Aim of the study:
The aim of present study was to investigate the effect of adding different doses of memantine to methyphenidate in the treatment of children with Attention deficit hyperactivity disorder

Subject or material and methods:
In a double blind clinical trial, 72 patients with ADHD were evaluated. Patients randomly divided into two groups. Group one received lower doses of memantine (0.1-0.25 mg/kg) and Methylphenidate ; group two received higher doses of memantine(0.25-0.5 mg/kg) and Methylphenidate for six weeks . 39 patients who continued the study until the end, at the week zero, second, fourth and sixth, their demographic and clinical information were assessed by demographic questionnaire and Conners Parent Questionnaire.

Results:
The mean score of the primary parents Conners score in the study was 23.84 ± 2.44 and in the sixth week, it was 12.58 ± 2.89 without statistically significant difference at any time of week zero (p <0.275), second (p = 0.921), fourth (p = 0.7) and sixth (p = 0.966)

Discussion:
Memantine was effective in the treatment of patients with hyperactivity disorder, and constantly reduced patients' Conners score over a 6-week period. However, no significant difference was observed between patients receiving higher dose of memantine and patients given lower dose of memantine.

Conclusions:
given the increased risk of the related side effects, it is advisable to prescribe a lower dose of memantine along with methylphenidate.