Journal of psychiatric research
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Review Meta Analysis
Neuroimaging hippocampal subfields in schizophrenia and bipolar disorder: A systematic review and meta-analysis.
The hippocampus is a complex structure consisting of subregions with specialized cytoarchitecture and functions. Magnetic resonance imaging (MRI) studies in psychotic disorders show hippocampal subfield abnormalities, but affected regions differ between studies. We here present an overview of hippocampal anatomy and function relevant to psychosis, and the first systematic review and meta-analysis of MRI studies of hippocampal subfield morphology in schizophrenia and bipolar disorder. ⋯ In conclusion, the hippocampal subfields appear to be differently affected in psychotic disorders. However, due to the lack of control for putative confounders such as medication, alcohol and illicit substance use, and illness stage, the results from the meta-analysis should be interpreted with caution. Methodological subfield segmentation weaknesses should be addressed in future studies.
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There is increasing recognition that traumatic stress encountered throughout life, including those prior to military service, can put individuals at increased risk for developing Posttraumatic Stress Disorder (PTSD). The purpose of this study was to examine the association of both traumatic stress encountered during deployment, and traumatic stress over one's lifetime on probable PTSD diagnosis. Probable PTSD diagnosis was compared between military personnel deployed in Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF; N = 21,499) and those who have recently enlisted (N = 55,814), using data obtained from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS). ⋯ Similarly, the total quantity of traumatic stress (i.e. cumulative lifetime traumatic stress) did not predict probable PTSD diagnosis among new soldiers. Together, traumatic stress over one's lifetime is a predictor of probable PTSD for veterans, as much as traumatic stress encountered during war. Clinicians treating military personnel with PTSD should be aware of the impact of traumatic stress beyond what occurs during war.
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Childhood trauma has been found to be a critical risk factor for depression in adolescents. Personality traits have been linked with mental health. However, the relationship between childhood trauma, personality traits, and depressive symptoms in adolescents is largely unclear. ⋯ And 'childhood trauma-personality traits-depression' models showed better property than the alternative models of 'childhood trauma-depression-personality traits'. The current study provides preliminary evidence for mediation roles of neuroticism and extraversion in the effect of childhood trauma to depressive symptoms in adolescents. These findings may contribute to better prevention and interventions for depressive symptoms among adolescents with childhood trauma via personality traits improvement.
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The hippocampus has been implicated in various mood disorders, with global volume deficits consistently found in patient populations. The hippocampus, however, consists of anatomically distinct subfields, and examination of specific subfield differences may elucidate the possible molecular mechanisms behind psychiatric pathologies. Indeed, adult studies have reported smaller hippocampal subfield volumes in regions within the cornu ammonis (CA1 and CA4), dentate gyrus (DG), and hippocampal tails in both patients with Major Depressive Disorder (MDD) and Bipolar Disorder (BD) compared to healthy controls. ⋯ Children and adolescents with BD were found to have significantly smaller volumes in the right CA1, CA4, and right subiculum, as well as the bilateral granule cell layer (GCL), molecular layer (ML), and hippocampal tails. The volume of the right subiculum in BD patients was also found to be negatively correlated with illness duration. Overall, the findings from this cross-sectional study provide evidence for specific hippocampal subfield volume differences in children and adolescents with BD compared to healthy controls and suggest progressive reductions with increased illness duration.
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Meta Analysis
Combining genetic and epigenetic parameters of the serotonin transporter gene in obsessive-compulsive disorder.
While genetic variants have been reported to be associated with obsessive-compulsive disorder (OCD), the small effect sizes suggest that epigenetic mechanisms such as DNA methylation may also be relevant. The serotonin transporter (SLC6A4) gene has been extensively investigated in relation to OCD, since serotonin reuptake inhibitors are the pharmacological treatment of choice for the disorder. The current study set three questions: Firstly, whether the high expressing loci of the SLC6A4 polymorphisms, 5-HTTLPR + rs25531, rs25532 and rs16965628 are associated with family-based (n = 164 trios) and case-control OCD (n = 186, 152, respectively). ⋯ Morning awakening salivary cortisol levels positively correlated with methylation levels, and negatively correlated with RNA levels. This study further supports the involvement of the SLC6A4 gene in OCD through both genetic and epigenetic mechanisms. This finding needs to be explored further in an independent large sample.