Dark skies before the storm: The Chronos syndrome

Dear Editor, Bipolar disorders recently published an intriguing study indicating that 6.1% of individuals with subthreshold manic symptoms progressed to a full-blown hypomanic or manic episode during a 3-year follow-up.1 The study also identified 11 risk factors associated with this unfavorable course, with the most significant ones being a history of depression or dysthymia, living without a partner, and an elevated neuroticism score.1 This new study adds to the extensive international research conducted to better understand these risk syndromes and prodromes of a mood episode.2 The objective of these studies was to intervene as early as possible and prevent a full-blown mood episode and its consequences.2 However, intervening at the right moment during the prodromal phase is not straightforward. Identifying a clinical syndrome that reliably predicts an imminent transition to a mood episode seems meaningful. Recent data, especially research on sleep, circadian rhythms, and dream content,3, 4 indicate strong predictive elements for a transition to a full-blown mood episode. In Greek mythology, Chronos personifies time and possesses the power to control and travel through time, thus predicting the future. The "Chronos syndrome" in mood disorders could thus be a prodromal syndrome of an imminent progression toward the tipping point with a disruption of global functioning, characteristic of a full-blown depressive, or manic episode (Figure 1). Interestingly, the idea of these premorbid states that could predict the future in an individual's life date back to Antiquity. Aristotle was one of the first to apply this idea to the medical field, suggesting that dreams could reveal the sleeper's first signs of changes in the body, imperceptible during wakefulness. Current neuroscientific and clinical research confirms the predictive value of sleep, circadian, and dream alterations before a mood episode.3, 4 Patients seem capable of identifying these prodromes, with probable interindividual variability in clinical manifestations, meaning that the specific symptoms may differ among individuals.5 There is also evidence of some intraindividual recurrence in the case of multiple mood episodes, suggesting that similar manifestations may reoccur in the same individual across different episodes.5 Identifying and examining this Chronos syndrome in each individual could enable earlier and more effective personalized prodromal intervention. By targeting the proximal prodromal phase predictive of imminent progression, healthcare professionals can attempt to stop or delay the progression of the disorder, offering individuals the best chance for functional remission or symptom reduction. It can also be used as an excellent means of psychoeducation and developing prevention strategies. Identifying the Chronos syndrome could, for example, lead to concrete actions such as co-constructing action plans with healthcare professionals in the event of recurrence. In conclusion, addressing the "Chronos syndrome" during the prodromal phase could lead to more effective interventions, akin to anticipating dark skies before the storm, with the potential to limit or stop the progression to a full-blown mood disorder while empowering psychoeducation and prevention strategies. The author has no conflicts of interest related to this work.