Do you experience sleep disturbances during the winter months? If you do, there is a good chance that those disturbances come from seasonal depression. A study published in the Journal of Psychiatric Research explores the differing patterns and profiles of these sleep disturbances in hopes to improve future treatments.
Seasonal depression is a type of mood disturbance associated with a certain time of year, typically winter. Due to the low light of winter in many places, treatments such as light therapy are utilized for seasonal depression, in addition to more traditional treatment methods, such as cognitive-behavioral therapy (CBT) and psychotropic medication.
Sleep and circadian rhythms are thought to play a key role in seasonal depression, but they are heterogenous and present in different ways, which would require varying treatments. This study seeks to better understand the differing patterns and typologies of sleep disturbance associated with seasonal depression, in order to aid in future interventions and treatments.
In the study, Delainey L. Wescott of the University of Pittsburgh and colleagues utilized 103 participants aged 18-65 who were recruited through a research registry in Pittsburgh, Pennsylvania. All data was collected during the winter months, between December 21st and March 21st. Participants completed a clinical interview that assessed seasonal depression and other DSM-5 diagnoses, as well as change in mood, behavior, appetite, sleep, energy, weight, and social behaviors across different seasons.
Participants completed a biomarker measure of circadian phase in a laboratory setting for a six-hour period. Participants wore a watch that measured actigraphy data, including sleep onset, total sleep time, sleep efficiency, and sleep midpoint, wake after sleep onset, and more, for 5 to 14 days. Lastly, participants completed sleep diaries for 5 to 14 days.
Results showed that there were multiple identifiable patterns and profiles of sleep and circadian disturbance. This included a ‘disrupted sleep’ cluster and an ‘advanced’ cluster. The former consisted of irregular, fragmented, less efficient sleep, and the latter was characterized by longer, earlier sleep and circadian timing.
Though different clusters were identified, these varying profiles were not significantly different on the severity of the depression or the diagnoses. These different clusters have implications for treatment and intervention.
This research suggests that the ‘disrupted sleep’ group may benefit from CBT-I to stabilize sleep, while the ‘advanced’ cluster could respond better to behavioral activation such that they are socializing instead of settling early.
This study took significant steps into better understanding differing profiles of sleep disturbances associated with seasonal depression, which has implications for treatment. Despite this, there are limitations to note. One such limitation is that the study accepted 5 days and up for the actigraphic measures, but there is previous research saying that the measure is not as valid or reliable when used for less than 7 nights.
Additionally, the sample size was on the small end for a cluster analysis; future research could expand on this study by utilizing a larger and more diverse sample.
“Treating sleep and circadian disruptions in seasonal depression may benefit from an individually-tailored, precision medicine approach,” the researchers concluded. “Changing the perspective of sleep and circadian disruptions in seasonal depression from uniformly hypersomnia and phase delay to a more accurate heterogenous presentation will be more effective when identifying the most promising interventions. Identifying the key drivers of sleep-related pathophysiology in seasonal depression may minimize time to remission and reduce recurrence rates.”
“Replication of the current findings is critical. While the current study focused on seasonal depression, sleep and circadian disruptions are transdiagnostic. Targeting specific sleep-wake and biological rhythm profiles could aid our understanding of the etiology of mood dysregulation if tested prospectively.”
The study, “Sleep and circadian rhythm profiles in seasonal depression“, was authored by Delainey L. Wescott, Meredith L. Wallace, Brant P. Hasler, Alison M. Klevens, Peter L. Franzen, Martica H. Hall, and Kathryn A. Roecklein.
