To the Editor: In a report regarding the National Institute of Mental Health (NIMH) study about the longitudinal course of affective disorder (1), David A. Solomon, M.D., and colleagues concluded that the risk of recurrence progressively increases with each successive affective episode. It is remarkable that the individual propensity toward recurrence is taken into account in the analyses (mixed-effect, grouped-time survival analyses). To our knowledge, only our previous study (2) has done this as well. In that study, so-called frailty models were used to analyze the effect of prior episodes on the risk of recurrence in unipolar and bipolar disorder. An episode effect was demonstrated in bipolar affective disorder in general and in women with unipolar disorder. However, for unipolar men, no effect of prior episodes was found when the effect was adjusted for frailty.