Autism is a mental condition characterized by difficulties with social interaction and communication. There are several types of autism defined by symptoms present. Autistic disorder involves problems with social interaction, communication, and play from a young age. Asperger's syndrome is similar but does not impact language. The causes of autism are not fully known but genetics are thought to play a role. Symptoms include delays in speech, repetitive behaviors, problems communicating, and difficulty with changes in routine. Prevention efforts include avoiding drugs and alcohol during pregnancy.