Overall 48 primary studies were included (> 2000 patients).
Methodological problems in the primary studies included: small sample size; short-term or no follow-up; high attrition at follow-up; no control or comparison group; and the use of retrospective measures. Only results from studies meeting the APA criteria for empirically-validated psychological treatments are reported below as stated by the authors. Outcomes from individual studies were reported in tables of study characteristics with no point estimates, confidence intervals or levels of significance making interpretation difficult.
Stimulus control therapy (4 studies): all demonstrated improved sleep for treatment compared to placebo controls or other single interventions (progressive muscle relaxation, imagery training).
Sleep restriction (1 study): improved sleep compared to placebo.
EMG Biofeedback (4 studies): all showed this to be a more effective treatment for insomnia than no treatment, waiting list control or placebo.
Paradoxical intention (2 studies): both reported greater benefit compared to placebo.
Multicomponent cognitive behavior therapy (2 studies published by same author in same year): both reported greater benefit compared to waiting list control or placebo.