By Katie Weisman, for the SafeMinds Research Committee Introduction
This month, the American Psychiatric Association will publish the latest edition of its Diagnostic and Statistical Manual – the DSM-5. The manual contains significant changes to the diagnostic criteria for individuals with autism.
1. The name of the category will be changed from Pervasive Developmental Disorder to Autism Spectrum Disorder.
2. The four previous diagnoses: Autistic Disorder, Asperger’s Syndrome, Pervasive Developmental Disorder- Not Otherwise Specified and Childhood Disintegrative Disorder will all be combined into the single category of Autism Spectrum Disorder. Rett Syndrome will be eliminated from the manual since the gene that causes it has been identified.
3. Three symptom domains will be reduced to two by combining the speech and social symptoms into a single category. The number of criteria has been reduced from 12 to 7 which reduces the number of possible combinations of symptoms to receive an ASD diagnosis.
4. Severity codes will be added for each symptom domain, though the details will not be clear until the new manual is published.
5. Criterion B4 adds a sensory component to the diagnosis for the first time.Criteria
The new criteria under the DSM-5 are as follows:
Autism Spectrum Disorder
Currently, or by history, must meet criteria A, B, C, and D:
A. All individuals must have or have had persistent deficits in social communication and social interaction across contexts, not accounted for by general developmental delays, and manifest by all 3 of the following:
1. Deficits in social-emotional reciprocity; ranging from abnormal social approach and failure of normal back and forth conversation through reduced sharing of interests, emotions, and affect and response to total lack of initiation of social interaction,
2. Deficits in nonverbal communicative behaviors used for social interaction; ranging from poorly integrated- verbal and nonverbal communication, through abnormalities in eye contact and body-language, or deficits in understanding and use of nonverbal communication, to total lack of facial expression or gestures.
3. Deficits in developing and maintaining relationships, appropriate to developmental level (beyond those with caregivers); ranging from difficulties adjusting behavior to suit different social contexts through difficulties in sharing imaginative play and in making friends to an apparent absence of interest in people
B. All individuals must have or have had restricted, repetitive patterns of behavior, interests, or activities as manifested by at least two of the following:
1. Stereotyped or repetitive speech, motor movements, or use of objects; (such as simple motor stereotypies, echolalia, repetitive use of objects, or idiosyncratic phrases).
2. Excessive adherence to routines, ritualized patterns of verbal or nonverbal behavior, or excessive resistance to change; (such as motoric rituals, insistence on same route or food, repetitive questioning or extreme distress at small changes).
3. Highly restricted, fixated interests that are abnormal in intensity or focus; (such as strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interests).
4. Hyper-or hypo-reactivity to sensory input or unusual interest in sensory aspects of environment; (such as apparent indifference to pain/heat/cold, adverse response to specific sounds or textures, excessive smelling or touching of objects, fascination with lights or spinning objects).
C. Symptoms must be present in early childhood (but may not become fully manifest until social demands exceed limited capacities)
D. Symptoms together limit and impair everyday functioning.
In addition, the DSM-5 introduces a new disorder, not on the autism spectrum, with the following criteria:Social Communication Disorder
A. Social Communication Disorder (SCD) is an impairment of pragmatics and is diagnosed based on difficulty in the social uses of verbal and nonverbal communication in naturalistic contexts, which affects the development of social relationships and discourse comprehension and cannot be explained by low abilities in the domains of word structure and grammar or general cognitive ability.
B. The low social communication abilities result in functional limitations in effective communication, social participation, academic achievement, or occupational performance, alone or in any combination.
C. Rule out Autism Spectrum Disorder (ASD). Autism Spectrum Disorder by definition encompasses pragmatic communication problems, but also includes restricted, repetitive patterns of behavior, interests or activities as part of the autism spectrum. Therefore, ASD needs to be ruled out for SCD to be diagnosed.
D. Symptoms must be present in early childhood (but may not become fully manifest until social demands exceed limited capacities).
Social Communication Disorder will be the diagnosis for anyone who meets all three of the Autism Spectrum Disorder speech and social criteria but none of the repetitive and restrictive behavior criteria. There is currently a gap between ASD and SCD, with no clear diagnosis for someone with all three speech/social domain criteria but only one criterion under the restricted and repetitive behavior/sensory domain.Research Update
The following are brief descriptions of the research studies that have attempted to compare the old and new criteria for autism spectrum disorders. This list includes only those studies using the above DSM-5 criteria, not those studies done using previous versions of the new criteria.
As a brief explanation, the goal of the new criteria was to get the best possible combination of sensitivity and specificity of diagnosis. Sensitivity is the ability of the criteria to correctly identify all cases who actually have a disorder (to not miss anyone). Specificity is the ability of the criteria to correctly screen out those who do not have a diagnosis and eliminate false positives. The two are in tension with each other, as increasing one often reduces the other. In the case of the DSM-5 ASD criteria, the specificity appears to be excellent, but the research so far has raised concerns that the new criteria are too restrictive, thereby reducing the number of individuals who will be diagnosed (lower sensitivity).McPartland, Reichow and Volkmar, 2012
This study looked at the records of 657 individuals, aged 12 months-43 years who participated in the clinical trials for the DSM-IV. It re-evaluated those individuals using the DSM-5 criteria and found that 39.4% would no longer qualify for a diagnosis on the autism spectrum. Those most affected by the change had IQ’s >70; sex and age were comparable in those meeting and not meeting the new criteria. By diagnosis, the new criteria excluded 24.2% of those with Autistic Disorder, 75% of those with Asperger’s disorder and 71.7% of those with PDD-NOS. One criticism of this study is that, since the DSM-IV criteria did not include a sensory criterion, no data was collected in the original files that might have fulfilled that criterion for the DSM-5.Matson et al. 2012
This study screened a population of 2721 toddlers (age 17-36 months) at risk for a developmental disability. 415 toddlers met the criteria for an autism spectrum disorder using the DSM-5 criteria and an additional 380 toddlers met the criteria for either Autistic Disorder or PDD-NOS based on the DSM-IVR criteria. The researchers assumed that any child who met DSM-5 criteria would also meet DSM-IVR criteria since it is less restrictive. Their conclusion was that, potentially, there could be a 47.79% decrease in diagnosis as a result of the proposed criteria. Children who met criteria for PDD-NOS were disproportionately impacted – 79.94% of them did not meet the proposed DSM-5 criteria for ASD. A weakness of this study is that it did not actually diagnose the children. The data was based on care-giver reports.Gibbs et al. 2012
This study was done in Australia and the team actually did new diagnoses on 132 referral cases. The subjects ranged from 2 to 16 years of age (Mean=6.06; SD=3.38). The ADOS and the ADI-R were administered to each child and their caregiver. A total of 111 children were diagnosed with Autistic Disorder, PDD-NOS or Asperger’s Disorder using the DSM-IVR criteria. Of those, 26 did not meet the criteria for Autism Spectrum Disorder using the proposed DSM-5 criteria – a decrease of 23.4%. Again, the children diagnosed with PDD-NOS were most impacted – comprising about 2/3 of the decrease. This study identified the requirement for two criteria under the Restrictive and Repetitive Behavior domain as the most common reason for exclusion.DSM5 – Field Trials 2012
Dr. Susan Swedo, chair of the Neurodevelopmental Disorders Workgroup for the DSM-5, presented the results of the DSM-5 field trials for autism to the Interagency Autism Coordinating Committee in July, 2012. Her power point presentation indicated that the decrease in the number of identified ASD cases using the proposed criteria would be counter-balanced by the inclusion of some cases that had been missed by the DSM-IVTR. The field trials for ASD were done at two pediatric sites and screened a total of 293 children ages 6-17. Of these, 214 did not meet criteria under the DSM-IVTR criteria and 79 did. An additional 19 children met the DSM-5 criteria for ASD and 10 met the criteria for SCD. This may be the result of the addition of sensory criteria for ASD and the SCD cases may have come from the pool of children who would normally have fallen in another diagnostic speech/language category.
Of the 79 children who met criteria for an ASD under DSM-IVTR, 64 met an ASD diagnosis under DSM-5, which would be a 19% decrease. Including Social Communication Disorder substitutions is questionable because that will not be considered an ASD under the new criteria. However, the 19 additional children identified under DSM-5 balanced out the 15 that were dropped. 7 of 17 children, who met criteria for Social Communication Disorder, would have met the DSM-IVTR ASD criteria. These children likely represent the ones most at risk for reduced services. They represented about 9% of the children meeting the DSM-IVTR criteria.
Below is the field trial data as presented to the IACC in July 2012. The full power point is available at http://iacc.hhs.gov/events/2012/slides_susan_swedo_071012.pdf
Read the rest of the post at the SafeMinds site here.