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PDD-NOS or pervasive developmental disorder-not otherwise specified, was one of five categories of an autism diagnosis.

In the past, a diagnosis of PDD-NOS was given if a person was determined to have some symptoms of autism but didn’t meet the full diagnostic criteria for conditions like autistic disorder and Asperger’s syndrome.

PDD-NOS was diagnosed prior to 2013 when an individual had impairment in social skills, the inability to successfully interact with other people, problems with verbal or nonverbal communication, or stereotyped behavior, interests, and activities.

PDD-NOS was one of five diagnoses included in the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR) published in 2000.

PDD-NOS only applied to people who didn’t have any of the following diagnoses:

  • specific pervasive developmental disorder
  • schizophrenia
  • schizotypal personality disorder
  • avoidant personality disorder

PDD-NOS also included the diagnosis of atypical autism, which was used when an individual’s symptoms didn’t meet the full criteria for an autistic disorder diagnosis, either because the symptoms appeared or were diagnosed at an older age, they weren’t the typical symptoms of autism, or both.

In 2013, the American Psychiatric Association updated the DSM to its fifth edition. With this change, the entire category of “pervasive developmental disorders” was eliminated, and the diagnosis of PDD-NOS was no longer used.

Instead, these disorders were placed under the autism spectrum disorder diagnosis in the “neurodevelopmental disorders” category.

Read on to learn more about what PDD-NOS was, what the current diagnostic criteria says, and how the condition is diagnosed and treated today.

Previously, the DSM-4 divided autism into five separate categories. These were:

  • autistic disorder
  • Rett syndrome
  • Asperger’s syndrome
  • childhood disintegrative disorder

A diagnosis of PDD-NOS could be given to someone with mild or high-functioning symptoms who didn’t meet all of the criteria for an Asperger’s diagnosis. Similarly, this diagnosis might have been given for those who didn’t meet all of the required diagnostic criteria for Rett syndrome.

In the DSM-5, these conditions are now grouped under a single diagnostic label: autism spectrum disorder (ASD).

Previously, people were diagnosed with PDD-NOS when they didn’t display symptoms consistent other conditions under the “pervasive developmental disorder” category.

Symptoms of a pervasive developmental disorder included:

  • problems using and understanding language
  • difficulty relating to people
  • unusual play with toys
  • problems with changes in routine
  • repetitive movements or behavior

In the DSM-5, symptoms of PDD-NOS and other autism categories were consolidated. Since 2013, the symptoms of ASD now fall into two categories, which include:

  • deficits in communication and interaction
  • restricted or repetitive movements

Individuals with autism spectrum disorder are evaluated based on the severity of these symptoms, and the severity is determined based on the level of support they need in each category. The categories have unique symptoms.

Social communication and interaction symptoms can include things like:

  • having difficulties initiating or maintaining a conversation
  • making poor eye contact or not making eye contact at all
  • having a hard time expressing feelings or emotions, or not understanding the feelings of others
  • not understanding nonverbal cues, such as facial expressions, gestures, or postures
  • being slow to respond to someone calling out their name or trying to get their attention

Restrictive or repetitive behavior symptoms may be things like:

  • engaging in repetitive behaviors, such as rocking back and forth or repeating specific words or phrases
  • maintaining a specific routine and becoming upset when there are even slight changes to it
  • having a greater or lesser sensitivity to sensory stimulation, such as noises or lights
  • having an intense, very focused interest in specific objects or topics
  • developing specific food preferences or refusing to eat certain foods

When diagnosing ASD, medical professionals rate the level of support a person needs for their day-to-day functioning on a scale of one to three for each of the two categories.

They also need to specify if symptoms are associated with:

  • intellectual impairment
  • language impairment
  • a known medical or genetic condition or environmental factor
  • another neurodevelopmental, mental, or behavioral disorder
  • catatonia

ASD is a very complex condition, and not all of the causes are known. It’s generally agreed that a combination of genetic and environmental factors likely play a role in causing the condition.

Genetically speaking, mutations may be a contributing factor, but science is currently inconclusive on this. ASD is often described as genetically heterogeneous (meaning it may have many causes).

Additionally ASD may be associated with certain genetic disorders such as fragile X syndrome or Rett syndrome.

As with possible genetic causes, researchers are continuing to investigate potential environmental causes and other risk factors for ASD. Some examples of topics that are being investigated include:

  • viral infections
  • medications taken during pregnancy
  • environmental pollutants
Risks for autism

Currently, the risk factors for ASD can include:

  • having a family member with ASD (including siblings or parents)
  • exposure to heavy metals and other environmental toxins
  • boys are more likely to develop ASD than girls
  • children born to older parents
  • being born very premature or at a low birth weight
  • having genetic conditions, such as fragile X syndrome or Rett syndrome

In addition, if a pregnant person takes certain prescription drugs that have been linked to ASD, it raises the risk.

Some people worry that ASD may be associated with childhood vaccinations. As such, this has been a very heavy area of study over many years. However, research has found no link between vaccines or their components and the development of ASD.

Because PDD-NOS is not included in the DSM-5, it probably will not be diagnosed by an up-to-date physician. Rather, those who once would have received a diagnosis of PDD-NOS might now receive an ASD diagnosis and severity rating.

If your child was diagnosed with PPD-NOS prior to 2013, you may need to have them reevaluated by a doctor and given an updated diagnosis and treatment recommendations.

Children should receive regular developmental screenings as part of every routine wellness checkup.

During these screenings, the doctor will ask you questions about your child’s development and assess how the child communicates, moves, and behaves.

In addition, the American Academy of Pediatrics (AAP) recommends all children be screened specifically for ASD between 18 and 24 months of age.

If they notice any signs of a possible developmental problem, they’ll request a second more comprehensive screening. They may perform this screening themselves or refer you to a specialist, such as a developmental pediatrician, psychologist, or child neurologist.

ASD can also be diagnosed in older children, adolescents, and adults by evaluation by a primary care doctor or someone who specializes in ASD.

There are a variety of treatments available for ASD, which includes PDD-NOS.

Below, we’ll briefly explore some of them:

  • Applied behavioral analysis (ABA). There are several different types of ABA. At its core, ABA is concerned with reinforcing positive behaviors while discouraging negative behaviors.
  • Speech or language therapy. This type of therapy can help with deficits in language or communication.
  • Occupational or physical therapy. These can help with coordination issues and also with learning day-to-day tasks such as getting dressed and bathing.
  • Medications. There are no medications to treat ASD directly. However, other conditions such as anxiety and depression often occur along with ASD. Medications can help treat these conditions.
  • Cognitive behavioral therapy. Cognitive behavioral therapy can help people with ASD in dealing with anxiety, depression, or other psychological challenges they may be experiencing.
  • Dietary changes. This can include things like gluten- or casein-free diets or using vitamin or probiotic supplements. Currently, most of these haven’t shown proven benefits, so you should speak to your pediatrician before changing your child’s diet.
  • Alternative or complementary therapies. These can include a variety of things such as music therapy, massage therapy, and herbal medicine. It’s important to remember that there isn’t a lot of research into the efficacy of many of these therapies, while others have been shown to be ineffective. Some of these therapies may come with significant risk, so speak with a doctor before starting one.

There’s no cure for ASD. However, early diagnosis and starting treatment sooner is important. This will ensure that autistic people get the help that they need and receive the tools necessary to learn to function within their environment.

No two people with ASD are the same. The outlook can depend on the symptoms that are present as well as their severity. Your doctor will work closely with you to come up with a treatment plan that’s right for you or your child.

PDD-NOS was one of the categories of pervasive developmental disorder found in the DSM-4. It involved symptoms that placed an individual on the autism spectrum, but weren’t consistent with other categories of PDD found in that version of the DSM.

As of 2013, PDD-NOS is no longer a diagnosis. It’s instead included under the umbrella diagnosis of autism spectrum disorder (ASD).

ASD is typically diagnosed in young children, but can be diagnosed in older individuals as well. There are many possible treatment options available to people with ASD. Many of them focus on promoting better social and communication skills and lessening negative behaviors.

Every person with ASD is different. When deciding on a treatment plan, you’ll work alongside your doctor to determine an optimal course of treatment for you or your child.