At the screening visit, investigators will perform a full history-taking, mental status examination, physical and neurological examinations, the ADI-R with a caregiver or parent to confirm autism, an EKG and complete rating scales, as well as a pregnancy test (beta-HCG) in sexually active females of childbearing age. Sexually active females of childbearing age must be on a form of birth control during the study, such as the oral contraceptive pill, intrauterine device or Depo Provera shot. A parent or guardian will sign informed consent, as appropriate, and written assent will be obtained from subjects. Blood tests for CBC and diff, CMP, amitriptyline level will be obtained at at baseline (except for amitriptyline) week 6 and 12. An eye-tracking test will be done at baseline and week 12.~Subjects will be randomized to amitriptyline (AMI) or placebo. Parents and guardians will be instructed to lock up all medications, warned regarding overdose toxicity and this will be documented in writing. Treatment will be low dose AMI or placebo for 12 weeks. Study visits will occur at weeks 0,1, 2, 3, 4, 5, 6, 8,10, and 12.~Investigators will complete a Clinical Global Impressions scale (CGI), and have the accompanying adult or parent complete rating scales, at each visit, notably the Child Yale Brown Obsessive Compulsive scale modified for Pervasive Developmental Disorder (CYBOCS-PDD), Aberrant Behavior Checklist-Irritability subscale (ABC-I), Repetitive Behavior Scale-Revised (RBS-R), ADHD-RS, adverse events form, ADI-R item 11 for phrase speech, and a concomitant treatment review form, which will also detail for example any over-the-counter medications, supplements or antibiotics taken. Also a gastrointestinal symptom form based on that used by Valicenti-McDermott et al. 2008.~At all interim visits, the PI will perform a follow-up history taking, mental status examination, vital signs, rating scales as above and study drug dispensing. Any unused capsules must be returned at each visit, to monitor compliance as well as to prevent accidental overdose. Parents and caregivers will agree to lock medication up, and will be reminded of overdose toxicity at each study visit, with written documentation.~Flexible dosing, arranged by calling the pharmacy to randomize the subject and then dispense and mail study capsules, according to the psychiatrist's instructions at each visit, to a maximum dose of 100mg/day or 1.5mg/kg/day maximum by subject weight.~Individuals and their parents or guardians will be questioned about suicidal ideation at each visit, and instructed to call study staff if that should arise. At that time the PI will arrange an urgent visit to closely assess risks of remaining in the study. In our experience suicidal ideation has not occurred. Subjects may drop out at any time however, and in the unlikely case, if warranted, be admitted to hospital for close observation.~The study will be double- blind and placebo-controlled. All investigators except a child psychiatrist co-investigator will be blinded, as will caregivers, families and subjects.
The investigators will recruit 30 children and adolescents (15 per group x 2 groups) aged 6 to 17 years with ASD and significant repetitive behaviors that cause problems to them and to others around them. Subjects will be randomized to either amitriptyline (AMI), dosed flexibly according to response and tolerability with a maximum dose of 100mg per day or 1.5mg/kg/day, in divided doses to minimize side effects, or placebo in look-alike capsules, for 12 weeks. Rating scales, and eye-tracking will be used to measure outcomes.