Monday, 21 November 2011

OCD and autism: symptom overlap or discrete conditions?

Hoarding and the personal/familial effects of hoarding behaviours has been very briefly mentioned on this blog. The various elements to hoarding behaviour based on things like compulsion and explanations on the 'functionality' of hoarded objects makes for quite a complicated condition.

A recent paper by Pertusa and colleagues* asked a few questions about whether: (i) hoarding behaviours might be related to certain autistic traits and (ii) how hoarding behaviour in cases of autism might manifest with regards to comorbidity. Their results were complicated in that yes, those engaging in hoarding behaviours showed a greater degree of autistic traits compared to asymptomatic controls. Hoarding behaviour in this non-autism group were however also reportedly related to the presence of obsessive-compulsive traits. By comparison, hoarding behaviour noted in a group diagnosed with autism seemed to be unrelated to any comorbid obsessive-compulsive issues.

On the back of such research I want to talk about the association between OCD (Obsessive Compulsive Disorder) and autism, and in particular, OCD as a discrete clinical diagnosis in cases of autism, where many people might assume that some of core traits associated with autism are/overlay with OCD. The traits in question are those associated with the repetitive behaviour domain which in some cases, may seem to develop certain 'obsessional' or 'compulsive' aspects to them. So for example, talking about one particular subject or at least consistently steering a conversation towards that topic, and the insistence on following a certain routine (with often notable anxiety if not carried out to specification). Whilst there is little doubt that such repetitive behaviours can become compulsive and obsessional in nature, the question posed is: do they fit the criteria for OCD as a discrete diagnosis?

As you might imagine there is no straight-forward, universal answer to this question, but there are some clues. Clues which seem to suggest that rather than assigning every single behaviour seen in autism to autism, there are some presentations which may merit additional investigation and potential discrete diagnosis based on their frequency and severity. I suppose I have covered similar ground in my previous posts on PTSD and autism and also suggesting that at the moment, autism does not seem to confer any protection against developing other conditions during my various musings on autism and things like ADHD.

It may be worthwhile showing you the diagnostic criteria for OCD in both current versions of DSM and ICD. I wouldn't really do the diagnosis justice if I tried to describe OCD in just a few words, but the watch words are (a) obsession/s - the same images, ideas or impulses being thought about again and again, (b) compulsion/s - repetitive behaviours or mental acts often applied quite rigidly and (c) anxiety and distress - either caused by such obsessions and/or compulsions or as a result if certain actions aren't carried out.

For those with some experience of autism, you can perhaps see how OCD and autism might, in some cases, be quite difficult to separate out. Indeed much of the research literature on OCD and autism spectrum conditions has a pretty hard time teasing out the differences (here and here).

A recent study by van Steensel and colleague (full-text)** however looking at anxiety-related conditions presented concurrent to autism reported that 17% of people with an autism spectrum condition also presented with a verifiable DSM-IV diagnosis of OCD. The strength of this study lay in the fact that it was a meta-analysis and hence combines to form quite a large participant sample (N=2000+). Aside from going back to that 'not everything is caused by autism' notion, there are a few other important consequences of these findings, not least the various strategies potentially available to alleviate the obsessive/compulsive aspects to OCD and the resultant anxiety. Some of the main strategies are detailed here (noting that I am not offering any advice or guidance). Given the recent post on SSRIs and autism, I might perhaps be a little cautious about their use when autism is co-morbid. Having said that, it is not outside the realms of possibility that those 'best-responders' to SSRI-based pharmacotherapy might be those people with autism with significant OCD issues. A case of pharmacotherapy not targeting the core symptoms but rather the peripheral ones which then impact on core presentation (as argued previously here).

There are no easy or straight-forward answers to the autism-OCD link. What this and other research does however point to is that when it comes to the assessment of autism currently made, and those to be made in future when schedules like DSM-V are enacted, clinicians need to be vigilant for lots of different behavioural pointers. These may not necessarily be just those related to the presentation of autism; mindful that conditions like OCD can also develop at later stages.

* Pertusa A. et al. Do patients with hoarding disorder have autistic traits? Depression & Anxiety. November 2011.

** van Steensel FJA. et al. Anxiety disorders in children and adolescents with autistic spectrum disorders: a meta-analysis. Clinical Child & Family Psychology Review. 2011: 14: 302-317