Skip to main content

What is Pervasive Developmental Disorder (PDD NOS)

Autism is a spectrum disorder, which typically means that the term “Autism” describes a range of different conditions. In the case of autism, these conditions are all neurodevelopmental disorders. So far, researchers have identified five types of neurodevelopmental disorders that fall under the umbrella term of autism. Autism, Asperger’s syndrome, Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS), Rett’s disorder, and Childhood Disintegrative Disorder.

pervasive developmental disorder PDD NOS

Autism PDD-NOS (pervasive developmental disorder not otherwise specified) is a neuro-developmental disorder that impairs the growth and development of the brain. Out of the various different types of autism, diagnosing physicians consider PDD-NOS an atypical autism; this is because individuals with the disorder often do not display the typical criteria normally presented by individuals with conventional or classical autism.

An often misconception of the PDD-NOS diagnosis is that it is a milder form of autism. While a PDD-NOS diagnosis may indicate that the individual presents some mild characteristics, other symptoms may be more severe than standard autism.

Note: In 2013, update to the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders Fifth Edition, also known as the DSM-V or DSM-5, researchers removed PDD-NOS as a diagnosis. However, it is still included in the ICD-10 (International Statistical Classification of Diseases and Related Health Problems) which is a list of diseases, their signs, symptoms, causes, and other information maintained by the World Health Organization (WHO). The United States adopted ICD-10 in October 2015, and it is the most recent iteration of the list.

Another term that some developmental health professionals use to refer to autism PDD-NOS is as “subthreshold autism”. This is used because individuals with this disorder have some, but not all of the characteristics of autism; alternatively, the individual could also have all of the symptoms but they might be relatively mild.

Parents and caregivers of children and adults with PDD-NOS need to remember that although the symptoms of  Pervasive Developmental Disorder suggests being a minor form of autism, each individual has their own challenges and struggles – just like any other human being.

Symptoms of Pervasive Developmental Disorder

People with the pervasive developmental disorder not otherwise specified type of autism have an atypical form of autism. Often the atypical nature of PDD-NOS means that a child, diagnosed with this particular form of autism, does not carry all of the stereotypically “classic” autistic symptoms.

Watch Kids Enact PDD NOS Symptoms

While the term “pervasive” might seem to mean that the disorder is present throughout the child’s functioning, this is not quite true. Generally, children with a pervasive developmental disorder, like autism PDD-NOS, will not have problems with all aspects of their developmental functionality. However, to better understand what is PDD-NOS it is important to know some common signs and symptoms of typical autism.

According to the DSM-5, diagnosis, the standard form of autism requires expression of the following symptoms:

Difficulties on a consistent basis with the social use of communication and interaction in a number of different contexts. This includes manifestation of such difficulties in the following contexts:

  • Inability to reciprocate social-emotional interaction. One example of this is that the individual may be unable to interact in a normal back and forth conversation, where one is required to take turns.
  • Inability to communicate in nonverbal manners or gestures. The most common form of this is the abnormality of maintaining eye contact.
  • Inabilities to develop, maintain, or understand a relationship. Some indicators of this deficit are best observed in the context of a child making friends or sharing in co-operative imaginative play.

Persistence in repetitive and sometimes compulsive behavior, interest, or activities as illustrated in at least two of the following examples:

  • Repetitive motor movements, use of objects, or speech. Commonly people notice this in hand flapping, meticulous lining up of objects, or repetitive speech (echolalia).
  • Compulsive and often inflexible adherence to routines or custom. Often the autistic individual will have extreme distress at even the smallest of changes to their daily routine or the layout of their surroundings.
  • Restricted and fixed interests with an abnormal level of focus and/or intensity. Often times, this will present itself with the individual finding a specific subject (e.g. Trains) and learning, and committing to memory, every detail about the subject.
  • Abnormal responses to sensory input. Some individuals will have no reaction to even large amounts of pain, while others will become extremely distressed at the touch of a specific texture.
pdd nos symptom chart

PDD NOS Symptoms @ a Glance

The previously mentioned symptoms have to be present during the early developmental period. Although, they may not become entirely apparent until placed in situations where social demands overwhelm their capabilities. Alternatively, later in life, the individual might no longer exhibit these symptoms as they can often learn strategies to minimize the presentation of the symptoms.

The presence of these symptoms should cause a clinically significant deficiency in a number of areas that the individual needs to function in society, including social and occupational areas.

The diagnosing clinician should not be able to explain these difficulties with another intellectual disability or a global developmental delay. However, an intellectual disability can occur alongside the autism spectrum disorder.

In contrast to these criteria for autism spectrum disorder, PDD-NOS symptoms have the following differences:

Other individuals will present many of the classic autistic symptoms; however, they will not meet all of the criteria. For example, some individuals with PDD-NOS will be able to hold a conversation with undiscernible difficulty from a neuro-typical individual but will present with all the other symptoms. The third group of people with autism PDD-NOS will meet all of the criteria for typical autistic disorder; however, their stereotypical and repetitive behaviors will be noticeably mild.

Autism PDD-NOS by the Numbers

Statistically speaking, a person is likely to receive an autism diagnosis at a rate of one in every 68 children, according to the Centers for Disease Control or CDC. Another way to look at this diagnosis is that for every 1000 people in the entire world, six of those people will have an autism spectrum disorder. These numbers have caused the global concern for autism awareness and research.

Of those six people diagnosed with autism, the distribution of the subordinate spectrum disorders is varied. For those with the “classic” form of autism, researchers estimate the prevalence of typical autism disorder to be somewhere between one and two individuals per 1000; alternatively, less than one individual in 1000 presents with an Asperger diagnosis (0.6 per 1000).

PDD NOS - The Most Prevalent Autism Type

PDD NOS – The Most Prevalent Autism Type

Childhood disintegrative disorder is even less at 0.02 individuals per 1000, or 1 individual per 50,000. In fact, the autism spectrum disorder that is most diagnosed is PDD-NOS, with a rate of 3.7 people per 1000.

As mentioned in the previous section, there are three typical subgroups of individuals diagnosed with autism PDD-NOS. The three categories are the high-functioning group, the atypical group, and the mild autism group.

Breakup of Kids with PDD NOS

Breakup of Kids with PDD NOS

Amongst PDD-NOS diagnosed individuals, the high-functioning individuals make up 1/4th of all people with the PDD-NOS diagnosis. Additionally, individuals who do not meet all of the classical autism diagnosis make up the 1/4th. The largest subsection of individuals with autism PDD-NOS is those that have the “milder” form of autism. Those individuals make up 50% of people with the PDD-NOS diagnosis.

Unlike other developmental and genetic diseases, researchers have found that the rates of autism, as well as the subordinate spectrum disorders, present themselves in a consistent manner regardless of culture or ethnic group. Researchers conclude that this is a universal disorder. The universality of the disorder is what has allowed for united efforts across all national lines in the effort to finding appropriate and effective treatment for the disorder.

pdd nos and autism is on the rise
autism gender statsWhile the disorder is consistent despite culture or ethnicity, there is one area that there is a disparity in diagnosis. Across gender lines, males tend to be affected far more frequently than females. The average ratio in autism spectrum disorder between both males and females is 4.2:1; meaning that for every one female diagnosed with an autism spectrum disorder 4.2 males will receive a diagnosis. While the overall rate of autism is one in every 68 people, females receive a diagnosis at a rate of everyone in 315. Alternatively, one in every 70 males will receive a diagnosis, which is coincidentally very close to the overall rate.

Pervasive Development Disorder (PDD-NOS) Treatment

Since autism PDD-NOS is a developmental disability, treatment for individuals is dependent upon the implementation of a number of different interventions. Autism experts consistently recommend that these interventions, or therapies, be implemented as early as possible and in an intensive manner.

The six commonly acceptable treatment options that autistic individuals will undergo are Visual Supports, ABA (applied behavioral analysis), Discrete Trial Instruction, Social Stories, Physical Therapy, and Occupational Therapy.

Visual Supports

Visual boards for PDD NOS Treatment

Visual boards for PDD NOS Treatment

A common method, especially amongst children with pervasive developmental disorder (not otherwise specified), is the use and reliance upon visual supports. Visual or environmental supports are the use of things like a daily bulletin board with the time, description, and a picture, of the daily activities the individual will engage in during the day.

Researchers have observed that the use of visual supports helps individuals with severe and mild PDD-NOS to pay attention to the tasks. These supports also help to reduce anxiety that is often associated with changes in schedule.

There are lot many online tools available for visual boards, check out our Apps for Autism page for a few examples.

Applied Behavior Analysis

Keeping in mind, that while none of the interventions are a cure for autism, Applied Behavior Analysis (ABA) has been shown to provide more lasting results in increased abilities for autistic individuals. There are a few different methods of ABA; however, the most common method is the Lovaas method.

Applied Behavior Analysis for PDD NOS

Applied Behavior Analysis for PDD NOS

The Lovaas method of ABA starts with the instructor creating behavioral procedures that they then request that the autistic individual perform. When the child (or adult) performs the action, the instructor rewards them with a motivator, often an object or treat. There are no punishments for failure to perform the action. The instructor will ensure that the individual has a day structure to provide multiple opportunities to practice the skill.

Additionally, they will train family and other caregivers to support the skill practice even while at home and outside. Typically, they start with a simple goal, like picking up a spoon, and then move on to more complex actions as the child progresses.

Discrete Trial Instruction

Often incorporated as a part of ABA, Discrete Trial Instruction (or discrete trial training) is a method where the instructor teaches the person with autism Pervasive Development Disorder a skill by breaking it down into its component steps.

Discrete Trial Instruction PDD-NOS Treatment

Discrete Trial Instruction PDD-NOS Treatment

One example of this would be learning to tie one’s shoes. An example of a discrete trial instruction plan would be to break it up into a number of steps. They build up to the full action by breaking it up into smaller tasks.

For Example, Putting on Your Shoes

  1. Get Shoes
  2. Put shoes on feet
  3. Close snaps / closures
  4. Get Shoes, put shoes on feet, close snaps or closures

Social Stories

Developed in 1991 social stories is a way to educate children on the autism spectrum. The main purpose of social stories is to give the child with PDD-NOS, a model of appropriate social interactions. Often these stories will start by describing a situation with explicit social cues.

social stories with visual boards are a powerful combination

Social Stories with Visual Boards are a powerful combination

They will usually show the story from various perspectives and often give the appropriate responses. Another distinct feature of these social stories is their reliance upon answering “Wh” questions (Why, What, Who, Where, When, and How). Additionally, they will use positively worded sentences to lead the child to the socially acceptable response.

Physical Therapy

Commonly associated with injuries and more physically related disabilities, one of the treatments for Autism PDD-NOS is using physical therapy. As stated earlier, one symptom of autism is sensory processing difficulties. Often children with autism will not respond in a typical way to touch, this will often lead to a lack of hand-eye coordination.

Another way that this manifests is that the individual might not put the appropriate pressure needed to perform an action, like riding a bike, so physical therapists work with the individual to get them accustomed to the activity or to improve their coordination.

Occupational Therapy

occupational therapy pdd nosChildren with autism PDD-NOS often have cognitive difficulties with understanding how to respond to situations. Many times, this is because as a social being most human interactions including work and academic pursuits are dependent upon having a high level of social and communicative ability.

The therapist will work with the child to learn how to respond to differing stimuli or cope with the reality of irregularity in a schedule. They also work to reinforce the skills that the other interventions work on establishing.

Parenting Tips for Children with Autism PDD-NOS

parenting tip for pervasive developmental disorder pdd nosHaving a child can be a difficult job to take on, and a child diagnosed with PDD-NOS will add to the stress that is involved with parenting. However, life of parents of a child with an autism PDD-NOS diagnosis do not necessarily have to be too hard.

In fact, if you remember four things you can easily navigate their way through the process of helping your child to cope with the difficulties their diagnosis may create for them.


Team Up With Your Child’s Teachers and Physicians

Treating autism PDD-NOS involves many different people. Depending on the type of PDD-NOS your child has, you may need to work with a large group of therapists and teachers. You may end up working with a speech therapist, physical therapist, occupational therapist, ABA instructor, teacher, doctor, neurologist, and more. In order to make things work out well for you, and your child, being acquainted and working as a team is key.

Research Socialization Opportunities for Your Child

Socialization is one of the main goals of the ABA therapy that your child will likely receive in school. Enrolling your child in various activities that can help them to practice their socialization skills is important. While your neuro-typical child can easily make friends and socialize without scheduled activities, children with autism PDD-NOS need to be motivated and pushed to interact with others. Organized activities are one way that they can easily obtain those skills.

Learn to Let Go of Your Expectations for Parenting

Often, when a parent is expecting the arrival of their child, the parent will have many expectations for the child’s future. Some people might have hopes that their child will follow their path and become a great lawyer or maybe be prom king or queen as they had been growing up. Do not feel bad about yourself if you feel sadness by losing those goals for your child, that is perfectly normal and it does not mean that you love your child any less. You just need to accept that your child has their own path, and will do many things that may surprise you.

Take Time For Yourself

It might seem counter-intuitive for you to take time for yourself, especially when you see just how much help your child needs to perform on par with other children their age. However, in order for you to be there for your child, you need to take time out for your own mental health and sanity. It does not make you selfish to take that time; which is often an objection that many parents of autistic children will have to this advice. This doesn’t mean that you have to take a week-long vacation, but it does mean take a half hour once a day to do something to relax, you’ll be better for it.

Please send us your suggestions on this post on Pervasive Developmental Disorder (PDD NOS)

Join the discussion 2 Comments

  • Farhana says:

    My son is 9 years year he will go to grade 1 his special school. He is good at memorizing and he can do all his ADLs by himself, can write, very well behaved and without any behaviour prblm…he also follows instructions of every body..his main problem is speech..he can’t and in some case dont want to express himself…He just tell his demand…nothing more…don’t interact with people verbally and sometimes I feel that he did not know what he actually have to say…what can I do to improve his socialization?

  • rosemary says:

    hello there…i’m a teacher and we had parents just this day who would like to enrol their son with the pdd case… We are a preschool teachrs.My question is ..does the child needs to be enrolled in a regular school or needs to stay on the therapy…What about his academics?. thank u so much.

Leave a Reply