I am a strong advocate of the use of cognitive therapy in chronic and residual depressive disorders. I am therefore the last to disagree with the comments of Ito and colleagues that there is real benefit in providing psychosocial treatments to individuals with residual depressive symptoms. My comment on social functioning was not meant to under-estimate the benefits, but paid heed to two factors. First, although individuals who received cognitive therapy undoubtedly showed significant improvements in social functioning, there were still obvious impairments within this population. Second, and very importantly, the differences between the cognitive therapy group and the control group were only apparent during the active phase of treatment — the control group continued to make modest gains during the follow-up period so that at 1 year after cognitive therapy there was no difference in social functioning between the two groups. One conclusion from this result is that individuals who receive 16 sessions of cognitive therapy for chronic or residual depressive symptoms may benefit from additional but less-frequent maintenance cognitive therapy sessions.

Lastly, Ito et al are right to point out that calculations of numbers needed to treat from this study are indeed indicative of substantial benefits from using cognitive therapy. For the record, using data from our study and other recent studies, only four to six additional patients need be treated with cognitive therapy to prevent one relapse.