Co-morbid Anxiety in Autism Spectrum Disorders

Hsiao-Min Grace Hsu1, Deborah Pearson, Ph.D.2, Rosleen Mansour, M.S.2, and Katherine Loveland, Ph.D.3. (1) College of Medical Science, Fu Jen Catholic University, 510 Chung Cheng Road, Hsingchuang, Taipei County 24205, Taiwan, (2) Psychiatry & Behavioral Sciences, University of Texas Health Science Center, Houston, U.T.M.S.I.- 1300 Moursund Street, Houston, TX 77030, (3) University of Texas Medical School, University of Texas Health Science Center, Houston, U.T.M.S.I. - 1300 Moursund Street, Houston, TX 77030

Background:

Autism Spectrum Disorders (ASD) involve impairments in social-emotional skills, communication, and repetitive behaviors. Many persons with ASDs also have symptoms of anxiety, resembling OCD, since individuals with ASD and those with OCD both have repetitive or compulsive behaviors.

Objectives:

This study had three goals: 1) classifying youth with ASD into those with and without clinically significant symptoms of OCD, 2) determining if those with  ASD and OCD differ in anxiety from those without OCD, and 3) examining group differences in repetitive/stereotyped behaviors.

Methods:

Participants were 106 children and adolescents with (ADI-R/ADOS) ASD aged 7-18 years, IQ ³ 40, assessed with the Diagnostic Interview for Children and Adolescents (DICA) and classified significant symptoms of Obsessive Compulsive Disorder (OCD).  33 met criteria for OCD and 73 did not. These groups were both >80% males, with no significant differences in age and IQ. Differences in anxiety were examined using the Conner’s Parent Rating Scale-Revised (CPRS-R). Differences in repetitive/stereotyped behavior were compared using the ADI-R.

Results:

On the CPRS-R, the ASD-OCD group had significantly higher anxiety and shyness than the ASD-only group (t (72) =2.69, p=.003), and more of them met criteria for Specific Phobia (c2(1) =18.38, p<.001) and Social Phobia (c2(1) =8.18, p<.02).

The ASD-OCD group also had significantly greater compulsions or rituals (t (101) =3.47, p=.001) and difficulties with minor change (t (98) =2.97, p=.004).

Conclusions:

This study identified a subset of individuals with ASD who met criteria for OCD and who also had more anxiety, phobias, compulsions, and difficulties with change.  These results suggest there is a significant subgroup of persons with ASD who can be considered to have co-morbid OCD, and that these persons exhibit greater symptoms of anxiety and anxiety disorders more generally. Further studies should address specific risk factors for co-morbid OCD in persons with ASDs.