A significant subset of both major depressive disorder and bipolar disorder patients rapidly (within 24 hours) and robustly improves with the chronotherapeutic intervention of sleep deprivation ...therapy (SDT). Major mood disorder patients are reported to have abnormal circadian rhythms including temperature, hormonal secretion, mood, and particularly sleep. These rhythms are modulated by the clock gene machinery and its products. It is hypothesized that SDT resets abnormal clock gene machinery, that relapse of depressive symptoms during recovery night sleep reactivates abnormal clock gene machinery, and that supplemental chronotherapies and medications can block relapse and help stabilize circadian-related improvement. The central circadian clock genes, BMAL1/CLOCK (NPAS2), bind to Enhancer Boxes to initiate the transcription of circadian genes, including the period genes ( per1, per2, per3 ). It is suggested that a defect in BMAL1/CLOCK (NPAS2) or in the Enhancer Box binding contributes to altered circadian function associated, in part, with the period genes. The fact that chronotherapies, including SDT and sleep phase advance, are dramatically effective suggests that altered clock gene machinery may represent a core pathophysiological defect in a subset of mood disorder patients.
Abstract Background Conventional antidepressants usually require several weeks to achieve a full clinical response in patients with major depressive disorder (MDD), an illness associated with ...dysregulated circadian rhythms and a high incidence of suicidality. Two rapid-acting antidepressants, low-dose ketamine (KT) and sleep deprivation (SD) therapy, dramatically reduce depressive symptoms within 24 hr in a subset of MDD patients. However, it is unknown whether they exert their actions through shared regulatory mechanisms. To address this question we performed comparative transcriptomics analyses to identify candidate genes and relevant pathways common to KT and SD. Methods We used the forced swim test (FST), a standardized behavioral approach to measure antidepressant-like activity of KT and SD. We investigated gene expression changes using high-density microarrays and pathway analyses (GO, KEGG, GSEA) in KT- and SD-treated mice compared to saline-treated controls. Results We show that KT and SD elicit common transcriptional responses implicating distinct elements of the circadian clock and processes involved in neuronal plasticity. There is an overlap of 64 genes whose expression is common in KT and SD. Specifically, there is down-regulation of clock genes including Ciart, Per2, Npas4, Dbp, and Rorb in both KT and SD treated mice. Conclusions We demonstrate a potential involvement of the circadian clock in rapid antidepressant responses. These findings could open new research avenues to help design chrono-pharmacological strategies to treat major depressive disorder.
A cardinal symptom of major depressive disorder (MDD) is the disruption of circadian patterns. However, to date, there is no direct evidence of circadian clock dysregulation in the brains of patients ...who have MDD. Circadian rhythmicity of gene expression has been observed in animals and peripheral human tissues, but its presence and variability in the human brain were difficult to characterize. Here, we applied time-of-death analysis to gene expression data from high-quality postmortem brains, examining 24-h cyclic patterns in six cortical and limbic regions of 55 subjects with no history of psychiatric or neurological illnesses (“controls”) and 34 patients with MDD. Our dataset covered ∼12,000 transcripts in the dorsolateral prefrontal cortex, anterior cingulate cortex, hippocampus, amygdala, nucleus accumbens, and cerebellum. Several hundred transcripts in each region showed 24-h cyclic patterns in controls, and >100 transcripts exhibited consistent rhythmicity and phase synchrony across regions. Among the top-ranked rhythmic genes were the canonical clock genes BMAL1(ARNTL), PER1-2-3, NR1D1(REV-ERBa), DBP, BHLHE40 (DEC1) , and BHLHE41(DEC2) . The phasing of known circadian genes was consistent with data derived from other diurnal mammals. Cyclic patterns were much weaker in the brains of patients with MDD due to shifted peak timing and potentially disrupted phase relationships between individual circadian genes. This transcriptome-wide analysis of the human brain demonstrates a rhythmic rise and fall of gene expression in regions outside of the suprachiasmatic nucleus in control subjects. The description of its breakdown in MDD suggests potentially important molecular targets for treatment of mood disorders.
A growing number of epidemiological and experimental studies has established that circadian disruption is strongly associated with psychiatric disorders, including major depressive disorder (MDD). ...This association is becoming increasingly relevant considering that modern lifestyles, social zeitgebers (time cues) and genetic variants contribute to disrupting circadian rhythms that may lead to psychiatric disorders. Circadian abnormalities associated with MDD include dysregulated rhythms of sleep, temperature, hormonal secretions, and mood which are modulated by the molecular clock. Rapid-acting antidepressants such as subanesthetic ketamine and sleep deprivation therapy can improve symptoms within 24 h in a subset of depressed patients, in striking contrast to conventional treatments, which generally require weeks for a full clinical response. Importantly, animal data show that sleep deprivation and ketamine have overlapping effects on clock gene expression. Furthermore, emerging data implicate the circadian system as a critical component involved in rapid antidepressant responses via several intracellular signaling pathways such as GSK3β, mTOR, MAPK, and NOTCH to initiate synaptic plasticity. Future research on the relationship between depression and the circadian clock may contribute to the development of novel therapeutic strategies for depression-like symptoms. In this review we summarize recent evidence describing: (1) how the circadian clock is implicated in depression, (2) how clock genes may contribute to fast-acting antidepressants, and (3) the mechanistic links between the clock genes driving circadian rhythms and neuroplasticity.
Substance Use Disorder (SUD) is a major public health concern affecting an estimated 22.5 million individuals in the United States. The primary aim of this study was to characterize psychological ...pain in a cohort of patients participating in outpatient treatment for SUD. A secondary aim was to determine the relationships between pre-treatment assessments of psychological pain, depression, anxiety and hopelessness with treatment retention time and completion rates. Data was analyzed from 289 patients enrolled in an outpatient community drug treatment clinic in Southern California, U.S. A previously determined threshold score on the Mee-Bunney Psychological Pain Assessment Scale (MBP) was utilized to group patients into high and low-moderate scoring subgroups. The higher pain group scored higher on measures of anxiety, hopelessness and depression compared to those in the low-moderate pain group. Additionally, patients scoring in the higher psychological pain group exhibited reduced retention times in treatment and more than two-fold increased odds of dropout relative to patients with lower pre-treatment levels of psychological pain. Among all assessments, the correlation between psychological pain and treatment retention time was strongest. To our knowledge, this is the first study to demonstrate that psychological pain is an important construct which correlates with relevant clinical outcomes in SUD. Furthermore, pre-treatment screening for psychological pain may help target higher-risk patients for clinical interventions aimed at improving treatment retention and completion rates.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Psychological pain is a relatively understudied and potentially important construct in the evaluation of suicidal risk. Psychological pain also referred to as 'mental pain' or 'psychache' can be ...defined as an adverse emotional reaction to a severe trauma (e.g., the loss of a child) or may be associated with an illness such as depression. When psychological pain levels reach intolerable levels, some individuals may view suicide as the only and final means of escape. To better understand psychological pain, we previously developed and validated a brief self-rating 10-item scale, Mee-Bunney Psychological Pain Assessment Scale MBP in depressed patients and non-psychiatric controls. Our results showed a significant increase in psychological pain in the depressed patients compared to controls. We also observed a significant linear correlation between psychological pain and suicidality in the depressed patient cohort. The current investigation extends our study of psychological pain to a diagnostically heterogeneous population of 57 US Veterans enrolled in a suicide prevention program. In addition to the MBP, we administered the Columbia Suicide Severity Rating Scale (C-SSRS), Beck Depression Inventory (BDI-II), Beck Hopelessness Scale (BHS), and the Barratt Impulsiveness Scale (BIS-11). Suicidal patients scoring above a predetermined threshold for high psychological pain also had significantly elevated scores on all the other assessments. Among all of the evaluations, psychological pain accounted for the most shared variance for suicidality (C-SSRS). Stepwise regression analyses showed that impulsiveness (BIS) and psychological pain (MBP) contributed more to suicidality than any of the other combined assessments. We followed patients for 15 months and identified a subgroup (24/57) with serious suicide events. Within this subgroup, 29% (7/24) had a serious suicidal event (determined by the lethality subscale of the C-SSRS), including one completed suicide. Our results build upon our earlier findings and recent literature supporting psychological pain as a potentially important construct. Systematically evaluating psychological pain along with additional measures of suicidality could improve risk assessment and more effectively guide clinical resource allocation toward prevention.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Psychiatric disorders are multigenic diseases with complex etiology that contribute significantly to human morbidity and mortality. Although clinically distinct, several disorders share many ...symptoms, suggesting common underlying molecular changes exist that may implicate important regulators of pathogenesis and provide new therapeutic targets.
We performed RNA sequencing on tissue from the anterior cingulate cortex, dorsolateral prefrontal cortex, and nucleus accumbens from three groups of 24 patients each diagnosed with schizophrenia, bipolar disorder, or major depressive disorder, and from 24 control subjects. We identified differentially expressed genes and validated the results in an independent cohort. Anterior cingulate cortex samples were also subjected to metabolomic analysis. ChIP-seq data were used to characterize binding of the transcription factor EGR1.
We compared molecular signatures across the three brain regions and disorders in the transcriptomes of post-mortem human brain samples. The most significant disease-related differences were in the anterior cingulate cortex of schizophrenia samples compared to controls. Transcriptional changes were assessed in an independent cohort, revealing the transcription factor EGR1 as significantly down-regulated in both cohorts and as a potential regulator of broader transcription changes observed in schizophrenia patients. Additionally, broad down-regulation of genes specific to neurons and concordant up-regulation of genes specific to astrocytes was observed in schizophrenia and bipolar disorder patients relative to controls. Metabolomic profiling identified disruption of GABA levels in schizophrenia patients.
We provide a comprehensive post-mortem transcriptome profile of three psychiatric disorders across three brain regions. We highlight a high-confidence set of independently validated genes differentially expressed between schizophrenia and control patients in the anterior cingulate cortex and integrate transcriptional changes with untargeted metabolite profiling.
Current antidepressants are ineffective in many depressed patients. Thus there is an urgent need to develop treatment strategies which have significantly faster response, can be sustained and have ...minimal side-effects. This paper reviews clinical data, potential biomarkers, mechanisms of action and future research directions for two proven strategies that produce marked improvement in severe depressive symptoms within 48 h, ketamine and sleep deprivation therapy (SDT). These treatments provide unequivocal evidence that the depressive process can be rapidly reversed in a subgroup of patients. Seventeen ketamine studies in over 150 patients showed a rapid response. Low-dose intravenous ketamine produced mild psychotomimetic effects but response has not been effectively sustained. SDT has been investigated in over 60 studies with a 40–60% response rate within 48 h. Although SDT is often used in Europe to initiate a rapid response, it is less utilized within the USA, in part, because it has a short duration when administered alone. We review data concerning chronotherapeutic strategies of bright-light therapy (BLT) and sleep-phase advance (SPA) which successfully sustain the antidepressant efficacy of SDT. Evidence is further discussed that a significant group of mood disorders have abnormal circadian rhythms which are known to be controlled by clock genes. It is hypothesized that chronotherapeutic manipulations can reset clock genes and thus, abnormalities in circadian rhythms. Further findings are reviewed that ketamine, in addition to its role as an NMDA antagonist, can also alter circadian rhythms. Thus, ketamine may share a critical mechanism with SDT.
Major mood disorders have been linked to abnormalities in circadian rhythms, leading to disturbances in sleep, mood, temperature, and hormonal levels. We provide evidence that ketamine, a drug with ...rapid antidepressant effects, influences the function of the circadian molecular machinery. Ketamine modulates CLOCK:BMAL1-mediated transcriptional activation when these regulators are ectopically expressed in NG108-15 neuronal cells. Inhibition occurs in a dose-dependent manner and is attenuated after treatment with the GSK3β antagonist SB21673. We analyzed the effect of ketamine on circadian gene expression and observed a dose-dependent reduction in the amplitude of circadian transcription of the Bmal1, Per2, and Cry1 genes. Finally, chromatin-immunoprecipitation analyses revealed that ketamine altered the recruitment of the CLOCK:BMAL1 complex on circadian promoters in a time-dependent manner. Our results reveal a yet unsuspected molecular mode of action of ketamine and thereby may suggest possible pharmacological antidepressant strategies.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Suicides have increased to over 48,000 deaths yearly in the United States. Major depressive disorder (MDD) is the most common diagnosis among suicides, and identifying those at the highest risk for ...suicide is a pressing challenge. The objective of this study is to identify changes in gene expression associated with suicide in brain and blood for the development of biomarkers for suicide. Blood and brain were available for 45 subjects (53 blood samples and 69 dorsolateral prefrontal cortex (DLPFC) samples in total). Samples were collected from MDD patients who died by suicide (MDD-S), MDDs who died by other means (MDD-NS) and non-psychiatric controls. We analyzed gene expression using RNA and the NanoString platform. In blood, we identified 14 genes which significantly differentiated MDD-S versus MDD-NS. The top six genes differentially expressed in blood were: PER3, MTPAP, SLC25A26, CD19, SOX9, and GAR1. Additionally, four genes showed significant changes in brain and blood between MDD-S and MDD-NS; SOX9 was decreased and PER3 was increased in MDD-S in both tissues, while CD19 and TERF1 were increased in blood but decreased in DLPFC. To our knowledge, this is the first study to analyze matched blood and brain samples in a well-defined population of MDDs demonstrating significant differences in gene expression associated with completed suicide. Our results strongly suggest that blood gene expression is highly informative to understand molecular changes in suicide. Developing a suicide biomarker signature in blood could help health care professionals to identify subjects at high risk for suicide.
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