Autistic Spectrum Disorders (ASD) are a group of developmental disorders including autistic disorder, Asperger disorder and pervasive developmental disorder not otherwise specified which may be treated by use of a galanthamine analog wherein the hydroxy group of galantamine is replaced by a carbamate, carbonate or ester group and the methoxy group may be replaced by another alkoxy group of from two to six carbon atoms, a hydroxy group, hydrogen, an alkanoyloxy group or 2 to 10 carbon atoms, a benzoyloxy or substituted benzoyloxy group, a carbonate group of 1 to 10 carbon atoms or a carbamate group such as a mono alkyl or dialkyl or an aryl carbamate wherein the alkyl groups or aryl groups contain from 1 to 10 carbons; and the N-methyl group may be replaced by hydrogen, alkyl of 1 to 10 carbon atoms, benzyl, cyclopropylmethyl group or a substituted or unsubstituted benzoyloxy group. Galantamine mon-alkylcarbamates are particularly useful.