Questions and Answers
Question #24


Questions and Answers

Questions and Answers


Question # 24

Are there subtypes of NLD?

Short answer: No.

The attempts to delineate subtypes of NLD that I have encountered have in common one dimension: The confusion of the syndrome of NLD (i.e., its neurodevelopmental assets, deficits, and dynamics) with its most predominant behavioural (essentially, "dependent variable") manifestations.

It is clear that persons with NLD may be seen to have their maximal difficulties in adaptation within the psychosocial sphere, or the academic sphere, or in emotional control, etc.
This does not mean that there are subtypes of NLD. It only implies that the manifestations of NLD may be more prominent, at any particular time, in one area rather than in another.

Consider the analogy of influenza as a substitute for NLD.
The 20-year-old who contracts a particular strain of influenza may need to stay home from school or work. But, the 80-year-old who contracts the same strain may die of it. Does that mean that there are subtypes of this strain of influenza (one relating to absence from school or work and the other with death)? Of course not. To suggest so is to misconstrue the concept of subtypes in psychological or other branches of science.

In my experience and in that of many others, there are variations in the expression of NLD. But, these have to do with the outstandingly important demands of a particular developmental epoch (e.g., being 8 years of age and trying to cope with the demands of school versus being 30 years of age and trying to do a job or establish an intimate relationship). Also, there are variations in degree of nonadaptive manifestations of NLD. For example, it is reasonable to consider mild, moderate, and severe manifestations of NLD at any particular developmental stage.

None of this would imply that there are subtypes of NLD. Furthermore, there is no scientific evidence to support the view that there are subtypes of NLD as is the clearly the case for traumatic brain injury (Butler, Rourke, Fuerst, & Rourke, 1997; Hayman-Abello, Rourke, & Fuerst, 2003; Warriner, Rourke, Velikonja, & Metham, 2003), Alzheimer's disease (Fisher, Rourke, Bieliauskas, Giordani, Berent, & Foster, 1997), psychosocial functioning (Rourke & Fuerst, 1991; Tsatsanis, Fuerst, & Rourke, 1997); disabilities in arithmetic calculation and mathematics (Rourke, 1993; Rourke & Conway, 1997); and, below-average IQ (Ralston, Fuerst, & Rourke, 2003). For reviews of issues involved in neuropsychological subtyping, the interested reader may wish to consult Rourke (1985; 1991). For recent comprehensive reviews of such neuropsychological subtyping studies in children and adolescents, see Rourke (2000), Rourke et al. (2002), and Rourke, Hayman-Abello, and Collins (2003). Also, some of the important clinical implications of such subtyping efforts are discussed in Rourke (1995) and in Rourke, van der Vlugt, and Rourke (2002).


Butler, K., Rourke, B. P., Fuerst, D. R., & Fisk, J. L. (1997). A typology of psychosocial functioning in pediatric closed-head injury. Child Neuropsychology, 3, 98-133.

Fisher, N. J., Rourke, B. P., Bieliauskas, L. A., Giordani, B., Berent, S., & Foster, N. L. (1997). Unmasking the heterogeneity of Alzheimer’s disease: Case studies of individuals from distinct neuropsychological subgroups. Journal of Clinical and Experimental Neuropsychology, 19, 713-754.

Hayman-Abello, S. E., Rourke, B. P., & Fuerst, D. R. (2003). Psychosocial status after pediatric traumatic brain injury: A subtype analysis using the Child Behavior Checklist. Journal of the International Neuropsychological Society, 9, 887-898.

Ralston, M. B., Fuerst, D. R., & Rourke, B. P. (2003). Comparison of the psychosocial typology of children with below average IQ to that of children with learning disabilities. Journal of Clinical and Experimental Neuropsychology, 25, 255-273.

Rourke, B. P. (Ed.). (1985). Neuropsychology of learning disabilities: Essentials of subtype analysis. New York: Guilford Press.

Rourke, B. P. (1993). Arithmetic disabilities, specific and otherwise: A neuropsychological perspective. Journal of Learning Disabilities, 26, 214-226.

Rourke, B. P. (Ed.). (1991). Neuropsychological validation of learning disability subtypes. New York: Guilford Press.

Rourke, B. P. (1995). The science of practice and the practice of science: The scientist-practitioner model in clinical neuropsychology. Canadian Psychology, 36, 259-287.

Rourke, B. P. (2000). Neuropsychological and psychosocial subtyping: A review of investigations within the University of Windsor laboratory. Canadian Psychology, 41, 34-50.

Rourke, B. P., Ahmad, S. A., Collins, D. W., Hayman-Abello, B. A., Hayman-Abello, S. E., & Warriner, E. M. (2002). Child-clinical/pediatric neuropsychology: Some recent advances. Annual Review of Psychology, 53, 309-339.

Rourke, B. P., & Conway, J. A. (1997). Disabilities of arithmetic and mathematical reasoning: Perspectives from neurology and neuropsychology. Journal of Learning Disabilities, 30, 34-46.

Rourke, B.P., & Fuerst, D. R. (1991). Learning disabilities and psychosocial functioning: A neuropsychological perspective. New York: Guilford Press.

Rourke, B. P., Hayman-Abello, B. A., & Collins, D. W. (2003). Learning disabilities: A neuropsychological perspective. In R. S. Schiffer, S. M. Rao, & B. S. Fogel (Eds.), Neuropsychiatry (2nd ed., pp. 630-659). New York: Lippincott, Williams, & Wilkins.

Rourke, B. P., van der Vlugt, H., & Rourke, S. B. (2002). Practice of child-clinical neuropsychology: An introduction. Lisse, The Netherlands: Swets & Zeitlinger.

Tsatsanis, K. D., Fuerst, D. R., & Rourke, B. P. (1997). Psychosocial dimensions of learning disabilities: External validation and relationship with age and academic functioning. Journal of Learning Disabilities, 30, 490-502.

Warriner, E. M., Rourke, B. P., Velikonja, D., & Metham, L. (2003). Subtypes of emotional and psychosocial sequelae in patients with traumatic brain injury. Journal of Clinical and Experimental Neuropsychology, 25, 904-917.

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