Attention-Deficit/Hyperactivity Disorder Patients May Have Undiagnosed Narcolepsy

Lukas Wilenius; Markku Partinen

doi:10.7759/cureus.8436

Attention-Deficit/Hyperactivity Disorder Patients May Have Undiagnosed Narcolepsy

Cureus. 2020 Jun 4;12(6):e8436. doi: 10.7759/cureus.8436.

Authors

Lukas Wilenius¹, Markku Partinen^{2

3}

Affiliations

¹ Neurology, University of Helsinki, Helsinki, FIN.
² Helsinki Sleep Clinic, Vitalmed Research Center, Helsinki, FIN.
³ Clinical Neurosciences, University of Helsinki, Helsinki, FIN.

Abstract

Background Attention-deficit/hyperactivity disorder (ADHD) patients have many comorbidities. Narcoleptic patients have a big prevalence of ADHD (15%-30%). Both groups suffer from similar symptoms and benefit from the same class of medications. As such, narcolepsy could be masked in ADHD patients. Low serum ferritin has been found both in ADHD patients as well as in patients with narcolepsy. Materials & methods We enrolled 26 participants (14 ADHD patients and 12 controls). They answered several questionnaires, and blood samples were obtained from 20 participants. We had clear exclusion criteria. Results Using the Ullanlinna Narcolepsy Scale (UNS), we identified three possible narcolepsy patients within the ADHD group and no suspects in the control group. There was a statistically significant negative correlation between serum iron levels and ADHD symptom severity. No correlation was found measuring serum ferritin levels. Conclusions Narcolepsy may be more common within ADHD patients than in the general population. Some of these patients could benefit from a change in medication. Low serum iron and ferritin levels could be relevant in ADHD pathophysiology. This requires further exploratory research.

Keywords: adult adhd; attention deficit hyperactivity disorder (adhd); cataplexy; excessive daytime sleepiness; narcolepsy; serum ferritin; serum iron.

Grants and funding

I received payments from Finska Läkaresällskapet and Stiftelsen Dorothea Olivia, Karl Walter och Jarl Walter Perkléns minne to cover the running fees and the personal time spent on doing this study.