1. Kingís College London, National Addiction Centre, Institute of Psychiatry, London, UK
2. MRC Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, London, UK
3. National Addiction Centre, Institute of Psychiatry, London, UK
4. Neuroendocrine Laboratory, GKT School of Medicine, Guys Campus, London, UK
5. Analytical Unit, St Georgeís Hospital Medical School, London, UK