A method for treating an autism spectrum condition includes administering an effective dose of a TNF-α inhibiting agent to a person having an autism spectrum condition or pervasive development disorder and at least one of elevated TNF-α in the cerebrospinal fluid or elevated TNF-α in the serum, as compared to normal conditions and lowering at least one of the elevated TNF-α in the cerebrospinal fluid or elevated TNF-α in the serum. A TNF-α inhibiting agent includes at least one of Lenalinomide Thalidomide L-Carnosine Infliximab Etanercept a stem cell preparation derivatives thereof, isomers thereof, or pharmaceutically acceptable salts thereof.
