Overview
This study is a 12-week randomized-controlled trial of memantine hydrochloride (Namenda) for the treatment of social impairment in youth with Non-Verbal Learning Disorder, High-Functioning Autism Spectrum Disorder, and related conditions. Eligible participants will be males and females ages 8-18.
This study consists of up to 6 visits to Massachusetts General Hospital.
Eligibility
Inclusion Criteria:
- Male & female subjects ages 8-18 years (inclusive).
- Diagnostic Statistical Manual (DSM)-5 Autism Spectrum Disorder (ASD) diagnostic criteria as established by clinical diagnostic interview
- At least moderate severity of social impairment as measured by a total raw score of ≥85 on the parent/guardian-completed Social Responsiveness Scale-Second Edition (SRS-2)14 and a score of ≥4 on the clinician-administered Clinical Global Impression-Severity scale (CGI-S)17.
Exclusion Criteria:
- IQ ≤70 based on the Wechsler Abbreviated Scale of Intelligence-II (WASI-II) Vocabulary and Matrix Reasoning subtests
- Impaired communicative speech
- Subjects currently treated with the following medications (known to impact glutamate levels): Lamotrigine, Amantadine, N-acetylcysteine, D-cycloserine
- Subjects treated with a psychotropic medication not listed above on a dose that has not been stable for at least 4 weeks prior to study baseline.
- Co-administration of drugs that compete with memantine for renal elimination using the same renal cationic system, including hydrochlorothiazide, triamterene, metformin, cimetidine, ranitidine, quinidine, and nicotine
- Initiation of a new psychosocial intervention within 30 days prior to randomization.
- Subjects who are pregnant and/or nursing.
- Subjects with a history of non-febrile seizures without a clear and resolved etiology.
- Subjects with a history of or a current liver or kidney disease.
- Clinically unstable psychiatric conditions or judged to be at serious suicidal risk.
- Subjects who meet on the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS-E) for alcohol or drug dependence or abuse. If the subject has a recent history of substance abuse, there will be a two-week washout period before initiating the trial as an added precaution. There are no known safety issues relating to memantine and recent history of substance abuse.
- Serious, stable or unstable systemic illness including hepatic, renal, gastroenterological, respiratory, cardiovascular (including ischemic heart disease), endocrinologic, neurologic, immunologic, or hematologic disease.
- Subjects with severe hepatic impairment (LFTs > 3 times ULN).
- Subjects with genitourinary conditions that raise urine pH (e.g., renal tubular acidosis, severe infection of the urinary tract).
- Known hypersensitivity to memantine.
- Severe allergies or multiple adverse drug reactions.
- A history of intolerance or adequate exposure to memantine, as determined by the clinician.
- Investigator and his/her immediate family defined as the investigator's spouse, parent, child, grandparent, or grandchild.