Adult ADHD: 6 studies of nonpharmacologic interventions

6. van Andel E, Bijlenga D, Vogel SWN, et al. Effects of chronotherapy on circadian rhythm and ADHD symptoms in adults with attention-deficit/hyperactivity disorder and delayed sleep phase syndrome: a randomized clinical trial. Chronobiol Int. 2021;38(2):260-269. doi:10.1080/07420528.2020.1835943

Most individuals with ADHD have a delayed circadian rhythm.²¹ Delayed sleep phase syndrome (DSPS) is diagnosed when a persistently delayed circadian rhythm is not brought on by other diseases or medications. ADHD symptoms and circadian rhythm may both benefit from DSPS treatment. A 3-armed randomized clinical parallel-group trial by van Andel et al¹³ investigated the effects of chronotherapy on ADHD symptoms and circadian rhythm.

Study design

• Participants were Dutch-speaking individuals age 18 to 55 who were diagnosed with ADHD and DSPS. They were randomized to receive melatonin 0.5 mg/d (n = 17), placebo (n = 17), or melatonin 0.5 mg/d plus 30 minutes of timed morning bright light therapy (BLT) (n = 15) daily for 3 weeks. There were no significant differences in baseline characteristics between groups except that the melatonin plus BLT group had higher use of oral contraceptives (P = .007).
• This study was completed in the Netherlands with participants from an outpatient adult ADHD clinic.
• Exclusion criteria included epilepsy, psychotic disorders, anxiety or depression requiring acute treatment, alcohol intake >15 units/week in women or >21 units/week in men, ADHD medications, medications affecting sleep, use of drugs, mental retardation, amnestic disorder, dementia, cognitive dysfunction, crossed >2 time zones in the 2 weeks prior to the study, shift work within the previous month, having children disturbing sleep, glaucoma, retinopathy, having BLT within the previous month, pregnancy, lactation, or trying to conceive.
• The study consisted of 3-armed placebo-controlled parallel groups in which 2 were double-blind (melatonin group and placebo group).
• During the first week of treatment, medication was taken 3 hours before dim-light melatonin onset (DLMO) and later advanced to 4 and 5 hours in Week 2 and Week 3, respectively. BLT was used at 20 cm from the eyes for 30 minutes every morning between 7 am and 8 am.
• The primary outcome was DLMO in which radioimmunoassay was used to determine melatonin concentrations. DLMO was used as a marker for internal circadian rhythm.
• The secondary outcome was ADHD symptoms using the Dutch version of the ADHD Rating Scale-IV.
• Evaluations were conducted at baseline (T0), the conclusion of treatment (T1), and 2 weeks after the end of treatment (T2).

Outcomes

• Out of 51 participants, 2 dropped out of the melatonin plus BLT group before baseline, and 3 dropped out of the placebo group before T1.
• At baseline, the average DLMO was 11:43 pm ± 1 hour and 46 minutes, with 77% of participants experiencing DLMO after 11 pm. Melatonin advanced DLMO by 1 hour and 28 minutes (P = .001) and melatonin plus BLT had an advance of 1 hour and 58 minutes (P < .001). DLMO was unaffected by placebo.
• The melatonin group experienced a 14% reduction in ADHD symptoms (P = .038); the placebo and melatonin plus BLT groups did not experience a reduction.
• DLMO and ADHD symptoms returned to baseline 2 weeks after therapy ended.

Conclusions/limitations

• In patients with DSPS and ADHD, low-dose melatonin can improve internal circadian rhythm and decrease ADHD symptoms.
• Melatonin plus BLT was not effective in improving ADHD symptoms or advancing DLMO.
• Limitations: This study used self-reported measures for ADHD symptoms. The generalizability of the findings is limited because the exclusion criteria led to minimal comorbidity. The sample was comprised of a mostly Dutch population.