This review (1971) of 7 studies looked at the effect of psychedelics in autistic children (n=91). Psychedelics led to improved speech and mood, better emotional responsiveness, and decreased compulsive behaviour.
“Seven independent studies are reviewed involving 91 autistic children given psychedelic drugs for therapeutic and/or experimental purposes. The majority of children were between six and ten years of age and had failed to respond to other forms of treatment. The most consistent effects of psychedelic therapy reported in these studies included: (a) improved speech behavior in otherwise mute patients; (b) greater emotional responsiveness to other children and adults; (c) increased positive mood including frequent laughter; and (d) decreases in compulsive ritualistic behavior. Differences in patient attributes, treatment technique, and other nondrug factors effected the frequency and stability of favorable outcomes. The kinds of improvements found were essentially the same in each study. The collective results argue strongly for more extensive use of psychedelic drugs in the treatment of autistic children.”
Authors: Robert E. Mogar & Robert W. Aldrich