Pervasive Developmental Disorder

Pervasive developmental disorder is a type of psychological disorder that is characterized by a delay in child development. Other problems include trouble with change in routine, problems with socializing, communication, repetitive movements, and behavioural complications.

In 2013, The American Psychiatric Association reclassified pervasive developmental disorder, autistic disorder, Asperger’s syndrome, and childhood disintegrative disorder and placed them under the autism spectrum disorders. This means that pervasive developmental disorder is not a term used by doctors anymore.

The spectrum concept is known to be more medically accurate in diagnosing children who have these disorders. Pervasive developmental disorder occurs during the infancy stage, but the disorder is not usually identified until the child reaches three years of age.

When a developmental milestone (such as speech production and age-appropriate movements) are not met, the parents might begin to question the health of their child and seek help.

Children who have PDD display different levels of intelligence, abilities, and behaviours. While some children have a speech impairment, others may possess limited phrases. Some children with PDD may have an unusual response to sensory stimuli such as lights or loud sounds.


Pervasive developmental disorder is characterized by the following symptoms:

  • Problems with social communications and interaction
  • Inappropriate social behaviour
  • Inability to express what they are thinking through language. They usually have difficulty understanding and interacting
  • Inability to start, hold or keep up conversations
  • Problems relating to people and events. This includes avoiding eye contact, lack of facial expressions, and pointing behaviour
  • Poorly developed skill development, such as motor, cognitive, social, academic, visual, and behavioural
  • Having trouble controlling emotions. They can have emotional break downs like throwing tantrums, aggression, anxiety, and it is difficult for them to be comforted
  • Engaging in repetitive behaviour or movements such as rocking, twirling, jumping, foot-tapping, turning lights on and off, shutting and opening doors
  • Have a high-pitched or a flat voice
  • The need to adhere and stick to a routine or familiar environment
  • Unusual play with toys and objects. They usually have an odd interest in parts of the toy rather than the toy itself
  • Disinterest in cuddling
  • Unusual response to sensory stimuli such as light, and loud sounds
  • Heightened or decreased sensitivity to sensory stimuli or information such as taste, light, sound, smell, and touch

Causes of pervasive developmental disorder

The causes of PDD are still unknown. However, scientists believe that genetics play a vital role in the development of this disorder. It is also believed that many things, in addition to the genes, may be involved.


Diagnosis is usually made during early childhood, and there are no laboratory tests for PDD. For doctors to make an accurate diagnosis, the child’s behavioural pattern has to be understood.

When the child does not meet the diagnostic criteria for autism and is generally considered to exhibit mild symptoms of autism, then the child may be diagnosed with PDD.

Pervasive developmental disorder is also referred to as PDD-NOS (Pervasive developmental disorder not otherwise specified). This is because of the debate among experts concerning exactly how to classify children who have the disorder.

Recent studies suggest that people with PDD can be placed under one of the three different subgroups:

  • The first group is known as the high-functioning group. The symptoms they experience mainly cover that of the Asperger syndrome. However, they differ in terms of having a delay in language development and mild cognitive impairment
  • The second subgroup are people whose symptoms are closely similar to that of the autistic disorder but don’t meet the diagnostic criteria
    The third group includes people who meet all the diagnostic criteria for the autistic disorder, but their preservative and repetitive behaviour are mild


In the year 2013, The Diagnostic and Statistical Manual fifth edition (DSM5) was released and updated the classification of PDD. It grouped the following disorders:

They are all placed under the general term of Autism spectrum disorder.

The American Psychiatric Associations (APA) arrived at the conclusion that using the general diagnosis of the autism spectrum disorders supports more accurate results. The combination of this disorder is motivated by the fact that autism is characterized by similar symptoms and, therefore, should bear the same diagnostic term.

To differentiate between the different disorders, the DSM-5 adopts severity levels. The severity levels consider and regard required support, restricted interests, repetitive behaviours and deficits in social communication.


There is no known cure for PDD; however, to address specific behavioural problems, the use of medications is adopted. Therapy for PDD can also be adopted. They are specially designed to suit the child’s specific needs.

It is also essential to note that medications work best along with side therapy. Therapy can be incorporated to help an affected child improve their social skills, interactions, and other life skills.

Early intervention plays a vital role in improving the outcome of children with PDD. With early intervention, the child can be helped to reach his or her full potential—the earlier the diagnosis and treatment, the better.


Children or adults who have pervasive developmental disorder experience the world differently. It goes a long way to appreciate them for their unique interest and personalities. It also helps to assist them by providing support and skills that could contribute to making a big difference in their future.