Antidepressants May Prove Effective - with autistic children - Brief Article

USA Today (Society for the Advancement of Education), Oct, 2000

Many autistic children may suffer from a genetically linked depression that is treatable with antidepressants such as Prozac (fluoxetine). According to Robert DeLong, a pediatric neurologist at Duke University Medical Center, Durham, N.C., about two-thirds of youngsters with the most common form of infantile autism actually have a treatable, genetically linked, early-onset form of severe depression.

Children with autism appear to be prisoners of their own minds because they are unable to learn the language or social skills necessary to get along in the world. The condition is a spectrum of disorders with similar symptoms. Those who develop autism, usually in the second year of life, lose the ability to interact with people or their environment and don't speak or use language, even though many have normal intelligence.

While some autism is caused by diseases or injury to certain areas of the developing brain, most cases have no known cause. Of these so-called idiopathic cases, 70% appear to be an inherited form of affective disorder, such as manic depression or obsessive-compulsive disorder. "These children show none of the cheerfulness or spontaneity of normal children. And they often have extreme mood swings, tantrums, and excessive fearfulness."

Several lines of evidence show a distinct subgroup of autistic youngsters who have a genetic disease that can be treated with anti-depressive medications. When researchers examine the brains of children with idiopathic autism, they find very low levels of the neurotransmitter serotonin on the left side of the brain in the area responsible for language. Serotonin is important in influencing mood and is low in people with clinical depression. "In the developing brains of children, serotonin not only acts as a transmitter of information, but it is also an agent of development that influences growth in the brain. When serotonin levels in the left hemisphere of the brain don't reach a critical level in early childhood, one might expect to see the symptoms we see in autism: blunting of the child's cognitive, social, and emotional development."

Serotonin levels in the right hemisphere of most idiopathic autistic children are normal, as are their visual and spatial skills. In fact, some autistic savants show a type of overcompensation on the right side of the brain that gives them extraordinary abilities in math computation, music, or artistic skills. When the researchers studied older children and adolescents diagnosed with manic depression, they discovered greater visual-spatial abilities and lower language skills, although the differences were not as great as in autistic youngsters.

This led DeLong to try treating autistic children with Prozac and other specific serotonin reuptake inhibitors. These medications, well-known for treating depression, work by making more serotonin available to the brain. When 37 autistic children ages three to seven were treated with Prozac for up to three years, 22 responded well to the medication, regaining language abilities, becoming more sociable, and losing obsessive compulsions such as fixating on a single object for hours on end. Of those who responded to the medication, all had a family history of a major depressive disease, such as bipolar disorder.

"It is tempting to say that autism and manic depression are caused by a defect in the same gene," says DeLong, "and genetic evidence is beginning to point in that direction." Studies by him and his colleagues point to a gene somewhere on chromosome 15 as a potential au-tism gene. Meanwhile, investigators at other institutions studying manic depression have narrowed down their search to the same general area on chromosome 15 as well. Such genetic studies offer hope of an earlier diagnosis, and the development of more specific medications to increase the availability of serotonin in the developing brains of autistic children offers the hope of more effective treatment. "Instead of seeing autism as a disease we can't do anything about, we now see it as treatable, rather than hopeless."