Repurposing of Anti-Diabetic Agents for the Treatment of Cognitive Impairment and Mood Disorders.

Impairments in cognitive function represent a consistent, non-specific, and clinically significant feature in metabolic, mood, and dementing disorders. The foregoing observation is instantiated by evidence demonstrating that these disorders share pathophysiological mechanisms including, but not limited to, aberrant insulin signaling, inflammation, and glucocorticoid activity. Moreover, these mechanisms have been consistently reported to increase vulnerability to and/or exacerbate impairments in cognitive function. Notwithstanding evidence suggesting a bidirectional relationship between disturbances in the metabolic milieu, mood, and increased risk for dementia, efficacious treatments that target cognitive impairments in these populations do not presently exist. Taken together, it is proposed that anti-diabetic agents may aid the management of mood disorders and future risk for dementia through disease modification by targeting underlying pathophysiological mechanisms (e.g., aberrant metabolic function) rather than focusing solely on symptom mitigation. The current aim is to provide a brief narrative review of extant studies that report on the potential neurotherapeutic effects of anti-diabetic agents on disturbances in mood and impairments in cognitive function.

Prevalence of fibromyalgia and co-morbid bipolar disorder: A systematic review and meta-analysis.

BACKGROUND: Fibromyalgia (FM) is a chronic disorder with high morbidity and significant health service utilization costs. Few studies have reported on the phenotypic overlap of FM and bipolar disorder (BD). The aim of this review is to qualitatively and quantitatively summarize the results and clinical implications of the extant literature on the co-occurrence of FM and BD. METHODS: A systematic search of PubMed/Medline, Cochrane, PsycINFO, CINAHL and Embase was conducted to search for relevant articles. Articles were included if incidence and/or prevalence of BD was determined in the FM sample. Results of prevalence were pooled from all studies. Pooled odds ratio (OR) was calculated based on case-control studies using standard meta-analytic methods. RESULTS: A total of nine studies were included. The pooled rate of BD comorbidity in samples of FM patients was 21% (n=678); however, results varied greatly as a function of study methodology. Case-controlled studies revealed a pooled OR of 7.55 of BD co-morbidity in samples of FM patients [95% Confidence Interval (CI)=3.9-14.62, FM n=268, controls n=413] with low heterogeneity (I(2)=0%). LIMITATIONS: The current study was limited by the low number of available studies and heterogeneity of study methods and results. CONCLUSIONS: These data strongly suggest an association between BD and FM. Future studies employing a validated diagnostic screen are needed in order to more accurately determine the prevalence of BD in FM. An adequate psychiatric assessment is recommended in FM patients with suspected symptoms consistent with BD prior to administration of antidepressants in the treatment of FM.

Sleep architecture variation: a mediator of metabolic disturbance in individuals with major depressive disorder.

Remarkable proportions of individuals diagnosed with major depressive disorder (MDD) have comorbid metabolic disturbances (i.e., obesity, type 2 diabetes mellitus (T2DM), hypertension, dyslipidemia), and vice versa. Accumulating evidence suggests that common pathophysiologic pathways such as a chronic, low-grade, proinflammatory state mediate this frequent co-occurrence. However, it remains unclear what traits precede the onset and increase the risk for these pathologic states. The aim of our review was to evaluate the evidentiary base supporting the hypothesis that the increased hazard for metabolic disturbance in MDD subpopulations (and vice versa) is mediated in part by endophenotypic variations in sleep architecture. We conducted a PubMed search of all English-language literature with the following search terms: sleep disturbance, circadian rhythm, inflammation, metabolic syndrome, obesity, MDD, mood disorder, prodrome, T2DM, cytokine, interleukin, hypertension, dyslipidemia, and hypercholesterolemia. Longitudinal and meta-analysis data indicate that specific variations in sleep architecture (i.e., decreased slow-wave sleep [SWS], increased rapid eye movement [REM] density) precede the onset of depressive symptomatology for a subpopulation of individuals. The same sleep architecture variations also are associated with obesity, T2DM, and hypertension. Decreased SWS and increased REM density is correlated with an increase in proinflammatory cytokines (e.g., IL-6, tumor necrosis factor, etc.). This proinflammatory state has been independently shown to be associated with MDD and metabolic disturbances. Taken together, our review suggests that sleep architecture variation of increased REM density and decreased SWS may be an endophenotypic trait, which serves to identify a subpopulation at increased risk for depressive symptoms and metabolic disturbances. Future research is needed to discern the predictive value, sensitivity, and specificity of using sleep architecture variation as a biomarker for MDD and metabolic disturbances. Validation of this marker would have broad clinical implications, such as primary, secondary, and tertiary preventative health strategies.