RESEARCH ARTICLE The effect of memantine in adult patients with attention deficit hyperactivity disorder Soleiman Mohammadzadeh 1 | Tina Kaveh Ahangari 2 | Fayegh Yousefi 2 1 Child and Adolescent Psychiatrist, Neurosciences Research Center, Kurdistan University of Medical Sciences, Sanandaj, Iran 2 Neurosciences Research Center, Kurdistan University of Medical Sciences, Sanandaj, Iran Correspondence Fayegh Yousefi, Department of Psychiatry, Faculty of Medicine, Kurdistan University of Medical Science, Sanandaj, Iran. Email: f.yousefi@muk.ac.ir Abstract Background: Hyperactivity disorder and attention deficit are common neurological disorders in children and adolescents. The symptoms of hyperactivity are decreased in adults, and attention deficit is more noticeable. This study was carried out to evaluate the effect of memantine on adult patients with attention deficit hyperactivity disorder (ADHD). Materials and methods: In a double‐blind clinical trial study, 40 patients aged 18 to 45 years with ADHD were selected on the basis on the Diagnosis and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM‐IV‐TR) criteria, and randomly assigned memantine or placebo. Before starting the treatment, Conners' screening questionnaire was completed for each patient, and the subjects were entered the study after acquiring minimum acceptable score in the questionnaire. Results: The mean age of patients who were receiving memantine and placebo was about 34.7 ± 4.48 and 31.5 ± 7.4 years, respectively. The results have shown a signif- icant difference in the behavior and attention deficit between the two groups treated with memantine and placebo during 6 weeks (p < 0.001). Also, there was a significant difference in the third and sixth weeks between treatment groups in hyperactivity and attention deficit index (p = 0.001). Conclusion: The results of this study indicated that memantine was effective in reducing symptoms of Inattention/Memory Problems, Hyperactivity/Restlessness, Impulsivity/Emotional Lability. KEYWORDS attention deficit, adult, clinical trial, memantine, hyperactivity 1 | INTRODUCTION Attention deficit hyperactivity disorder (ADHD) is a common neuro- logical disorder in children and adolescents, which occurs as a devel- opmental disorder in 3–5% of children. The disorder is characterized through an inappropriate amount of attention deficit, impulsivity, and aggressiveness, and the possibility of the symptoms to continue and reach the adulthood is by 50–70%. Some researchers have esti- mated the incidence of adolescent ADHD in the range of 2–4% (Sadock, Sadock, & Kaplan, 2009). The estimated ADHD prevalence in Diagnosis and Statistical Manual of Mental Disorders, Fourth Edition (DSM‐IV), in the total sample was by 3.4%, which was significantly higher than the mean in France (7.3%, SE = 1.8), and in Colombia (1.9%, SE = 0.5), Lebanon (1.8%, SE = 0.7), Mexico (1.9%, SE = 0.4), and Spain (1.2%, SE = 0.6; Fayyad et al., 2007). Approximately 90% of adults with ADHDs do not have a history of this disorder during their childhood. Of course, it is estimated that adults with ADHD who have not been tested or assessed for psychi- atric and neuropsychiatric disorders in childhood or adolescence Received: 12 August 2018 Revised: 14 December 2018 Accepted: 18 December 2018 DOI: 10.1002/hup.2687 Hum Psychopharmacol Clin Exp. 2019;34:e2687. https://doi.org/10.1002/hup.2687 © 2019 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/hup 1 of 7