“Does your patient have a psychiatric illness or nonverbal learning disorder?” (Current Psychiatry, May 2011, p. 17-35) reviews the differential diagnosis of “nonverbal learning disorder.”
Nonverbal learning disorder (NLD) has yet to be established as a distinct, valid neurodevelopmental syndrome. Many of the proffered diagnostic criteria, clinical presentations, and laboratory findings (especially results from psychological/neuropsychological and psychoeducational testing) overlap considerably with other neurodevelopmental syndromes characterized by social inadequacy and peculiarity, including Asperger’s disorder.
Therefore, rather than representing a discrete diagnostic category with overlapping features as suggested by this article, this putative syndrome probably is best conceptualized as falling within the milder end of a neurodevelopmental disorder spectrum characterized by deficits in social competence, judgment, and perception, accompanied by impaired daily functioning referable to these difficulties. The DSM-5 workgroup appears to recognize this problem of “splitting” vs “lumping.” Reports indicate that Asperger’s disorder may no longer be considered a “standalone” clinical syndrome and likely will be reconceptualized as a mild form of autism.
Many individuals have cognitive/neuropsychological and academic/learning difficulties compatible with nonverbal learning problems and do not exhibit the difficulties with social interactions the article cites. One way to advocate for NLD as a distinct clinical syndrome is to limit the diagnosis to a certain constellation of cognitive/neuropsychological and academic impairments that lead to educational, interpersonal, and/or vocational difficulties. Patients who also display clinically significant neurodevelopmentally based deficits in social competence/skills would fall outside this category and would be placed within the milder end of the autistic spectrum, or perhaps included within a broader “neuro-social disorder” spectrum. As the authors aptly point out, psychometric testing is important for diagnosis and psychoeducational planning for patients with the information processing difficulties and life struggles well described in this article.
Jerrold Pollak, PhD
Coordinator, Program in Medical and
Seacoast Mental Health Center
The authors respond
We thank Dr. Pollak for his comments. Although considerable overlap may exist among “neurodevelopmental syndromes characterized by social inadequacy and peculiarity,” we sought to draw attention to the specific neurocognitive differences in NLD as compared with other disorders that, despite potentially sharing features with NLD, are distinct disorders.
We agree with Dr. Pollak’s suggestion that NLD someday might be classified within the DSM along a “neurodevelopmental disorder spectrum characterized by deficits in social competence, judgment, and perception accompanied by impaired everyday functioning referable to these difficulties.” This process will require careful characterization of individuals with NLD—as well as other individuals with difficulties in visual-spatial integration, attention, nonverbal memory, and expression and integration of emotion—to establish convergent and discriminant validity for NLD. Further, we believe that recognition of NLD as a distinct disorder will facilitate research and development of specific treatment interventions as compared with other conditions, despite potential syndromic or symptomatic overlap with NLD.
Sergio V. Delgado, MD
Professor of Psychiatry, Pediatrics,
Elizabeth Wassenaar, MD
Resident in Psychiatry, Child and Adolescent
Psychiatry, and Pediatrics
Jeffrey R. Strawn, MD
Assistant Professor of Psychiatry
Cincinnati Children’s Hospital Medical Center
University of Cincinnati College of Medicine