<prompt> All of the following regarding Autistic spectrum disorder are true exceptDefective communicationAbsent separation anxietyImpaired concentrationMore common in girls  <response>: Ans. is D i.e., More common in girls Autism is more common in boys and among low socio-economic groups. Onset of symptoms of infantile autism usual form of autism is before 2.5 - 3 years. If onset of symptoms is after 3 years, it is referred to as childhood autism. Presently, the cause of infantile autism seems to be predominantly biological.PresentationA. Marked impairment in social interaction: - There is no social smile or eye contact. These children prefer to play alone with inanimate objects and do not like to mingle with others do not make friends. There is lack of attachment to parents and absence of separation anxiety.B. Impairment in communication language as well as non-verbal communication: - Delayed or absence speech, lack of verbal or facial response to sounds or voices, abnormal speech patterns, echolalia, perseveration and prominent reversal referring to self as you and to others as I.C. Stereotyped and restricted repetitive behavior, interests and activities:- Mannerism, Stereotype behavior head banging, body-spinning, rocking, clapping, watching own hand.D. Other features: - Mental retardation in 50-75 patient, epilepsy in 25-35, Hyperkinesis, inability to concentrate. 