Chronotype and sleep in patients with depression: a case-control study
Chronotype; Sleep; Depression; mental health; circadian rhythms
The circadian rhythm is closely linked to the sleep regulation process (sleep/wake), which has demonstrated a bidirectional relationship with several diseases, including depression. Evening chronotype, a behavioral manifestation of the circadian timing system, has been shown to be a risk factor for the development of psychiatric disorders. Furthermore, sleep problems are observed in the clinical histories of depressive patients. However, in psychiatric clinical practice, little emphasis is given to diagnostic and therapeutic approaches related to chronobiological aspects. Furthermore, it is important that these relationships be investigated in different clinical settings and populations. Thus, the objective of this cross-sectional study was to investigate the chronotype and sleep in patients diagnosed with depression (MD) (n= 16, 11 women) compared with healthy subjects (CTR) (n= 29, 17 women), treated at HUPAA/UFAL and in the CAPS of Maceió, AL. The patients were residents of the city of Maceió, Alagoas, and were assisted in the research settings: Psychiatry Ambulatory of the University Hospital Dr. Alberto Antunes (HUPAA/UFAL), at CAPS Dr Rostan Silvestre, and CAPS Noraci Pedrosa. To assess the diagnosis of depression, the “Mini International Neuropsychiatric Interview” (M.I.N.I - brief structured diagnostic interview for the main psychiatric disorders) was used. To assess the intensity of depressive symptoms, the “Beck Depression Inventory (BDI) was used. To determine the chronotype, the Horne-Ostberg Test (HO) and the Munich Chronotype Questionnaire (MCTQ) were used, which was also used to determine sleep parameters. To assess sleep quality, the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESP) were used. The results showed that patients have worse body mass index (BMI) (p=0.01) when compared with CTR. The HO/MEQ (p= 0.01) and MSFsc scores in hours (p= 0.01) were significantly lower in the MD group, indicating eveningness in this group. There was a significant association between MD and worse sleep quality (p=0.001) compared to CTR. Depressed patients Patients with depression may experience greater weekday sleep inertia (SIW) (p=0.04), having greater difficulty waking up and feeling alert compared to healthy individuals in the control group and and taking longer to leave out of bed during the week (p= 0.02) and on days off (p = 0.01). There was a positive correlation between the Pittsburgh (sleep quality) and BDI (severity of depression) scores, indicating that as sleep quality worsens, depression symptoms tend to intensify (p=0.05). Circadian dysregulations and poor sleep quality have already been considered precursors to mood disorders in previous studies, as well as depression has been considered a risk factor for poor sleep. Likewise, nutritional problems and afternoon chronotype are factors with a greater risk of being present in samples with depression. In the clinic, it is essential to research the chronotype and sleep quality of patients with depression so that professional care guidelines can be implemented, as well as care and preventive conduct in the general population.