Evidence category
Psychotherapy comparators, allegiance effects, and the dodo bird verdict.
Waitlist controls inflate psychotherapy effect sizes by 50%: depression versus waitlist g=0.95, versus care-as-usual g=0.63. Response rates are modest: 24-42% across disorders. Head-to-head trials show medication 46.4%, psychotherapy 46.3%, mixed controls 24.4% remission. Common factors account for large variance. Treatment differences exist for some disorders, not others. Neither 'huge effects' nor 'just talking to a friend' survives.