Delayed sleep phase cases and controls

Abstract

Background: Delayed sleep phase disorder (DSPD) is a condition in which patients have difficulty falling asleep before the early morning hours and commonly have trouble awakening before late morning or even early afternoon. Several studies have suggested that variations in habitual bedtime are 40-50% heritable.

The etiology of delayed sleep phase disorder

“…Though only a few studies have investigated the impact of DSPD on health [17], results suggest that depression, as well as the use of medication (esp. antacids and hypnotics), tobacco, alcohol and caffeine is greater in patients than controls [18,19]. DSPD patients report less sport participation in school [19], as well as social difficulties and daytime sleepiness.…”

Delayed sleep phase disorder risk is associated with absenteeism and impaired functioning

“…To increase the probability that respondents were at risk for DSPD 17 and based on the age-related increase in morningness tendency, 27 all those aged 18-55 years who selected that they were "definitely an evening type" and all those aged 56-65 years who selected that they were either "more an evening than a morning type" or definitely an evening type were classified as evening type and were invited to complete the survey.…”

“…19 DSPD patients show higher current depression ratings, antidepressant use, and greater lifetime history of unipolar depression compared to controls. 17,20 For example, 41% of DSPD sleep clinic patients showed evidence of depression; 7.2% showed moderate to severe depression. 21 The absence of a questionnaire screening tool for DSPD remains a barrier to the detection of those with DSPD symptoms and to the investigation of its prevalence, etiology, pathophysiology, and clinical significance.…”

“…Adolescents with delayed bedtimes show poorer school performance, more disciplinary issues, and increased irritability and depression. 3,17 Adults with delayed sleep report impaired job performance, financial difficulties, marital problems, 14 and the ongoing use of sedatives and hypnotic drugs, behavioral interventions, or psychotherapy. 18 The comorbidity of DSPD and mood disorders has been described, 14,19 with depression being the most common.…”

“…19 DSPD patients show higher current depression ratings, antidepressant use, and greater lifetime history of unipolar depression compared to controls. 17,20 For example, 41% of DSPD sleep clinic patients showed evidence of depression; 7.2% showed moderate to severe depression. 21…”