Oral contraception and serious psychiatric illness: absence of an association.

The incidence of serious psychiatric illness, as measured by first referral to hospital for specialist advice and treatment, has been investigated among 16,746 women taking part in the Oxford Family Planning Association contraceptive study. Of these women, 9,504 were recruited while using oral contraceptives, 4,144 while using a diaphragm and 3,098 while using an intrauterine device. The results are reassuring with respect to oral contraceptive use. First referral rates per 1000 woman-years of observation in the oral contraceptive, diaphragm, and intrauterine device entry groups were 3.0, 2.6, and 2.8 respectively for non-psychotic psychiatric disorders and 0.46, 0.43 and 0.53 respectively for psychotic disorders. Attempted suicide occurred only 40% as often amongst diaphragm users as amongst users of oral contraceptives or intrauterine devices; this finding presumably reflects the characteristics of women who choose the diaphragm as their birth control method.