A drug normally used to treat schizophrenia has been given approval by the U.S. the Food and Drug Administration for use in treating the symptoms of autism in children and adolescents.

Risperdal, which is made by drug company Johnson & Johnson, is the first drug to be given approval for treating autism.

According to the FDA, Risperdal can be used to treat irritability, aggression, deliberate self-injury and temper tantrums in autistic patients.

Autism spectrum disorders are complex developmental disabilities which usually manifest themselves during the first three years of life and are the result of a neurological disorder that affects the normal functioning of the brain.

The disorders have a profound impact on normal development in the areas of social interaction and communication skills and affect behaviour, learning and leisure or play activities.

Autism conveys a broad range of symptoms, from repetitive, compulsive behaviours to trouble with language and sometimes mental retardation.

Both children and adults with autism have problems with verbal and non-verbal communication, but the condition affects each individual differently and at varying degrees.

Early diagnosis is crucial in order that specialized intervention programmes can be put in place.

There is no cure and treatment commonly consists of behaviour management programmes and often special education.

The FDA granted it’s approval following two eight-week studies on 156 autistic patients most between the ages of 5 and 12, who were given either Risperdal or a placebo.

The FDA says it was found that the children who were treated with Risperdal had improved scores on two scales measuring behavioral symptoms.

According to the Centers for Disease Control and Prevention, autism affects as many as one in every 175 children which equates to at least 300,000 U.S. school children with autism.

Johnson & Johnson says although Risperdal does not treat the core autism symptoms such as communication problems and trouble with social interactions, it has been shown to be beneficial in treating the associated behavioral disturbances that can interfere with school, learning and family life.

Risperdal is an antipsychotic drug which is taken orally and has been on the market since 1993 for the short-term treatment of adults with schizophrenia.

In 2003 it was also approved for the short-term treatment of adults with bipolar mania.

The most common side effects include drowsiness, constipation, fatigue and weight gain.