The effect of psychological interventions on anxiety and depression in cancer patients: results of two meta analyses

The findings of two meta-analyses of trials of psychological interventions in patients with cancer are presented: the first using anxiety and the seco nd depression, as a main outcome measure. The majority of the trials were p reventative, selecting subjects on the basis of a cancer diagnosis rather t han on psychological criteria. For anxiety, 25 trials were identified and s ix were excluded because of missing data. The remaining 19 trials (includin g five unpublished) had a combined effect size of 0.42 standard deviations in favour of treatment against no-treatment controls (95% confidence interv al (CI) 0.08-0.74, total sample size 1023). A most robust estimate is 9.36 which is based on a subset of trials which were randomized, scored well on a rating of study quality, had a sample size >40 and in which the effect of trials with very large-effects were cancelled out. For depression; 30 tria ls were identified, but ten were excluded because of missing data. The rema ining 20 trials (including six unpublished) had a combined effect size of 0 .36 standard deviations in favour of treatment against no-treatment control s (95% CI 0.06-0.66, sample size 1101). This estimate was robust for public ation bias, but not study quality, and was inflated by three trials with ve ry large effects. A more robust estimate of mean effect is the clinically w eak to negligible value of 0.19. Group therapy is at least as effective as individual. Only four trials targeted interventions at those identified as- at risk of, or suffering significant psychological distress, these were ass ociated with clinically powerful effects (trend) relative to unscreened sub jects. The findings suggest that preventative psychological interventions i n cancer patients may have a moderate clinical effect upon anxiety but not depression. There are indications that interventions targeted at those at r isk of or suffering significant psychological distress have-strong clinical effects. Evidence an the effectiveness of such targeted interventions and of the feasibility and effects of group therapy in a European context is re quired.