Ks. Kendler et al., Are there sex differences in the reliability of a lifetime history of major depression and its predictors?, PSYCHOL MED, 31(4), 2001, pp. 617-625
Background. Although lifetime major depression (LTMD) is assessed with only
moderate reliability in community samples, some predictors have emerged fo
r 'reliable' LTMD. Given the large impact of sex on risk for LTMD, it is of
interest to know if there are sex differences in the reliability of LTMD a
nd its predictors.
Methods. A total of 5603 members of male-male and male-female twin pairs fr
om a population-based registry were interviewed twice with a mean inter-int
erview interval of 19 months. LTMD was assessed on each occasion using DSM-
III-R criteria. Univariate and multivariate logistic regression analyses we
re used, combining forward and back-prediction.
Results. The long-term test-retest reliability of LTMD was moderate (kappa
= +0.48) and did not differ significantly between males and females. In a m
ultivariate model, the significant predictors of a stable diagnosis of LTMD
, none of which differed across sex, were younger age at onset, older curre
nt age, history of treatment, increasing number of symptoms, level of impai
rment or level of distress, longer duration of episodes, higher current lev
el of depression and the presence during the depressive episode of sad mood
, weight loss, hypersomnia or fatigue. Using these variables, it was not po
ssible to predict 'stably diagnosed' LTMD with both high sensitivity and hi
gh specificity.
Conclusion. In community samples, LTMD is diagnosed with moderate reliabili
ty. Although diagnostic stability can be predicted by variables related to
severity, distress and treatment-seeking (probably acting to make depressiv
e episodes more 'memorable'), highly accurate prediction of stably diagnose
d cases is not possible. Long-term recall is also significantly influenced
by current symptoms. Neither the stability of LTMD nor its predictors diffe
r in men and women.