Blog post. Most people who undertake psychotherapy seem to benefit from it. How do we know? Arguably, the most important evidence comes from meta-analyses that combine the results from many – sometimes hundreds – of randomly controlled trials. Based on this, it’s been estimated that psychotherapy is effective for about 80 per cent of people (meanwhile, between five to 10 per cent of clients may suffer adverse effects).

But now the more concerning news: a team of researchers led by Evangelos Evangelou at the University of Ioannina, Greece has assessed the quality of 247 of these psychotherapy meta-analyses and they report in Acta Psychiatrica Scandinavica that many of them have serious methodological short-comings.