OCD behaviours in autism are a subject of debate. Are they a co-morbid condition, or an integral feature of the autistic condition for many with autism? Interesting research states the following:
http://apt.rcpsych.org/content/7/4/310.full
“Obsessive compulsive disorders (DSM-IV)
The core features of obsessive–compulsive disorder (OCD) are recurrent and persistent thoughts, impulses or images that are experienced at some time during the disturbance as intrusive and inappropriate and that cause marked anxiety or distress. The individual recognises that these are a product of his or her own mind. Compulsions involve repetitive behaviours or mental acts that a person feels driven to perform to reduce stress associated with some dreaded event or situation. An adult can recognise that they are excessive or unreasonable, but children cannot (American Psychiatric Association, 1994).These phenomena, including the urge to count and manipulate numbers, to repeat the same action over and over, are similar to the repetitive routines associated with Asperger syndrome. Individuals with both conditions display ritualistic behaviour and resistance to change. Where they differ is that persons with Asperger syndrome have obsessive interests that are not experienced as ego-dystonic and, indeed, are often enjoyed. Baron-Cohen (1989) was critical of the use of the term obsession in persons with autism because the subjective phenomena of resistance to repetitive activities could not be discerned in autism. He suggested instead the phrase ‘repetitive activities’. OCD generally has a much later onset and lacks the poor social emotional reciprocity, empathy problems and social skills difficulties of people with Asperger syndrome (Szatmari, 1998). Detailed analysis of current symptoms and an early developmental history are the key to making a correct diagnosis.
Clearly, the differentiation of Asperger disorder from other conditions is complex because of the many possibilities for misdiagnosis. The key to correct diagnosis is a precise early developmental history, with a systematic discussion of all the criteria set out for Asperger syndrome (Wing, 1981; Gillberg, 1991) or Asperger disorder (American Psychiatric Association, 1994). Assessment instruments such as the ADI–R may be useful in establishing diagnosis. A multi-disciplinary team approach is critical, and diagnosis from a solely neurological, speech and language or educational point of view must cease if families are to be spared confused partial diagnoses.”
Clearly, it’s highly questionable that OCD should be considered a separate diagnosis that is in addition to the ASC diagnosis, so is it actually a trait that is a core feature in a significant amount of individuals with ASC. Especially so, when you consider that true OCD, usually starts later, than OCD behaviours in autism may present:
“OCD affects males and females equally, and on average begins to affect people during late adolescence for men and during their early twenties for women.”
Therefore, children who show OCD behaviours younger than this, who are in fact on the autistic spectrum, should be evaluated with extra care during their ASC assessment so that OCD traits do not deflect from their ASC traits and they end up misdiagnosed. Clinicians need to have full training and awareness of the existence and frequence of OCD behaviours in autism.
I definitely have OCD behaviours, I colour-match clothes pegs, I go back and re-check I have locked the front door even when I know I did lock it, I have to do it every time, and I am compelled to check that I didn’t leave my bag or belongings behind when I get up to leave somewhere. When I was a teenager I used to have to step on certain parts of paving stones as I walked. None of this is about me feeling something bad will happen if I don’t do it, it is a compulsion which no doubt is about control. As an Aspie, life is chaotic and confusing, so somewhere in my brain, I clearly need to control my environment as much as possible. It doesn’t rule my life, but it does affect it, because probably if someone tried to force me not to carry out my checks and organising, I might start heading for a meltdown!
Hoarding is a known type of OCD, but then collecting things is common on the autistic spectrum so where does one start and the other end? Females are often known to like collecting handbags and shoes for instance. I do this, but to quite an extreme. I have many handbags that I have matching shoes for, all of which are neatly stored in stacked shoe containers, and most of which have never been worn. I like these things, I want them, I feel compelled to get them, but then I don’t use them. Likewise, I collect beauty gadgets (I sometimes think I own enough that I could set up my own beauty business with them!) and many never get used and are surplus to requirements. I also have a strange fascination with cleaning implements such as vacuum cleaners. I don’t understand why. I am always behind with housework so it’s not as if I am an OCD cleaning-freak. I read about the features of vacuum cleaners and get a thrill when I see a new vacuum cleaner product, I’m currently very interested in robot vacuums! These fascinations, which can develop into special interests could look like OCD behaviours, but merge into autism spectrum behaviours.
New edit: This piece of research questions whether there is a “putative OCD-autistic disorder, which should be studied in greater detail.” http://www.ncbi.nlm.nih.gov/pubmed/12587149
New edit: This research identifies that OCD and autism share genetic roots and “people with autism are twice as likely to receive a diagnosis of OCD and people with OCD are four times as likely to also have autism” https://spectrumnews.org/news/sweeping-study-underscores-autisms-overlap-with-obsessions/
Thought for the day:
Planet Autism Blog 
My OCD has always seemed to me to be a symptom of my autism, like a sore throat is a symptom of a cold, one among many.