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Background: The genetics of depression has been explored in genome-wide association studies that focused on either major depressive disorder or depressive symptoms with mostly negative findings. A broad depression phenotype including both phenotypes has not been tested previously using a genome-wide association approach. We aimed to identify genetic polymorphisms significantly associated with a broad phenotype from depressive symptoms to major depressive disorder., Methods: We analyzed two prior studies of 70,017 participants of European ancestry from general and clinical populations in the discovery stage. We performed a replication meta-analysis of 28,328 participants. Single nucleotide polymorphism (SNP)-based heritability and genetic correlations were calculated using linkage disequilibrium score regression. Discovery and replication analyses were performed using a p-value-based meta-analysis. Lifetime major depressive disorder and depressive symptom scores were used as the outcome measures., Results: The SNP-based heritability of major depressive disorder was 0.21 (SE = 0.02), the SNP-based heritability of depressive symptoms was 0.04 (SE = 0.01), and their genetic correlation was 1.001 (SE = 0.2). We found one genome-wide significant locus related to the broad depression phenotype (rs9825823, chromosome 3: 61,082,153, p = 8.2 × 10 -9 ) located in an intron of the FHIT gene. We replicated this SNP in independent samples (p = .02) and the overall meta-analysis of the discovery and replication cohorts (1.0 × 10 -9 )., Conclusions: This large study identified a new locus for depression. Our results support a continuum between depressive symptoms and major depressive disorder. A phenotypically more inclusive approach may help to achieve the large sample sizes needed to detect susceptibility loci for depression., (Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: Treatment adherence is a significant problem in patients with bipolar disorder. This study was designed to determine the efficacy of risperidone long-acting injectable (LAI) in the maintenance treatment of bipolar I disorder., Methods: Eligible patients with current or recent manic or mixed episodes (n = 559, aged 18-65 years) were treated with open-label oral risperidone for 3 weeks (period II) and open-label risperidone LAI for 26 weeks (n = 501; period III). Patients who maintained response (n = 303) were randomly allocated 1:1 to placebo injections (n = 149) or to continue risperidone LAI (n = 154) for up to 24 months (period IV)., Results: Most (77%) patients on risperidone LAI received a dose of 25 mg every 2 weeks during period IV. Time to recurrence for any mood episode (primary outcome variable) was significantly longer in the risperidone LAI group versus placebo (p < .001); the difference was significant for time to recurrence of elevated-mood episode (p < .001) but not time to recurrence of depressive episode (p = .805). Weight gains > or = 7% (compared with the period's baseline) occurred in 15% of patients in period III; in 12% of patients on risperidone LAI and 3% of patients on placebo in period IV., Conclusions: Risperidone LAI monotherapy significantly delayed the time to recurrence of mood episodes, versus placebo, in this controlled, randomized study in patients with bipolar I disorder. Risperidone LAI was tolerable and no new safety concerns emerged compared with previous studies of risperidone LAI., (Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: Preclinical and clinical evidence indicate that the glutamatergic system might play a role in the pathophysiology of mood disorders. This study was conducted to determine the efficacy and safety of riluzole, a glutamate-modulating agent, in bipolar depression., Methods: This was an 8-week add-on study of riluzole in combination with lithium in acutely depressed bipolar patients aged 18 years and older. After open treatment with lithium for a minimum period of 4 weeks, subjects who continued to have a Montgomery-Asberg Depression Rating Scale (MADRS) score of >/=20 received riluzole (50-200 mg/day) for 8 weeks., Results: Fourteen bipolar depressed patients entered the study. The linear mixed models for total MADRS score showed a significant treatment effect. No switch into hypomania or mania was observed. Overall, riluzole was well tolerated., Conclusions: Although preliminary, these results suggest that riluzole might indeed have antidepressant efficacy in subjects with bipolar depression.

Background: The original serotonergic and noradrenergic hypotheses do not fully account for the neurobiology of depression or mechanism of action of effective antidepressants. Research implicates a potential role of the dopaminergic system in the pathophysiology of bipolar disorder. The current study was undertaken as a proof of the concept that dopamine agonists will be effective in patients with bipolar II depression., Methods: In a double-blind, placebo-controlled study, 21 patients with DSM-IV bipolar II disorder, depressive phase on therapeutic levels of lithium or valproate were randomly assigned to treatment with pramipexole (n = 10) or placebo (n = 11) for 6 weeks. Primary efficacy was assessed by the Montgomery-Asberg Depression Rating Scale., Results: All subjects except for one in each group completed the study. The analysis of variance for total Montgomery-Asberg Depression Rating Scale scores showed a significant treatment effect. A therapeutic response (>50% decrease in Montgomery-Asberg Depression Rating Scale from baseline) occurred in 60% of patients taking pramipexole and 9% taking placebo (p =.02). One subject on pramipexole and two on placebo developed hypomanic symptoms., Conclusions: The dopamine agonist pramipexole was found to have significant antidepressant effects in patients with bipolar II depression.

There is growing evidence from neuroimaging and ostmortem studies that severe mood disorders, which have traditionally been conceptualized as neurochemical disorders, are associated with impairments of structural plasticity and cellular resilience. It is thus noteworthy that recent preclinical studies have shown that critical molecules in neurotrophic signaling cascades (most notably cyclic adenosine monophosphate [cAMP] response element binding protein, brain-derived neurotrophic factor, bcl-2, and mitogen activated protein [MAP] kinases) are long-term targets for antidepressant agents and antidepressant potentiating modalities. This suggests that effective treatments provide both trophic and neurochemical support, which serves to enhance and maintainnormal synaptic connectivity, thereby allowing the chemical signal to reinstate the optimal functioning of critical circuits necessary for normal affective functioning. For many refractory patients, drugs mimicking "traditional" strategies, which directly or indirectly alter monoaminergic levels, may be of limited benefit. Newer "plasticity enhancing" strategies that may have utility in the treatment of refractory depression include N-methyl-D-aspartate antagonists, alpha-amino-3-hydroxy-5-methylisoxazole propionate (AMPA) potentiators, cAMP phosphodiesterase inhibitors, and glucocorticoid receptor antagonists. Small-molecule agents that regulate the activity f growth factors, MAP kinases cascades, and the bcl-2 family of proteins are also promising future avenues. The development of novel, nonaminergic-based therapeutics holds much promise for improved treatment of severe, refractory mood disorders., (Copyright 2003 Society of Biological Psychiatry)

The mechanisms by which sleep deprivation brings about rapid antidepressant effects remain to be elucidated. Biological rhythms have the capacity to temporally dissociate biochemical processes, and imposing a temporal coincidence on normally dissociated events can have striking and unexpected effects. In this context, it is noteworthy that the locus coeruleus (LC) noradrenergic projection is quiescent only during rapid-eye-movement (REM) sleep, when the target tissues display their greatest sensitivity; indeed, the temporal dissociation between the firing of the LC noradrenergic neurons and the sensitivity of its postsynaptic targets in the cortex may have considerable relevance for the antidepressant effects of sleep deprivation. Sleep deprivation rapidly upregulates several plasticity-related genes, effects that are noradrenergically mediated; these are the very same genes that are upregulated by chronic antidepressants. Thus, activating the norepinephrine system during REM sleep (by infusing an alpha(2) antagonist) may allow an interaction with a primed, sensitized postsynaptic milieu, thereby rapidly increasing the expression of plasticity genes and consequently a rapid antidepressant response.