From the Journals

Longer circadian rhythms linked to severe depression in teens



Longer circadian periods and irregular sleep were significantly associated with mental health problems in adolescents including depression, anxiety, suicidality, social anxiety, and panic disorder, according to results from a European study.

A range of psychiatric symptoms and conditions has been linked to sleep pathologies, wrote Liisa Kuula, PhD, of the University of Helsinki, Finland, and colleagues. Some research suggests that late circadian rhythms and irregular sleep patterns increase the risk for psychiatric conditions, but the association has not been well studied, especially in adolescents, although the onset of psychiatric problems often occurs at this age, they said.

Dr. Liisa Kuula, University of Helsinki, Finland

Dr. Liisa Kuula

In a study published in the Journal of Psychiatric Research (2022 Apr 4. doi: 10.1016/j.jpsychires.2022.03.056.), the investigators reviewed data from 342 adolescents who were part of SleepHelsinki! a large cohort study of delayed sleep phase disorder (DSPD) in adolescents. The mean age of the participants was 17.4 years, and 70% were female.

The participants completed the Mini International Neuropsychiatric Interview (MINI) and wore temperature loggers for 3 days to assess circadian rhythms. The primary outcome was the impact of circadian dynamics on different psychiatric problems. Delayed Sleep Phase (DSP) behavior was defined as going to sleep later than 1 a.m. at least three times a week.

Circadian length was determined through the temperature loggers worn for 3 days. Most participants also completed 1-week GeneActiv Original actigraphy measurements (wearing the actigraph for 1 week) and responded to the Morningness-Eveningness Questionnaire, which divided participants into three circadian preference groups: morning, intermediate, and evening. Sleep duration was calculated as total sleep time, sleep quality was estimated by sleep efficiency, and sleep timing was assessed by the midpoint of the sleep period.

Overall, the MINI interview results suggested that approximately one-third (36%) of the teens had at least one psychiatric problem, and 21% had comorbid conditions.

Severe depression was significantly associated with a longer circadian period (P = .002), while suicidality was significantly associated with a later midpoint and more irregular sleep (P = .007 for both).

Participants with agoraphobia slept longer than did those without, the researchers noted (P = .013). However, sleep duration was not significantly associated with other psychiatric conditions.

Manic episodes and psychotic disorders were associated with irregular sleep timing (P < .018 and P < .017, respectively).

When the researchers examined DSP and circadian preferences, they found that 21.5% of individuals with suicidality had characteristics of DSP, as did 21.5% of those with panic disorder.

Individuals with a preference for eveningness were significantly more likely to meet criteria for severe depression, panic disorder, generalized anxiety disorder, and obsessive-compulsive disorder than were those without a preference for eveningness, the researchers noted.

“Our findings are the first to encompass diverse circadian measures alongside an array of psychiatric symptoms in such a focused age range,” the researchers wrote in their discussion. The data reflect results from other studies and extend the likely role of circadian patterns in mental wellbeing, they said.

The study findings were limited by several factors including the lack of actual diagnoses from medical records and use of self-reported symptoms, the researchers noted. Other limitations included the lack of polysomnography data and small size of subgroups of the study sample.

However, the results were strengthened by the heterogenous study population and use of multiple measures to examine sleep and circadian rhythms, as well as consideration of personal circadian preferences, the researchers said.

“The importance of overall synchronization with environment is perhaps best highlighted by response to treatment: most psychopathologic symptoms benefit from sleep-targeted therapeutic approaches,” they concluded.

The study received no outside funding. The researchers had no financial conflicts to disclose.

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