1. Department of Psychiatry; Virginia Institute for Psychiatric and Behavioral Genetics; Virginia Commonwealth University; Richmond Virginia
2. School of Community and Social Medicine; University of Bristol; Bristol United Kingdom
3. Department of Statistics; Ankara University; Ankara Turkey
4. Mental Health Sciences Unit; University College London; London United Kingdom
5. MRC, Social, Genetic and Developmental Psychiatric Centre; King's College London Institute of Psychiatry; London United Kingdom