not consistent across interviews and screening items for psychosis were not included; the ability to assess accurately these less common criteria is difficult in large-scale community settings. Therefore, it is possible that a small number of individuals with a primary diagnosis of bipolar disorder or schizophrenia are included in the case group. If multiple cases were present within families then one case was selected in the following order of preference: age of onset <31 years, multiple episodes of depression, co-morbid anxiety disorders and high neuroticism score. Unrelated controls were selected as genotyped individuals from families in which no individuals qualified for diagnoses of MDD or anxiety disorders. If multiple controls were available from a family, the individual with the lowest neuroticism score was preferentially selected, otherwise an individual was selected at random.
