Question
If a child is having a difficult time following oral directions within the classroom, how can we differentially diagnose APD from ADD/ADHD, without having expensive APD testing done?
Answer
While any suspected diagnosis cannot be confirmed without the administration of specific assessment batteries, certain behavioral differences between the child with ADD/ADHD and the child with APD can often provide important and telling clues for true differential diagnosis. ADD/ADHD will typically evidence a detrimental impact across both verbal and non-verbal communication acts, whereas APD is predominantly expressed in only auditory-verbal demand areas such as with the inability to follow verbal directives that you describe. For example, a child with ADD/ADHD may have difficulty attending to visual stimuli (as well as auditory), completing independent "language-free" seatwork, and even maintaining focus on recreational activities. There is only "start" and no "finish" so to speak.....tasks are seldom seen through to completion (even those which could be accomplished without the understanding of verbal directions via watching a classmate and copying what they do). ADD/ADHD will most frequently effect a negative impact across multiple subject areas (including non-academic parameters) and children affected seldom ask for clarification or other types of repair unless specifically requested to do so. These children are able to follow directions (even complex and multi-step ones) when provided with adult support to keep them on task.
The child with APD will often show difficulty with semantic relationships, linguistic closure tasks, integrative language applications, and complex linguistic structures (e.g., subordinate clauses) independent of verbal instruction formats. They typically show challenge with acting on verbal stimuli that requires fine auditory discrimination, auditory figure-ground skills, auditory closure tasks, or sustained auditory attention in the presence of noise (they do quite well in quiet when a child with ADD/ADHD may not). These children are able to follow directions when provided with adult support to externally filter auditory distractions or to provide specific emphasis/prosody to differentiate key words from function or filler words. The child with ADD/ADHD does best with repetition of instruction; the child with APD does best with restatement and rephrasing of instruction. The child with APD must learn to separate, decode, and attend to auditory stimuli; the child with ADD/ADHD must learn to separate, decode, and attend to both visual and auditory stimuli.
Suzanne Swift is a speech-language pathologist specializing in pediatric issues at Eastern New Mexico University. Most of her practice has centered on service delivery to children and adolescents in Family-Infant-Toddler programs and in public school systems in New Mexico and Texas. She has a particular interest in differential diagnosis, intervention methodologies, and in designing effective communication systems for children having sensory impairments of all types.
