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Background: Bipolar disorder (BD) is characterized by episodes of depression and mania and disrupted circadian rhythms. Lithium is an effective therapy for BD, but only 30%–40% of patients are fully responsive. Preclinical models show that lithium alters circadian rhythms. However, it is unknown if the circadian rhythm effects of lithium are essential to its therapeutic properties. Methods: In secondary analyses of a multi‐center, prospective, trial of lithium for BD, we examined the relationship between circadian rhythms and therapeutic response to lithium. Using standardized instruments, we measured morningness, diurnal changes in mood, sleep, and energy (circadian rhythm disturbances) in a cross‐sectional study of 386 BD subjects with varying lithium exposure histories. Next, we tracked symptoms of depression and mania prospectively over 12 weeks in a subset of 88 BD patients initiating treatment with lithium. Total, circadian, and affective mood symptoms were scored separately and analyzed. Results: Subjects with no prior lithium exposure had the most circadian disruption, while patients stable on lithium monotherapy had the least. Patients who were stable on lithium with another drug or unstable on lithium showed intermediate levels of disruption. Treatment with lithium for 12 weeks yielded significant reductions in total and affective depression symptoms. Lithium responders (Li‐Rs) showed improvement in circadian symptoms of depression, but non‐responders did not. There was no difference between Li‐Rs and nonresponders in affective, circadian, or total symptoms of mania. Conclusions: Exposure to lithium is associated with reduced circadian disruption. Lithium response at 12 weeks was selectively associated with the reduction of circadian depressive symptoms. We conclude that stabilization of circadian rhythms may be an important feature of lithium's therapeutic effects. Clinical Trials Registry: NCT0127253. [ABSTRACT FROM AUTHOR]

Aim: Symptoms of bipolar disorder (BD) include changes in mood, activity, energy, sleep, and appetite. Since many of these processes are regulated by circadian function, circadian rhythm disturbance has been examined as a biological feature underlying BD. The International Society for Bipolar Disorders Chronobiology Task Force (CTF) was commissioned to review evidence for neurobiological and behavioral mechanisms pertinent to BD. Method: Drawing upon expertise in animal models, biomarkers, physiology, and behavior, CTF analyzed the relevant cross‐disciplinary literature to precisely frame the discussion around circadian rhythm disruption in BD, highlight key findings, and for the first time integrate findings across levels of analysis to develop an internally consistent, coherent theoretical framework. Results: Evidence from multiple sources implicates the circadian system in mood regulation, with corresponding associations with BD diagnoses and mood‐related traits reported across genetic, cellular, physiological, and behavioral domains. However, circadian disruption does not appear to be specific to BD and is present across a variety of high‐risk, prodromal, and syndromic psychiatric disorders. Substantial variability and ambiguity among the definitions, concepts and assumptions underlying the research have limited replication and the emergence of consensus findings. Conclusions: Future research in circadian rhythms and its role in BD is warranted. Well‐powered studies that carefully define associations between BD‐related and chronobiologically‐related constructs, and integrate across levels of analysis will be most illuminating. [ABSTRACT FROM AUTHOR]

Objective: The narrow therapeutic window of lithium medications necessitates frequent serum monitoring, which can be expensive and inconvenient for the patient. Compared to blood, saliva collection is easier, non‐invasive, requires less processing, and can be done without the need for trained personnel. This study investigated the utility of longitudinal salivary lithium level monitoring. Methods: We measured salivary lithium levels using ICP‐OES in n = 169 passive drool samples, collected both as single observations and longitudinally for up to 18 months, from a multi‐center cohort of n = 75 patients with bipolar disorder or other psychiatric conditions. Results: Saliva and serum lithium levels were highly correlated. Adjustment for daily lithium dose, diabetes, and smoking improved this relationship (r = 0.77). Using the adjusted intersubject equation and a patient's salivary lithium value, we observed a strong correlation between the predicted vs. observed serum lithium levels (r = 0.70). Most patients had highly stable saliva/serum ratios across multiple visits, with longitudinal variability significantly greater with age. Use of the intrasubject saliva/serum ratio from a single prior observation had similar predictive power to the use of the adjusted intersubject equation. However, the use of the mean intrasubject ratio from three prior observations could robustly predict serum lithium levels (predicted vs. observed r = 0.90). Conclusions: These findings strongly suggest that saliva could be used for lithium monitoring, and open the door for the development and implementation of a point‐of‐care salivary lithium device for use at home or the clinic. We propose that the use of saliva will dramatically improve treatment opportunities for patients with mood disorders. [ABSTRACT FROM AUTHOR]

Bipolar disorder (BD) is a complex neuropsychiatric disorder characterized by recurrent mania and depression episodes and requiring lifelong treatment with mood stabilizing drugs. Several lines of evidence, including with BD patient iPSC‐derived neurons, suggest that neuronal hyperexcitability may underlie the key clinical symptoms of BD. Indeed, higher mRNA levels of SCN11A, coding for the voltage‐gated sodium channel NaV1.9 implicated in nociception, were detected in iPSC‐derived neurons from BD patients, and were normalized by in vitro lithium. Here we studied SCN11A expression in peripheral blood mononuclear cells (PBMCs) from well‐phenotyped female BD patients and controls and evaluated their association with several clinical sub‐phenotypes. We observed higher mRNA levels of SCN11A in PBMCs from female BD patients with no records of alcohol dependence (p =.0050), no records of psychosis (p =.0097), or no records of suicide attempts (p =.0409). A trend was observed for higher SCN11A expression (FD = 1.91; p =.052) in BD PBMCs compared with controls. Datamining of published postmortem gene expression datasets indicated higher SCN11A expression in dorsolateral prefrontal cortex and orbitofrontal cortex tissues from BD patients compared with controls. Higher phenotype‐associated expression levels in PBMC from BD patients were also observed for ID2 (alcohol dependence, suicide attempts) and HDGFRP3 (seasonal BD pattern). Our findings suggest that higher PBMC SCN11A expression levels may be associated with certain behavioral BD sub‐phenotypes, including lack of alcohol dependence and psychosis, among BD patients. The NaV1.9 voltage‐gated sodium channel thus deserves consideration as a tentative phenotype modifier in BD. [ABSTRACT FROM AUTHOR]

Bipolar disorder (BD) is characterized by severe mood symptoms, often accompanied by circadian rhythm disturbances. Preclinical studies indicate that lithium, a first-line treatment for BD, has effects on circadian rhythms.1 However, less attention has been given to the effects of lithium on the clinical symptoms of BD related to circadian rhythm disruption. We present a case of a BD patient with profound disruption in sleep/wake activity and show that lithium potently corrected her circadian rhythm disturbances. [Extracted from the article]

Circadian clocks are temporal interfaces that organize biological systems and behavior to dynamic external environments. Components of the molecular clock are expressed throughout the brain and are centrally poised to play an important role in brain function. This paper focuses on key issues concerning the relationship among circadian clocks, brain function, and development, and discusses three topic areas: (1) sleep and its relationship to the circadian system; (2) systems development and psychopathology (spanning the prenatal period through late life); and (3) circadian factors and their application to neuropsychiatric disorders. We also explore circadian genetics and psychopathology and the selective pressures on the evolution of clocks. Last, a lively debate is presented on whether circadian factors are central to mood disorders. Emerging from research on circadian rhythms is a model of the interaction among genes, sleep, and the environment that converges on the circadian clock to influence susceptibility to developing psychopathology. This model may lend insight into effective treatments for mood disorders and inform development of new interventions. [ABSTRACT FROM AUTHOR]