Mental illness in sibships of two and three.
D000328:Adult; D000367:Age Factors; D001722:Birth Order; D003863:Depression / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000235:genetics*; D009497:Neurotic Disorders / Q000235:genetics; D011618:Psychotic Disorders / Q000235:genetics; D012737:Sex Factors; D012801:Sibling Relations