I welcome the fact that my letter on psychopathic personality disorder (12 November) generated further debate. But Michael Howlett's response (Letters, 26 November) missed crucial points. I agree that the psychiatric profession does not always speak with one voice, but it is important to look at available evidence.

There is no convincing evidence that antipsychotic medication significantly benefits people with psychopathy, although many such agents can be sedative and reduce arousal. Nevertheless, these are basically side-effects, and it is interesting to see a figure like Mr Howlett apparently advocating more widespread use of such drugs for unlicensed indications.

As far as psychological therapies are concerned, which particular branch of psychotherapy has he in mind? It encompasses a wide range of different models and techniques, and 'psychotherapists' do not constitute a single profession, being drawn from psychology, psychiatry, nursing and so forth. Mr Howlett wants a reconfiguration of services targeting resources early in childhood and adolescence. But it would seem irresponsible to advocate such a change without substantial evidence. The most sensible way would be to set up experimental treatment units - which the Butler committee recommended for adults with psychopathic personality disorder, although it did suggest these should be within the penal system. It suggested suitable ideas for such units might come from a spectrum of disciplines; the assumption that the solutions (and responsibility) lie solely with psychiatrists was home secretary Jack Straw's, not mine. Until society takes responsibility for an informed debate, we will continue to be stuck in a 'conceptual wasteland', blaming anyone who dares even attempt to do anything about it.

H W Griffiths

Medical director/consultant psychiatrist

Northumberland Mental Health trust