Associations of pineal volume, chronotype and symptom severity in adults with attention deficit hyperactivity disorder and healthy controls

Abstract

The pineal gland, as part of the human epithalamus, is the main production site of peripheral melatonin, which promotes the modulation of sleep patterns, circadian rhythms and circadian preferences (morningness vs. eveningness). The present study analyses the pineal gland volume (PGV) and its association with circadian preferences and symptom severity in adult ADHD patients compared to healthy controls. PGV was determined manually using high-resolution 3T MRI (T1-magnetization prepared rapid gradient echo) in medication free adult ADHD patients (N=74) compared to healthy controls (N=86). Moreover, the Morningness-Eveningness Questionnaire (MEQ), the ADHD Diagnostic Checklist and the Wender-Utah Rating Scale were conducted. PGV differed between both groups (patients: 59.9±33.8mm(3); healthy controls: 71.4±27.2mm(3), P=0.04). In ADHD patients, more eveningness types were revealed (patients: 29%; healthy controls: 17%; P=0.05) and sum scores of the MEQ were lower (patients: 45.8±11.5; healthy controls 67.2±10.1; P<0.001). Multiple regression analyses indicated a positive correlation of PGV and MEQ scores in ADHD (β=0.856, P=0.003) but not in healthy controls (β=0.054, P=0.688). Patients' MEQ scores (β=-0.473, P=0.003) were negatively correlated to ADHD symptoms. The present results suggest a linkage between the PGV and circadian preference in adults with ADHD and an association of the circadian preference to symptom severity. This may facilitate the development of new chronobiological treatment approaches for the add-on treatment in ADHD.

Sleep disorders in patients with ADHD: impact and management challenges

“…Individuals with ADHD reported increased daytime sleepiness across studies40,47,81,92,106,107 as well as shorter sleep duration82,91,94,97 compared with healthy controls. Finally, having an evening circadian type was more prevalent for individuals with ADHD40,89,92,95 compared with healthy controls.…”

“…Delayed sleep timing and daytime sleepiness were associated with higher levels of reported inattention and hyperactivity in participants with ADHD and DSPD compared with healthy controls 96. Evening chronotype was associated with higher levels of ADHD symptoms 40,89,95…”

“…Greater eveningness was found in individuals with ADHD compared with healthy controls. Eveningness was related to higher severity of the ADHD symptoms 40,95…”

“…Subjective sleep reports both from parents of children with ADHD and adults with ADHD have consistently reported high prevalence of sleep problems 40,47,77,81,86,92,94,95,97,99,101,106,107. Higher level of reported sleepiness was found for individuals with ADHD and OSA77 and individuals with ADHD symptoms and narcolepsy81,106,107 compared with those without ADHD and healthy controls, respectively.…”

A systematic review of circadian function, chronotype and chronotherapy in attention deficit hyperactivity disorder

“…An increase in urinary 6-sulfatoxymelatonin was noted in another study of 27 children and adolescents with ADHD (Büber et al 2016). A potential involvement of pineal function and anatomy in mediating ADHD-related changes in melatonin is suggested by the study of Bumb et al (2016) which reports that ADHD was associated with lower pineal volume in a sample of 74 adults. Further, in a case report Cunniffe et al (2010) report that sleep/wake alterations in an adolescent with a pineal tumour had been masked clinically by the presence of an ADHD diagnosis, thus highlighting the overlap of sleep/wake symptoms resulting from ADHD or pineal dysfunction.…”