Is it possible for an individual to have more than one learning disability at the same time? Indeed, it is possible, and in fact is even common. When a person is diagnosed with two or medical conditions at the same time, the diseases or disorders are said to be comorbid. That is, a condition exists simultaneously with, and independent of one or more other conditions.
Studies have shown that a given learning disability is often comorbid with one or more other learning disabilities. The overall rate of comorbidity is 40%. That is, 40% of the individuals diagnosed with a learning disability also have been simultaneously diagnosed with another, separate, learning disability. ADHD has even higher rates of comorbidity. The comorbidity of ADHD with other disorders is between 60% and 80%. Reading disability (RD) and math disability (MD) also have very high rates of comorbidity with both occurring in 30 to 70 percent of individuals with either disorder. Evidence suggests that individuals with comorbid learning disabilities may be more disadvantaged that individuals having a single disorder.