Cabello-Arreola, Alejandra

AbstractINTRODUCTIONResting‐state functional magnetic resonance imaging (fMRI) graph theory may help detect subtle functional connectivity changes affecting memory prior to impairment.METHODSCognitively normal apolipoprotein E (APOE) ε4 carriers/noncarriers underwent longitudinal cognitive assessment and one‐time MRI. The relationship of left/right hippocampal connectivity and memory trajectory were compared between carriers/noncarriers.RESULTSSteepness of verbal memory decline correlated with decreased connectivity in the left hippocampus, only among APOE ε4 carriers. Right hippocampal metrics were not correlated with memory and there were no significant correlations in the noncarriers. Verbal memory decline correlated with left hippocampal volume loss for both carriers and noncarriers, with no other significant volumetric findings.DISCUSSIONFindings support early hippocampal dysfunction in intact carriers, the AD disconnection hypothesis, and left hippocampal dysfunction earlier than the right. Combining lateralized graph theoretical metrics with a sensitive measure of memory trajectory allowed for detection of early‐stage changes in APOE ε4 carriers before symptoms of mild cognitive impairment are present.Highlights Graph theory connectivity detects preclinical hippocampal changes in APOE ε4 carriers. The AD disconnection hypothesis was supported in unimpaired APOE ε4 carriers. Hippocampal dysfunction starts asymmetrically on the left.

Objectives: Prior studies demonstrate elevated cortical glutamate (Glu) in patients with bipolar disorder (BD). Studies assessing neurochemistry in early stages of bipolar illness before the emergence of manic symptoms are lacking. This study aimed to examine neurochemical correlates measured by proton magnetic resonance spectroscopy ( 1 H-MRS) and a dimensional measure of bipolarity in a sample of depressed adolescents. Methods: Adolescent participants (aged 13–21 years) underwent a semistructured diagnostic interview and clinical assessment, which included the General Behavior Inventory Parent Version (P-GBI), a 73-item, parent-rated assessment of symptoms and behaviors. 1 H-MRS scans of a left dorsolateral prefrontal cortex (L-DLPFC) voxel (8 cm 3 ) were collected using a two-dimensional J -averaged sequence to assess N -acetylaspartate (NAA), Glu, Glx (glutamate + glutamine), and NAA/Glx concentrations. We used generalized linear models to assess the relationships between P-GBI scores and metabolite levels in L-DLPFC. Results: Thirty-six participants (17 healthy controls, 19 depressed) underwent 1 H-MRS scans and clinical evaluation with the P-GBI. There was a significant negative relationship between P-GBI score and L-DLPFC NAA/Glx in the whole sample. However, the magnitude of the effect was small and statistical significance was lost after correcting for multiple comparisons. Conclusions: These preliminary results suggest that NAA/Glx may have utility as a marker of bipolar traits in healthy and depressed adolescents. If replicated, 1 H-MRS measures of glutamatergic metabolism anomalies might have a role in identifying depressed adolescents at risk for mixed symptom presentations or BD. Identifying bipolarity in the early stages of the disease would have a significant impact on treatment planning and prognosis. Further longitudinal studies should examine neurochemical correlates of mood state during the developmental emergence of BD.

Suicide is a major public health concern; nevertheless, its neurobiology remains unknown. An area of interest in suicide research is the dorsolateral prefrontal cortex (DLPFC). We aimed to identify altered proteins and potential biological pathways in the DLPFC of individuals who died by suicide employing mass spectrometry-based untargeted proteomics. Postmortem DLPFC from age-matched male suicide mood disorder cases (n = 5) and non-suicide mood disorder cases (n = 5) were compared. The proteins that differed between groups at false discovery rate (FDR) adjusted p-values (Benjamini–Hochberg–Yekutieli) <0.3 and Log2 fold change (FC) >|0.4| were considered statistically significant and were subjected to pathway analysis by Qiagen Ingenuity software. Thirty-three of the 5162 detected proteins showed significantly altered expression levels in the suicide cases and two of them after adjustment for body mass index. The top differentially expressed protein was potassium voltage-gated channel subfamily Q member 3 (KCNQ3) (Log2FC = −0.481, p = 2.10 × 10−09, FDR = 5.93 × 10−06), which also showed a trend to downregulation in Western blot (p = 0.045, Bonferroni adjusted p = 0.090). The most notably enriched pathway was the GABA receptor signaling pathway (p < 0.001). Here, we report a reduction trend of KCNQ3 levels in the DLPFC of male suicide victims with mood disorders. Further studies with a larger sample size and equal sex representation are needed.

Abstract Objective The aim of this study was to evaluate the efficacy and safety of the dopaminergic‐enhancing agent modafinil/armodafinil (MoArm) as adjunctive treatment for bipolar depression. Methods A comprehensive search of major electronic databases was conducted to identify randomized controlled trials (RCTs) of adjunctive MoArm that included patients with bipolar I (BP‐I) or bipolar II (BP‐II) depression. Data for response/remission and all‐cause discontinuation were analyzed. Effect size was summarized by relative risk (RR) using a random effect model. Results Of 58 studies, five RCTs (N = 795 drug, N = 792 placebo) met inclusion criteria. Four armodafinil studies included only BP‐I patients and one modafinil study included both bipolar subtypes with limited heterogeneity ( I 2 = 34%, P = .19; I 2 = 18%, P = .30). Compared to placebo, augmentation with MoArm was associated with significantly greater rates of treatment response (RR, 1.18; 95% CI, 1.01‐1.37; P = .03) and remission (RR, 1.38; 95% CI, 1.10‐1.73; P = .005). All‐cause discontinuation was not different than placebo (RR, 1.08; 95% CI, 0.89‐1.30; P = .45) with no evidence of increased risk of mood switch or suicide attempts with MoArm (RR, 0.99; 95% CI, 0.39‐2.5; P = .98; RR, 1.02; 95% CI, 0.37‐2.85; P = .97). Conclusion This narrower scope meta‐analysis of one drug for one disease suggests that adjunctive MoArm may represent a novel therapeutic intervention. Further studies delineating the subtypes of bipolar depression responsive to these novel dopaminergic‐enhancing agents are encouraged.