CONCLUSION: Ghrelin plays a probable part in depression, especially for particular endophenotypes. A better understanding of ghrelin in depression could potentially help to optimize future therapeutic treatments.

PPAR-γ Agonists for the Treatment of Major Depression: A Review.

Introduction: Selective agonists of the nuclear transcription factor peroxisome proliferator-activated receptor-gamma (PPAR-γ) are used for the treatment of type 2 diabetes. We reviewed their efficacy and safety for the treatment of major depression and the association of their potential antidepressant effects with changes in biomarkers of metabolism and inflammation. Methods: From 8 studies, 4 open-label trials, and 4 randomized controlled trials (RCT) (3 vs. placebo and 1 vs. metformin), 448 patients with major depression were included, of which 209 patients received PPAR-γ agonists (pioglitazone or rosiglitazone) for 6-12 weeks, either alone or in add-on therapy to conventional treatments. Results: PPAR-γ agonists have antidepressant effects in the 4 open-label studies and in 3 out of 4 RCT. No major adverse event was reported. Improvement in depression scores was associated with improvement in 3 biomarkers of insulin resistance (homeostatic model assessment [HOMA-IR], oral glucose tolerance test, and fasting plasma glucose) and 1 biomarker of inflammation (interleukin-6) among 21 biomarkers studied. Conclusion: PPAR-γ agonists may have antidepressant properties, which need to be assessed in further studies of major depressive episodes.