The primary objective of the study is to assess the efficacy and tolerability of a 12-week
trial of memantine hydrochloride administered twice daily in 20 adults (ages 18-55) with
ADHD and ADHD NOS. Improvement will be defined as: 1) changes from baseline on the
investigator-rated DSM-IV based ADHD Rating Scale; 2) changes from baseline in a
questionnaire aimed at assessing executive functions (BRIEF); and 3) changes from screening
in a computerized neuropsychological battery (CANTAB). We hypothesize that memantine
hydrochloride will be associated with improving ADHD symptoms and associated deficits in
executive functions. We also expect that memantine will be well-tolerated with predictable
Memantine (Namenda) is a low-affinity N-methyl-D-aspartate (NMDA) receptor antagonist
believed to work by blocking prolonged low-level activation of the NMDA receptor and
resultant neuronal damage caused by abnormal glutamatergic activity, yet also allowing
normal physiological activity of the NMDA channel. Memantine (Namenda) was approved by the
U.S. Food and Drug Administration in 2003 for the treatment of moderate to severe
Alzheimer's disease. Memantine improves or delays the decline in cognition (attention,
language, visuo-spatial ability), as well as functional and behavioral symptoms in adults
with moderate Alzheimer's disease.
Although the efficacy and safety of memantine has not been tested in people with ADHD, the
spectrum of disorders possibly amenable to NMDA receptor antagonist treatment may include
ADHD and associated EFDs. Given its safety profile, and potential efficacy in cognition,
memantine could offer therapeutic benefits for adults with ADHD. To this end, we are
proposing an open-label pilot study of memantine in adult subjects with ADHD and ADHD Not
Otherwise Specified (NOS) (late onset).
This will be a 12-week, open-label pilot study to assess the efficacy and tolerability of
memantine hydrochloride (Namenda) administered to 20 adults 18-55 years of age with ADHD and
ADHD NOS. All subjects that enter the study will undergo standard screening and diagnostic
procedures. After obtaining written informed consent from the subject, the diagnosis of ADHD
will be established through clinical evaluation by an expert clinician. Only consenting
subjects satisfying inclusion and exclusion criteria will be included in the study.
1. Male and female outpatients 18-55 years of age
2. Subjects with the diagnosis of Attention Deficit Hyperactivity Disorder (ADHD), by
DSM-IV or ADHD NOS (late onset; >7 years), as manifested in clinical evaluation and
confirmed by structured interview.
3. Subjects must score at least 14 on inattentive symptom questions on the DSM-IV based
ADHD Rating Scale.
4. Subjects who have an ADHD specific CGI Severity score of 4 or more (> moderately
1. Subjects with a medical condition or treatment that will either jeopardize subject
safety or affect the scientific merit of the study, including:
2. History of Renal or Hepatic Impairment.
3. Organic brain disorders.
4. History of Seizure disorder.
5. Any clinically unstable psychiatric conditions including the following: psychosis,
suicidality, bipolar disorder, current substance use disorders (alcohol or drugs) or
current tic disorder.
6. Mental retardation (IQ <75).
7. Pregnant or nursing females.
8. Known hypersensitivity to memantine.
9. Any current psychotropic treatment, with the exception of stable regimen of SSRIs.