Group 1 Pimozide 2 mg (current) or 4 mg/day (study initiation) for Amyotrophic Lateral Sclerosis (Pimozide2 Trial)

This study will look at whether Pimozide may help to slow the progression of Amyotrophic Lateral Sclerosis. 100 people from several Canadian centres with ALS who have provided their consent will be randomly assigned into one of 2 groups. The first group will receive a dose of up to 2mg of Pimozide per day and the second group will receive placebo (lactose tablets). Subjects will be assigned randomly (like by a flip of a coin) to receive either Pimozide 2 mg per day or placebo tablets. There will be a fifty-fifty chance of receiving Pimozide or placebo. Participants will be on study medication up to 22 weeks, and on study up to 26 weeks. There are 8 clinic visits and 1 phone visit over the course of the Treatment Phase of the study. The second phase which is Observational, is optional with follow-up for up to 5 years from the end of the Treatment Phase.