Prodromal period. It becomes urgent and may need to be more drastic if the prodromal stage is comparatively short. Only two studies to date investigated the length of the bipolar prodromal period. Both are retrospective studies, and hence, the findings have to be treated with caution. One study reported the mean number of days for mania prodromes was 20.5 days, rande 1 to 83 days(Molnar et al., 1998) Another study reported it as 29 days, range 1 to 84 days (Smith & tarrier, 1992). In terms of depression, molnar et al. (1998) reported that the mean number of days for depression prodromes was 11 days (range 2-31) and smith and tarrier (1992) reported it to be 19 (range 3-365)
There observations are noteworthy. First, across studies, it was found that there was wide individual variation in the duration of both manic or depression prodromal stages. Secondly, these studies typically have sample sizes of about twenty subjects, and hence, their findings should be treated with caution.