I am looking for information about differential diagnosis between language disorders and learning disabilities. I have been receiving questions regarding diagnosis and services and how to distinguish between S/L and LD. I would appreciate information on t
I can address some generalities on this topic, but each child requires individual assessment and management, and many of the categories "overlap" based on the particular child involved and the training and background of the professional assessing and managing the child!
I believe we have to distinguish whether we mean Specific Language Impairment (SLI) or Speech-Language deficits (SL) or Learning Disability (LD).
Traditionally, SLI children were diagnosed when there was decreased performance on standardized measures of language development (morphology, syntax, semantics, comprehension, etc.) of at least 1.5 SD below the mean (M=100, SD=15 for most tests). SLI children were supposed to have normal intelligence, and not supposed to have behavior or psychological deficits.
As experience shows, the SLI label does not really account for the deficits witnessed in these children as it is almost impossible to find a "pure specific language impairment" or what is called by linguists a "grammatical SLI." In general, these children have slightly depressed IQs (with no sufficient differences between verbal and performance IQs), they have difficulties with math (not quite failing it, but requiring a lot of time to process) and are poor readers.
SL children, with speech-language problems only, can have a variety of deficits in specific areas of language production or comprehension and these areas will be addressed according to the findings on the standardized tests.
LD children show a different profile. One core difference is the spread between verbal IQ and performance IQ, even when the full IQ is within normal range. Therefore, you have to identify very specific areas of deficits in order to help these children learn.
For example: there might be a specific language-based learning disability, in which a child will do well in all areas of performance and even in math, as long as it doesn't involve "word based math problems" - then we will see a break down in performance and treatment of these children will focus on helping them process language.
Dr. Zaretsky has been in the field of Communication Disorders for 10 years. She holds MS in Communication Disorders and Ph.D. in Developmental Psychology. She is a faculty member at the Department of Communication Disorders at Umass, Amherst, and can be reached at firstname.lastname@example.org