 In one study, 2 of 3 people with 18p- had an anxiety disorder, 1 of 3 had a communication disorder, and 1 of 3 had a motor skills disorders, and 1 of 3 had a stereotypic movement disorder.Additional research with a larger number of subjects is necessary to confirm these findings.Cognitive ability in individuals with 18p- varies widely, with most falling in the mild to moderate range of impairment, though there have been some reports of people with impairment in the severe to profound range.