Associations of ADHD symptom severity, sleep/circadian factors, depression and quality of life: Secondary analyses of the Netherlands Sleep Registry study

Study objectivesWe investigated whether sleep disruption and circadian preference mediate the associations of ADHD symptom severity with depression symptom severity and quality of life. Methods1364 participants (mean: 51.86 [SD = 0.37] years, 75% females) from a large-scale cross-sectional online survey (Netherlands Sleep Registry) completed a sociodemographic questionnaire, the Adult ADHD Rating Scale, Hospital Anxiety and Depression Scale (HADS), Satisfaction With Life Scale (SLS) and Cantril Ladder (CL) (quality of life measures), Insomnia Severity Index, Pittsburgh Sleep Quality Index, and Munich Chronotype Questionnaire. ResultsHigher ADHD symptom severity was significantly associated with depression severity (p = 0.03), lower quality of life (p < 0.001), insomnia severity (p < 0.001), lower sleep quality (p < 0.001), and later circadian preference (p = 0.01). No sleep or circadian factor significantly mediated the association of the severity of symptoms of ADHD and depression (all p > 0.1). Conversely, only insomnia severity significantly mediated the association of the severity of symptoms of ADHD and quality of life (SLS: standardized beta = -0.10, 95% CI = [-0.12, -0.04]; CL: standardized beta = .103, 95% CI = [0.04, 0.16]). ConclusionADHD symptom severity was associated with lower quality of life, primarily mediated by insomnia symptom severity. Future studies targeting insomnia complaints in this population may help mitigate their depression complaints and improve their quality of life.