Sir, I am delighted to see the publication of a series of articles about special care dentistry in the BDJ. However, I was surprised to see that three references in Access to special care dentistry, part 6. Special care dentistry services for young people (BDJ 2008; 205: 235–249) came from Wikipedia. Whilst I accept that information on pica may be difficult to find, and so Wikipedia might have been accessed as a last resort, there is a wealth of information about obsessive-compulsive and bipolar disorders available from more reputable sources.

For example, they are covered by the excellent range of clinical guidelines produced on mental health and behavioural conditions by the National Institute for Health and Clinical Excellence (http://www.nice.org.uk). Additionally, the 'Overcoming' series of books (http://www.overcoming.co.uk) is recommended by several local NHS 'Books on Prescription' schemes, and deals with these mental health difficulties.

I would most certainly turn to either of these sources before using Wikipedia.