Does circadian dysrhythmia drive the switch into high‐ or low‐activation states in bipolar I disorder?

Abstract

Objectives: Emerging evidence suggests a role of circadian dysrhythmia in the switch between "activation" states (i.e., objective motor activity and subjective energy) in bipolar I disorder. Methods:We examined the evidence with respect to four relevant questions: (1) Are natural or environmental exposures that can disrupt circadian rhythms also related to the switch into high-/low-activation states? (2) Are circadian dysrhythmias (e.g., altered rest/activity rhythms) associated with the switch into activation states in bipolar disorder? (3) Do interventions that affect the circadian system also affect activation states? (4) Are associations between circadian dysrhythmias and activation states influenced by other "third" factors?Results: Factors that naturally or experimentally alter circadian rhythms (e.g., light exposure) have been shown to relate to activation states; however future studies need to measure circadian rhythms contemporaneously with these natural/experimental factors. Actigraphic measures of circadian dysrhythmias are associated prospectively with the switch into high-or low-activation states, and more studies are needed to establish the most relevant prognostic actigraphy metrics in bipolar disorder.Interventions that can affect the circadian system (e.g., light therapy, lithium) can also reduce the switch into high-/low-activation states. Whether circadian rhythms mediate these clinical effects is an unknown but valuable question. The influence of age, sex, and other confounders on these associations needs to be better characterised. Conclusion:Based on the reviewed evidence, our view is that circadian dysrhythmia is a plausible driver of transitions into high-and low-activation states and deserves prioritisation in research in bipolar disorders.

Early warning signals observed in motor activity preceding mood state change in bipolar disorder

“…50 No differences between euphoric or dysphoric (hypo)manic episodes should be expected, as both conditions are characterized by increased energy. 22 The same group had slightly increased MADRS scores at the start, however, such residual symptoms are commonly observed in euthymic bipolar patients, 51 and should not destructively affect the representativeness of the sample. Apart from these considerations, we evaluate our study to be of substantial and solid quality, as we analyzed a sample of high clinical accuracy, relevance, and consistency, entirely in line with recommendations for studies on complex dynamical systems in bipolar disorder.…”

“…Disturbed circadian rhythmicity has been proposed as the driving force behind the transition to mood state relapse. 22 The association between disrupted circadian rhythmicity and bipolar mood episodes is well-established, 7 entrenched by the strong association between sleep disturbance and mood episodes. 23 However, associations do not necessarily imply causality.…”