What are the Different Types of Autism and Developmental Disorders?

Autism and developmental disorders are neurobiological illnesses commonly grouped under the classification of autism spectrum disorder. Children with this affliction display a wide variety of impairment in their communication and social skills, ranging from mild to severe. The American Psychiatric Society recognizes five basic categories of autism and developmental disorders: autistic disorder, Asperger’s syndrome, Rett syndrome, pervasive developmental disorder-not otherwise specified (PDD-NOS), and childhood disintegrative disorder.

Parents are usually the first ones to notice signs of autism and developmental disorders in their children. These children may exhibit repetitive body movements such as flapping their hands or rocking. Any change in familiar surroundings or routine may cause children within the autism spectrum to throw tantrums and demonstrate an inability to adjust. Children with autism and developmental disorders may have trouble communicating and socializing, since they aren’t able to read body language or interpret and respond to social cues.

Autistic disorder is diagnosed when a child exhibits at least six characteristics from a list of 12 that fall into the following three categories: behavior, communication, and social interaction. Children with this disorder show little interest in interacting with others, and have trouble establishing and/or maintaining relationships. They have a tendency to focus on one thing, and exhibit unusual behaviors while appearing to shut out the rest of the world.

Asperger’s syndrome is a mild form of autism which is often referred to as high functioning autism. The Asperger’s child will exhibit many of the characteristics of autistic disorder, but will usually experience normal intellectual and language development. In contrast with the autistic child, a youngster with Asperger’s will often show an interest in establishing friendships and desire to join in activities with others.

Rett syndrome is a rare genetic disorder that affects only girls. It is the only illness on the autism spectrum that is known to have a genetic component. Girls with this disorder usually don’t develop verbal skills, and many never learn to walk. Small hands, small heads, and chronic gastrointestinal disturbances are common symptoms of this disorder.

PDD-NOS is diagnosed when a child has some of the characteristics of autism, but not enough to warrant an autism diagnosis. The impaired communication skills typical of PDD-NOS often manifest shortly after birth. A baby with this affliction won’t babble like a normal infant and will experience delayed speech development. When verbal communication does begin, the child will usually have a limited vocabulary. He or she typically will exhibit literal thinking and won’t be able to understand joking, sarcasm, or abstract concepts.

When childhood disintegrative disorder is present, the child displays normal development for the first few years but then begins to regress. For example, a child who is potty-trained may lose the ability to control bowel and bladder functions and never regain it. The child may lose social, communication, and motor skills which previously had developed normally. A cause for childhood disintegrative disorder is unknown.