A dysfunctional system

Two letters in the September issue highlighted the diagnosis of developmental disorders; Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD). In both cases, the disorders were referred to as if they were unitary conditions with varying presentations; could be diagnosed accurately (even if they often weren't); and where diagnosis gave access to support and treatment.

I have three comments.

Firstly, many developmental disorders, including ADHD and ASD, are syndromes – hypothesised unitary conditions where certain signs and symptoms co-occur, presentation varies between individuals, but the cause is unidentified. What is widely overlooked is the 'fan-in-fan-out' model proposing that individual differences are due to similar signs and symptoms arising from different causes in different people. (See Coleman and Gillberg's work for evidence in the case of ASD). 

Secondly, if a syndrome has different causes in different people, an 'accurate' diagnosis is impossible, unless the cause is identified. The best you can get is agreement on the similarities to the syndrome's criteria.

Lastly, it's all too easy to assume that because services should be offering appropriate support, they are actually doing so. Despite public services in the UK being based on needs rather than the cause of the needs, a formal diagnosis can nonetheless add weight to requests for support – but sadly the support is in short supply. Families hoping that diagnosis will open the door to support are at risk of disappointment. On the contrary, as one paediatrician said to me; 'A diagnosis can provide some protection from the system'.

The authors of the letters are clearly doing their utmost to improve the lives of their patients, but they're working in a wider system that's seriously dysfunctional, and need to be aware of that.

Sue Gerrard