Inclusion and exclusion criteria
Eligible for inclusion in all three studies were women without previous
psychiatric diseases or use of antidepressants or psychotropic drugs
during a four- or five-year period prior to the study period. Pregnant
women were excluded in all three studies. Women with previous thrombosis
or cancer were excluded in study 1 and 3 and controlled for in study 2.
Study 33 in addition excluded all women having used
hormonal contraception before the age of 15 years. The argument was that
women starting use of hormonal contraception before 15 years often have
medical conditions indicating that use. Study 3 also excluded women who
during the study period developed other mental disorders, also if at the
same time getting a depression diagnosis.