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pervasive developmental disorder Alternative Names
PDD
Definition
Pervasive developmental disorder, or PDD, is a set of complex disorders that affect the brain. PDDs are characterised by an intense difficulty in social interaction and communication with others.
What is going on in the body?
PDD is a neurological disorder that affects the brain. It appears to affect the way a person reacts and interacts with others. PDD affects boys four times more often than girls. It is equally prevalent in people from all parts of society.
There are several different disorders that fall under the category of pervasive developmental disorders. - Autistic disorder, or autism, is the most severe of the PDDs. A person with autism has extreme difficulty in social interactions and communication. This is obvious before the age of 3 years.
- Asperger's disorder includes symptoms of difficulty in social interactions and little interest in activities. There usually is no difficulty with language skills. The person may be average or above average for age in intellectual testing.
- Rett's disorder is only seen in girls. It is characterised by normal behaviour at first and then sudden loss of skills and loss of control of the hands. This is followed by repetitive hand gestures, such as flapping. Symptoms usually begin between the ages of 1 and 4 years.
- Childhood disintegrative disorder, or CDD, is a disorder in which normal development is seen until the age of 2 years and then a loss of social skills and a tendency toward autistic behaviour occurs.
- Pervasive developmental disorder-nonspecific may be considered when symptoms of the other disorders are not present but there is a considerable difficulty with specific behaviours.
Symptoms can vary in intensity in any of these disorders. Some people may have severe symptoms that affect their lives dramatically. Others have symptoms that they are able to adjust for easily.
What are the signs and symptoms of the disease?
Symptoms of PDD depend on which type of disorder is present. The symptoms may include: - difficulty interacting with others
- distaste for cuddling, hugging, or being held
- difficulty expressing oneself, verbally and nonverbally
- a delay or lack of speech development
- regression in social interaction
- difficulty playing with others
Some people with PDD may show: - a tendency to injure themselves or aggressive behaviour to others
- repeated body movements, such as flapping arms, rocking back and forth, banging their head
- a tendency to repeat words or sentences over and over
- sensitivity to the five senses
- bizarre behaviours in social situations
What are the causes and risks of the disease?
The causes of PDD are not well known. Some cases may be genetic, although this has not been proven. What is known is that PDD is not caused by bad parenting, mental illness, or "that a kid just doesn't want to behave." Psychological factors have not been found to contribute to PDD.
Some cases of PDD have been associated with trauma, disease, or structural abnormalities before or during birth, including: - the mother having rubella, or German measles, while she was pregnant
- untreated phenylketonuria, a problem in the body's ability to handle certain chemicals named phenylketones
- lack of oxygen during birth
- encephalitis or other serious infections affecting the brain as an infant
- spasms from a variety of illnesses during infancy
What can be done to prevent the disease?
Since the cause of PDD is not known, PDD can be difficult to prevent. Early recognition and treatment may reduce the effects of PDD.
How is the disease diagnosed?
A team of healthcare professionals should evaluate the person with PDD. The team may include a developmental physician, a psychologist, a neurologist, a speech therapist, and learning consultant. Diagnosis begins with a history and physical examination. Further testing is then needed to identify other possible causes of the symptoms. These include blood tests, cranial CT scans, cranial MRI scans, and electroencephalograms (EEGs).
What are the long-term effects of the disease?
Long-term effects of PDD depend on how severe the symptoms are. Long-term effects also depend on how soon a person starts treatment. The symptoms of PDD may last a lifetime, but often these can be improved with careful intervention and treatment. In other cases, PDD may cause struggles for a lifetime.
What are the risks to others?
Pervasive developmental disorders are not contagious. It is not yet clear if some causes of PDD are genetic. Genetic counselling may be useful to couples with a family history of PDD.
What are the treatments for the disease?
Treatment for PDD first focuses on education. This should be tailored to each person's specific needs and symptoms. Some of the treatments include: - behavioural therapy to help the person handle his or her environment
- "inclusion programs" to help the person adapt to the outside world as much as possible
- providing a structured environment for the person
- audio-visual therapies
- dietary review
- medications, including antipsychotic medications, depending on the symptoms
- music therapy
- physiotherapy
- speech therapy
Treatment may also include teaching the person how to handle new situations. This can include asking for help, directions, and other needs. A person with a PDD often needs guidance in getting jobs and handling the daily work routine.
The families and friends of people with PDD need support as well. The more support they have, the better the adjustment to living with a person with PDD. Sometimes the person with PDD may need to go to a group home.
What are the side effects of the treatments?
Side effects depend on the treatments used. Behavioural therapy can cause frustration for the person and the family going through it. All medications have some side effects. Some of these include stomach upset, rash, irritability, depression, and allergic reaction.
What happens after treatment for the disease?
Treatment for PDD will usually last a lifetime. A person with a mild form of PDD may be able to monitor himself or herself for when treatment needs to continue. A person with a more severe form of PDD may need assistance with treatment and therapy programs.
How is the disease monitored?
PDD needs to be monitored closely. Treatments need to be adjusted over time. Persons with a mild form of PDD may improve as they mature. Those with a more severe form of PDD may worsen over time and may need adjustments to their treatment program. They may also have to rely on a caregiver to monitor their behaviour and help them get the care they need.
Author: Eileen McLaughlin, RN, BSN
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Contributors
Potential conflict of interest information for reviewers available on request |
