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NLD and Asperger's Disorder

Joe Palombo

Nonverbal Learning Disabilities, Chapter 11, pages 205-218

NLD Contrasted with DSM-IV Criteria for Asperger's Disorder

In spite of the doubts cast on the validity of DSM-IV's criteria of Asperger's disorder (Klin &: Volkmar, 2003), a comparison of the features of the four subtypes of NLD with the DSM-IV criteria for Asperger's disorder (see Table 11.1) would reveal clear-cut differences. There is little question as to the difference between NLD subtypes I and II, and Asperger Disorder. It is only when we consider children with the types of impairments in social cognition that are found in NLD subtypes III and IV that questions may be raised as to whether they are distinct disorders or lie along a continuum. Perhaps making a differential diagnosis between a severe case of NLD subtype IV and Asperger Disorder would present the greatest challenge. I believe that we would then have to fall back on the clinical impression derived from the assessment of the child's intrapersonal status. The questions would center on whether the capacity for mindsharing confounds the diagnostic picture, whether the desire for isolation is defensive or essential to the child, whether the child’s sense of self-cohesion is relatively stable, and finally, whether the child is capable of constructing a coherent self-narrative, with help.

Table 11.1. DSM-IV Criteria for Asperger's Disorder

A. Qualitative impairment in social interaction, as manifested by at least two of the following:

  1. marked impairment in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body postures, and gestures to regulate social interaction
  2. failure to develop peer relationships appropriate to development level
  3. a lack of spontaneous seeking to share enjoyment, interests, or achievements with other people (e.g., by a lack of showing, bringing, or pointing out objects of interest to other people)
  4. lack of social or emotional reciprocity

B. Restricted repetitive and stereotyped patterns of behavior, interests, and activities, as manifested by at least one of the following:

  1. encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus
  2. apparently inflexible adherence to specific, nonfunctional routines or rituals
  3. stereotyped and repetitive motor mannerisms (e.g., hand or finger flapping or twisting, or complex whole body movements)
  4. persistent preoccupation with parts of objects.

C. The disturbance causes clinically significant impairment in social, occupation, or other important areas of functioning.

D. There is no clinically significant general delay in language (e.g., single words used by age 2 years, communicative phrases used by age 3 years).

E. There is no clinically Significant delay in cognitive development or in the development of age-appropriate self-help skills, adaptive behavior (other than in social interaction), and curiosity about the environment in childhood.

F. Criteria are not met for another specific Pervasive Developmental Disorder or Schizophrenia.

Printed by permission of The American Psychiatric Association.

If we were to contrast the features of severe NLD subtype IV with those of Asperger's Disorder on DSM-IV criteria, we would find that the features listed in item A ("Qualitative impairment in social interaction") of the criteria for Asperger Syndrome are identical to those for autistic disorder and are similar to many of the social impairments that are common in children; with NLD subtype IV.   What DSM-IV criteria leave unstated is the level of severity of those features. Taken alone, the criteria in item A would apply to many children with a variety of emotional disturbances who do not belong in the autistic spectrum (e.g., shy children, some children with social phobias or severe anxiety disorders).

The descriptions listed in item B ("restricted repetitive and stereotyped patterns of behavior, interest, and activities") are identical to those listed for autistic disorder in item C ("the disturbance causes clinically significant impairment in social, occupational, or other important areas of functioning"), with the possible exception of item B-1 ("encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus"). These features are uncommon in children with NLDs.  However, because the criteria state that one feature would be sufficient to diagnose a child with the disorder, we must ask whether the characterization of "encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus" is applicable to children with NLD subtype IV I would argue that, in my clinical experience, some of the children have demonstrated unusual rote memory, but their interests were not all encompassing, nor were they of such intensity as to interfere with their I relationships to others. Neither item B-2 ("apparently inflexible adherence to specific, nonfunctional routines or rituals") nor B-3 ("stereotyped and repetitive motor mannerisms [e.g., hand or finger flapping or twisting, or complex whole-boy movements]") applies to children with NLDs.

Regarding item C ("the disturbance causes clinically significant impairment in social, occupational, or other important areas of functioning"), although the children's relationships with others are problematic and at times unsatisfactory, only in the severe cases of subtype IV do these cause "significant impairments ... of functioning." Items D, E, and F would apply to children with NLD subtypes I or II. If applied to NLD Subtypes III or IV, then making a valid differentiation would require more than a simple comparison among the children's symptoms. For each subtype we would need a developmental perspective that traces the path a child takes from birth on. It would also be essential to compare the mental processes that a child uses to organize his or her experience. Finally, the response of the child to clinical interventions is another important diagnostic determinant in that they may confirm or falsify a diagnosis.

We may now draw a sharp contrast between the profiles of children with Asperger’s disorder and those with NLDs. From a neurobehavioral perspective, most of the children with NLDs have milder symptoms than those of children with Asperger’s disorder. Their nonlinguistic perceptual deficits are not as severe and they may have attentional or executive function problems, but those do not necessarily interfere with their vocational adjustment. From the perspective of social cognition the capacity of children with NLDs for reciprocal social relationships may be impaired but it does not preclude their ability to sustain a relationship with another person. They are capable of a degree of mindsharing functions and have theory of mind abilities, which is not true of children with Asperger's disorder. The pragmatic language problems of children with NLDs are moderately severe and, at times, can interfere with their ability to communicate, but their strengths in verbal expression can help them compensate for that deficit. In contrast, children with Asperger's disorder have severe pragmatic language problems that often interfere with the possibility of sustaining a meaningful conversation with them. Their communications are centered on topics they wish to discuss, they disregard signals of disinterest from their listeners. Furthermore, their capacity to process affective states is similarly more impaired than that of children with NLDs. For the latter group of children, processing affective states is problematic but for the former group it appears to constitute a foreign language.

Finally, from an intra personal perspective the contrast between the two groups is greatest. Children with Asperger's disorder have critical deficits in theory of mind abilities and in mindsharing capacities. Their sense of self lacks cohesion and they are incapable of providing a coherent self-narrative. Children with NLDs have and unstable sense of self-cohesion but can sustain that sense of cohesion when not under stress and can use the complementary functions that others provide to maintain that cohesion. Their self-narrative have lacunae caused by their deficits and their inability to understand the nature of their disorder. However, there are able to provide a reasonable account of their life stories even though these might be based on the personal meanings they have drawn from their experiences and might not make complete sense to others.

The contrast between the two disorders appears smallest in the severest cases of NLDs (ie., NLD Subtype IV).  In those case, I believe that DSM-IV criteria come to the rescue in a making a differentiation.  As I described above, many of item B's criteria and those of item C do not apply to children with NLD. Children with NLDs can function independently; they formulate plans and goals to achieve vocationally With assistance they are able to understand the nature of their deficits and arrive at coherent narratives of the effects those deficits have had on their development. My clinical experience with adults diagnosed with NLDs confirms that impression. Some of these adults have achieved considerably in their chosen careers. They remain in successful relationships, have raised children, and given every indication of being good caretakers and providers. In contrast, adults with Asperger's disorder whom we have treated demonstrate impairments that limit severely both their careers and their relationships with others.

I conclude that NLD and Asperger's disorder are distinct diagnostic disorders.