Lancet, Early Online Publication, December 7, 2012 doi:10.1016/S0140-6736(12)61552-9
Also available online in the Lancet is the result of the CoBaLt trial which was a trial of cognitive behaviour therapy in people who had failed to respond to antidepressants in primary care in England. Failure to respond to antidepressants is the norm with only a third of people responding fully to antidepressants. The authors recruited 469 patients into the trial with 235 randomized to usual care and 234 to cognitive behaviour therapy plus usual care. To get into the trial participants had to have been on antidepressants for longer than six weeks, have a BDI score greater than 13, be aged 18-75 and meet ICD 10 criteria for depression.
Most people in the trial had received treatment for depression for over a year. One year after starting the trial 95 participants in the intervention group (46%) met criteria for response versus 46 (22%) in the usual care group. This means that about four people need to be treated with CBT for 12 to 18 sessions to get one extra person better after one year compared to usual care. One of the most noticeable aspects of this trial is that it demonstrated the acceptability of psychological treatments with 99% of patients invited for baseline assessment agreeing to participate. This is in contrast to the flawed STAR*D trial where only a quarter of participants were willing to be randomised to CBT.