Restricted Interests: Obsessions, "Special Topics," and Attention Deficits

Date First Published: April 2, 2007
Date Last Updated: August 25, 2009

Restricted and repetitive interests and activities are one of the key features of autism.1  Watching a fan spin around for hours; flipping the flag on a toy mailbox up and down again and again; taking a spoon or other inanimate object everywhere as though it were the most special thing in the world; repeatedly lining up Thomas the Tank Engine trains in the same order; poring over lists and facts about a favorite topic, whether it be African insects, a sports team or Star Wars – all of these are examples of the intense and restricted focus a person with an ASD can possess.  Yet, the same person may have a terrible time focusing on something imposed by the outside world, like a therapy exercise or schoolwork.

Imagine a severely affected child who, desperate to get back to opening and closing the front door of a dollhouse, throws a tantrum when his mom tries to get him to focus on dressing. Imagine another child who cannot sit still and concentrate on a “fill-in-the-blank” homework sheet for more than a minute at a time because he keeps “zoning out," driven or drawn to that one topic that fascinates him.

Observers of such behaviors have often called them “obsessions” or “compulsions," although the use of these words to describe them has been challenged.2   After all, a compulsion has an anxious, driven quality. Think of someone with obsessive-compulsive disorder (OCD) who constantly washes their hands, not because they want to, not because it feels good, but because they have to, even if it makes them feel out of control and miserable. This does not seem to describe how people with ASDs experience their activities or interests. On the one hand, we should be careful not to assume such activities are actually satisfying, especially when lower functioning individuals cannot tell us how they experience them, or when they may not have the capacity to self-reflect about them at all.3  On the other hand, higher functioning individuals do express enthusiasm about their special topics, sometimes even building careers and identity around them.4

It is interesting to note that researchers trying to assess if people with ASDs do in fact have obsessions and compulsions (as these are defined by psychiatrists) were careful to instruct their participants that “something one is very interested in” did not equate with an obsession in the context of the study.5  Clearly, they were distinguishing between a beloved “special topic” a person can’t wait to talk about and an “I-want-to-stop-and-I-can’t” compulsion that a person despises and struggles against. The researchers did find that some of their participants with an ASD had true obsessions or compulsions, but stressed that these should be “carefully distinguished from other common repetitive behaviors and special interests in ASDs.” 6

Researchers have found that children on the autism spectrum who perform a great deal of repetitive behaviors are more likely to have parents with obsessive-compulsive traits, or even actual obsessive-compulsive disorder.7,8

Problems of attention and focus have also often been observed in children with ASDs,9  and it has been suggested that there is some overlap between attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders that may be genetic in origin.10   Whatever the case, it is clear that individuals with ASDs tend to over-focus on some things while shutting out or ignoring others.

Parents and other supporters obviously cannot permit a person with an ASD to spend every waking hour on their special object, topic, or activity. On the other hand, it is precisely through those “favorite things” that a family member or other supporter may find a way to build a connection with a person who has an ASD.


  1. American Psychiatric Association. (2004). Diagnostic and statistical manual of mental disorders (4th ed., rev.). Washington DC: Author.
  2. Baron-Cohen, S., (1989). Do autistic children have obsessions and compulsions? British Journal of Clinical Psychology, 28(3), 193-200.  Abstract
  3. McDougle, C.J., Kresch, L.E., & Posey, D.J. (2000). Repetitive thoughts and behavior in pervasive developmental disorders: Treatment with serotonin reuptake inhibitors. Journal of Autism and Developmental Disorders, 30(5), 427-435.  Abstract
  4. Grandin, T. (2006). Thinking in pictures: My life with autism. (Exp. ed.) New York: Vintage Books.
  5. Russell, A.J., Mataix-Cols, D., Anson, M., & Murphy, D.G.M. Obsessions and compulsions in Asperger syndrome and high-functioning autism. (2005) British Journal of Psychiatry, 186, 525-528. (pg. 526)  Abstract
  6. Russell, A.J., Mataix-Cols, D., Anson, M., & Murphy, D.G.M. Obsessions and compulsions in Asperger syndrome and high-functioning autism. British Journal of Psychiatry, 186, 525-528. (pg. 527)  Abstract
  7. Abramson, R.K., Ravan, S.A., Wright, H.H., Wieduwilt, K., Wolpert, C.M., Donnelly, S.A., Pericak-Vance, M.A., & Cuccaro, M.L. (2005). The relationship between restrictive and repetitive behaviors in individuals with autism and obsessive compulsive symptoms in parents. Child Psychiatry and Human Development, 36(2), 155-165.  Abstract
  8. Hollander, E., King, Audrey, Delaney, K., Smith, C.J., & Silverman, J.M. (2003). Obsessive-compulsive behaviors in parents of multiplex autism families. Psychiatry Research, 117, 11-16.  Abstract
  9. Volkmar, F.R., & Klin, A. (2005). Issues in the classification of autism and related conditions. In F. Volkmar et al. (Eds.), Handbook of Autism and Pervasive Developmental Disorders (pp. 5-41). Hoboken, NJ: John Wiley & Sons.
  10. Smalley, S.L., Kustanovich, V., Minassian, S., Stone, J.L., Ogdie, M.N., McGough, J.J., McCracken, J.T., MacPhie, I.L., Francks, C., Fisher, S.E., Cantor, R.M., Monaco, A.P., & Nelson, S.F. (2002). Genetic linkage of attention deficit/hyperactivity disorder on chromosome 16p13, in a region implicated in autism. American Journal of Human Genetics, 71, 959-963.  Abstract
These archived articles were originally published as part of the Interactive Autism Network (IAN) research project. 
The project is closed and no longer accepting participants.

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