Professor Digby Tantam on autism, anxiety and OCD

Professor Digby Tantam has worked as a psychiatrist specialising in autism spectrum conditions (ASC) for over thirty years. Here he looks at co-morbidities and how clinicians can better support individuals through the diagnostic process.

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Autism, anxiety and OCD

The real change I've seen in the field of autism in the last thirty years is in the understanding of the condition. It took a long time for people to accept it could be an adult condition. People weren't aware of Aspergers and awareness has really grown around the difficulties individuals with Aspergers have, especially when relating to possible co-morbidities with conditions such as anxiety and Obsessive Compulsive Disorder.


In my clinical experience anxiety is much the biggest co-morbidity with autism. Anxiety can arise as a result of how individuals with an ASC have been treated or from their difficulties around understanding non-verbal communication. It affects as much as half of adolescents with Aspergers and can severely impact on quality of life and emotional well-being.

Anxiety disorders are characterised by:

  • Panic
  • Trouble sleeping
  • Avoiding situations which involve lots of people
  • Shortness of breath
  • Inability to think clearly

The complication in the autism/anxiety disorder co-morbidity is that people with autism often don't display anxiety through facial expressions and wouldn't necessarily spontaneously share their anxiety. The social cues that clinicians often rely on may not always be present. I'm shocked that even now I can still miss peoples' anxiety issues, as if the body language is not giving you that impression it's hard to tell.

As a professional one must ask direct and specific questions of individuals on the spectrum as those often achieve direct answers about the individuals needs and concerns.

Clinicians should also be aware that individuals behaviour will be different in other environments as it might be in your unfamiliar clinic. We must ask them questions about what makes them happy to reduce their anxiety about the appointment before we attempt to ask questions about their challenges.

Anxiety is a reassuring diagnosis to receive as individuals know that it's a diagnosis that can be dealt with and managed.

Obsessive Compulsive Disorder (OCD)

OCD is twice as frequent in individuals with autism as it is in the general population. A diagnostic complication here is that OCD is characterised by ritualistic behaviour and rituals are often common in autism. In Aspergers rituals become more prominent. Many people with Aspergers can develop OCD individually but many get very ritualistic but don't have OCD.

The way of deciding whether it's ASC or OCD at the root of the ritual is simple. In OCD people don't find rituals enjoyable or helpful yet are still driven to do them: some may tap a table several times because they are afraid a catastrophe will happen if they don't. Whereas an individual who has growing rituals that they find comforting and enjoyable but which they feel they can stop wouldn't have OCD.

When working with an individual with a co-morbidity of autism and OCD we must give attention to both conditions. With the OCD we must help the individual to reduce their anxiety (the root cause of the rituals) first before we attempt to manage the rituals (response prevention). Response prevention works best when people with Aspergers say their anxiety is at a manageable level.

Dealing with a diagnosis

When telling an individual about their co-morbidity I'd explain exactly what I mean by each diagnosis. For example, with an autism spectrum diagnosis I'd refer back to the relevant areas of need that they have shared with me that have led to me giving them that diagnosis. In the case of co-morbidity I'd then explain that the autism may not be the cause of all of their current difficulties and I'd outline what the cause of those might be. Clinicians must be clear with individuals on the spectrum to ensure that they aren't left with confusion about their diagnoses. We have to be careful that we don't leave clients reeling when they leave. Clinicians must frame diagnoses in a way that empowers individuals to feel that they can tackle their needs, prioritise what needs must be met first and make a plan.

Author: Professor Digby Tantam, Honorary Consultant Psychiatrist and Psychotherapist for Sheffield Health Care NHS Foundation Trust and an Emeritus Professor at the University of Sheffield.

Date added: 21st January 2014