Comorbid ADHD, Insomnia Associated With Poorer Mental Functioning, Productivity

Co-occurring attention-deficit/hyperactivity disorder (ADHD) and insomnia were associated with poorer mental functioning and lower productivity, per study data published in Psychological Medicine. These results emphasize the importance of screening for sleep problems in patients with ADHD and vice versa.

While prior studies have suggested that treating sleep problems may alleviate ADHD symptoms in adults, the relationship between insomnia and ADHD on general functioning remains unclear. To further assess the relationship between ADHD and insomnia, investigators extracted data from the Netherlands Mental Health Survey and Incidence Study-2, a multistage, prospective, cohort study of adults residing in the Netherlands.

Randomly selected respondents were invited to complete a household interview assessing psychiatric symptoms. Interviews were administered face-to-face by trained study personnel. Baseline surveys were administered between 2007 and 2009, with 2 follow-up waves conducted at 3-year intervals. Surveys captured ADHD symptoms using the Adult ADHD Self-Report Scale (ASRS). Insomnia severity was assessed across 4 domains using a 2-, 3-, 5-, or 6-point Likert scale. Participants were also asked to report their mental functioning, physical functioning, and productivity loss in relation to ADHD and insomnia symptoms. Productivity loss was defined as ever being inhibited in the performance of usual activities. Multiple linear regression was used to assess the impact of ADHD and insomnia on self-reported quality of life and productivity. Models were adjusted for age, sex, education level, employment status, smoking status, body mass index, and physical or mental comorbidities.  

Overall, 4618 participants completed all 3 survey waves. Half (50.2%) of all participants were women, and the cohort was evenly distributed across 4 age brackets: 23 to 37 years (26%); 38 to 47 years (22.7%); 48 to 57 years (24.2%); and 58 to 70 years (27.1%). Total mean baseline ASRS score was 5.5±0.10 out of a possible 24. Total mean insomnia score was 5.5±0.08 out of a possible 20.

In fully adjusted regression models, greater insomnia and ADHD symptom scores predicted poorer physical and mental functioning and greater productivity loss (all P <.001). However, only mental functioning and productivity were significantly affected by the interaction between ADHD symptoms and insomnia (both P <.001). Physical functioning and healthcare utilization were not directly affected by the ADHD × insomnia interaction term. The inattention and hyperactivity domains of ADHD did not appear to have different influences on quality of life and productivity loss. While healthcare utilization was increased with ADHD and insomnia individually, it was not affected by the interaction term.

These results suggest that the combined burden of ADHD and insomnia may play a unique role in mental functioning and productivity, even after adjustment for other psychiatric comorbidities. As study limitations, investigators cited the use of self-reported symptoms rather than clinical diagnoses. However, the scales used by the survey have shown good concordance with clinical diagnoses.

“A better understanding of the relationships between ADHD and various sleep problems can lead to more targeted and effective treatment and may prevent subclinical symptoms from developing into clinical diagnoses,” investigators concluded.

Reference

van Andel E, Ten Have M, Bijlenga D, Beekman ATF, de Graaf R, Sandra Kooij JJ. Combined impact of ADHD and insomnia symptoms on quality of life, productivity, and health care use in the general population [published online June 29, 2020]. Psychol Med. doi: 10.1017/S0033291720001592