Ten medical studies about circadian rhythm and bipolar disorder – a hopeful avenue of research that can lead to better treatment options.
Circadian rhythm is your bodies internal 24 hour clock that regulates your sleep/wake cycle. Each listing includes a quote from the study abstract and a link to the study.
“Patients affected by bipolar disorder (BD) frequently report abnormalities in sleep/wake cycles. In addition, they showed abnormal oscillating melatonin secretion, a key regulator of circadian rhythms and sleep patterns.”
“The acetylserotonin O-methyltransferase (ASMT) is a key enzyme of the melatonin biosynthesis and has recently been associated with psychiatric disorders such as autism spectrum disorders and depression.”
“A convergence of evidence suggests that sleep problems in bipolar disorder result from dysregulation across both process C and process S systems.”
“Biomarkers of depressive episodes include heightened fragmentation of rapid eye movement (REM) sleep, reduced REM latency, increased REM density, and a greater percentage of awakenings, while biomarkers of manic episodes include reduced REM latency, greater percentage of stage I sleep, increased REM density, discontinuous sleep patterns, shortened total sleep time, and a greater time awake in bed.”
“Mood spectrum disorders, including bipolar disorder (BD), major depressive disorder (MDD), and seasonal affective disorder (SAD), have been observed to be accompanied by circadian dysregulation as well as dysregulation in melatonin secretion.”
“Simultaneously, it has also been documented that disruptions in circadian rhythms, including the sleep/wake cycle, though environmental means can produce mood-related problems in vulnerable individuals. These findings suggested that altered circadian rhythms might be biological markers of these disorders.”
“Circulating melatonin is a main synchronizer of the sleep/wake cycle control and human mood and behavior.”
“Exogenous melatonin exerts a therapeutic effect in bipolar patients by normalizing the sleep/wake cycle and may improve both sleep duration and quality and, in addition, recent research has shown that exogenous melatonin can have a marked improvement in affective symptoms.”
“Activity rhythms are highly abnormal in acute phases of BPD; we compared circadian activity rhythms in BPD I patients during ill and recovered states to those of normal controls to test the hypothesis that some abnormalities may persist.”
“While sleep disturbance and circadian dysregulation are critical pathophysiological elements in bipolar disorder, many questions about the mechanisms that underpin the association remain.”
“The author presents a model that recognizes a role for genetic vulnerability and suggests that there is a bidirectional relationship between daytime affect regulation and nighttime sleep such that an escalating vicious circle of disturbance in affect regulation during the day interferes with nighttime sleep/circadian functioning, and the effects of sleep deprivation contribute to difficulty in affect regulation the following day.”
“Animal data based primarily on genetic manipulations and clinical data from biomarker and gene expression studies support the notion that circadian abnormalities underlie certain psychiatric disorders.”
“In particular, bipolar disorder has an interesting link to rhythm-related disease biology; other mood disturbances, such as major depressive disorder, seasonal affective disorder and the agitation and aggression accompanying severe dementia (sundowning), are also linked to changes in circadian rhythm function.”
“Quantitative and qualitative circadian abnormalities are associated with bipolar disorders both during acute episodes and euthymic periods, suggesting that these altered circadian rhythms may represent biological trait markers of the disorder.”
“Relative circadian phase delay (e.g., later melatonin peak, evening chronotype) is associated with BSD, particularly in the depressive phase.”
“More consistent evidence supports irregularity of social rhythms, sleep/wake and activity patterns, and disruptions of social rhythms by life events, as stable trait markers of BSD and potential vulnerabilities for BSD onset.”
“Forty-six patients with BD and 42 controls had comprehensive sleep/circadian rhythm assessment with respiratory sleep studies, prolonged accelerometry over 3 weeks, sleep questionnaires and diaries, melatonin levels, alongside mood, psychosocial functioning and quality of life (QoL) questionnaires.”
“Twenty-three (50%) patients with BD had abnormal sleep, of whom 12 (52%) had CRD and 29% had obstructive sleep apnoea. Patients with abnormal sleep had lower 24-h melatonin secretion compared to controls and patients with normal sleep. Abnormal sleep/CRD in BD was associated with impaired functioning and worse QoL.”
Note: For this last study you do need to request the full transcript from Cambridge University Press.