Memantine for Executive Dysfunction in Adults With ADHD: A Pilot Study

Inclusion Criteria: 1. Male or female adults ages 18-50 years 2. A diagnosis of childhood onset ADHD, according to the Diagnostic and Statistical Manual of Mental Disorder, Fourth Edition (DSM-IV) based on clinical assessment 3. A score of 20 or more on the Adult ADHD Investigator Symptom Report Scale (AISRS) 4. EFDs as established by at least 2 abnormal (\>65) subscales of BRIEF-A Exclusion Criteria: 1. A history of non-response or intolerance to methylphenidate at adequate doses as determined by the clinician 2. A history of non-response or intolerance to memantine at adequate doses as determined by the clinician 3. Pregnant or nursing females 4. A history of clinically unstable or significant other psychiatric conditions including suicidality, homicidality, bipolar disorder, psychosis, or current tic disorder, as judged by the clinician 5. History of narrow angle glaucoma 6. Current (within 3 months) DSM-IV criteria for substance abuse or dependence 7. Medical condition or treatment that will either jeopardize subject safety or affect the scientific merit of the study, including cardiovascular disease, hypertension, history of renal or hepatic impairment, organic brain disorders, or history of seizure disorder. 8. Abnormal hematological or metabolic parameters 9. IQ \< 80 10. Current use of any psychotropic medication 11. Lack of facility with the English language 12. Investigator and his/her immediate family; defined as the investigator's spouse, parent, child, grandparent, or grandchild