It is possible that change in depression symptoms may not necessarily co-occur with change in personality factors, and given that self-criticism as a personality factor has been shown to lead to depression, this could be problematic. One study found that positive change in depression occurred before any change in self-critical perfectionism. The authors of this study suggested that this has implications for deciding how long to provide treatment. If treatment ends as depression fades away, the underlying personality characteristics that affect depression may not have changed. In such a case extending treatment beyond the point when positive change is seen in depression symptoms may give the best results. This same study also found that levels of perfectionism (which is related to self-critical personality) predicted the rate of change in depression status.