Pervasive Development Disorder Characteristics
Pervasive development disorder (PDD), also known as autism spectrum disorder (ASD), is a neurological condition primarily defined by delays in socialization and communication abilities. This disorder often becomes apparent when a child is between one and three years old and parents realize that his or her social and communication skills do not seem to be developing normally.
PDD affects an estimated 1 to 2 out of 500 children, and is more prevalent in boys, affecting four to five times as many boys as girls. While there is a broad range of symptoms that differ depending on the individual, some of the characteristics of PDD include:
- Limited communication skills, including using and understanding language
- Difficulty understanding non-verbal communication
- Impaired ability to socialize
- Unusual manner of playing with toys or objects
- Difficulty accepting change in daily routine or surroundings
- Limited interests and activities
- Repetitive movements or behaviors
- Unusual responses to sounds
- Anxiety or fearfulness
Pervasive developmental disorder differs from specific developmental disorders in that it involves delays in a broad range of skills, where specific developmental disorders are limited to delays in certain areas such as motor skills or learning.
The Main Types of Pervasive Development Disorders
There are five main types of pervasive development disorders.
Autism- The characteristics of autism include difficulty with communication, social interaction and ability to pretend, repetitive behaviors, and a narrow range of interests and activities. About three-quarters of children with autism also have some degree of mental retardation.
Asperger’s Syndrome- This disorder has many similarities to autism. Symptoms of Asperger’s syndrome include impaired communication and social skills and limited interests, but intelligence is usually average or above average, and language development is normal. Other symptoms include poor concentration and a lack of bodily coordination.
Rett’s Syndrome- This is a rare condition that primarily strikes girls because it is associated with a defect on the X chromosome. Characteristics of Rett’s syndrome include the same social and communication difficulties that are seen in the other PDDs, with the addition of loss of motor skills.
Childhood Disintegrative Disorder- Another rare disorder, children who suffer from childhood disintegrative disorder develop normally at first, and do not begin to show symptoms until they are between the ages of two and ten. At the onset of the disorder, the child begins to lose language and social skills, and may also lose the ability to control bodily functions such as bladder and bowel movements.
Pervasive Development Disorder Not Otherwise Specified (PDDNOS)- This condition has symptoms similar to those of autism, such as lack of communication and social skills and repetitive movements, but children with PPDNOS cannot be diagnosed with autism because they do not satisfy all of the conditions.
Many of the same pervasive development disorder characteristics are shared by these different types of the condition.