1. School of Psychology, Speech and Hearing University of Canterbury Christchurch New Zealand
2. Department of Psychological Medicine University of Otago Christchurch New Zealand
3. Clinical Research Unit Canterbury District Health Board Christchurch New Zealand
4. Department of Psychiatry University of North Carolina Chapel Hill North Carolina USA
5. Department of Nutrition University of North Carolina Chapel Hill North Carolina USA
6. Department of Medical Epidemiology and Biostatistics Karolinska Institutet Stockholm Sweden