Comorbidity is described as a situation where two or more psychological or educational disorders or syndromes occur together. The exact nature of the relationship between comorbid conditions is a matter of some debate in the research literature. It is particularly difficult to determine whether one condition causes or is simply related to another.

It is important for school psychologists to understand the nature of comorbidity. This will better [Page 102]enable them to conduct a thorough evaluation, develop a treatment plan, and recommend appropriate interventions. When disorders covary in children, the school psychologist can address the specific needs of each disorder.

A large body of studies supports a comorbid relationship, as high as 70%, between learning disabilities and attention deficit disorder (ADD) (with or without hyperactivity). Children diagnosed ...