Forty-one studies were located, yielding 61 treatment outcome trials. Thirty-six trials were studies where two or more conditions were compared (parallel group design); 5 trials used cross-over designs; and in the remaining trials the design is not stated. Number of completers = 1029.
Psychological therapies had statistically significantly lower drop- out rates than pharmacotherapies (14% versus 32%), with attrition being uniformly low across all psychological therapies.
In symptom reduction, psychological therapies were more effective than drug therapies, and both were more effective than controls.
Among the drug therapies, SSRIs and carbamazepine had the greatest effect sizes, although the latter was based upon a single trial.
Among the psychological therapies, behaviour therapy and EMDR were most effective, and generally equally so.
The most effective psychological therapies and drug therapies were generally equally effective.
Differences across treatment conditions were generally evident across symptom domains, with little matching of symptom domain to treatment type. However, SSRIs had some advantage over psychological therapies in treating depression.
Follow-up results were not available for most treatments, but available data indicates that treatment effects for behaviour therapy and EMDR are maintained at 15-week follow-up.
For intrusions, drugs effect size was 0.86 (90% CI: 0.63,1.09) for self-report and 1.01 (90% CI: 0.71, 1.31) for observer-rated. Psychological interventions effect size was 1.02 (90% CI: 0.80,1.24) for self-report and 1.57 (90% CI: 1.12, 2.02) for observer-rated. For controls the effect size was 0.49 (90% CI: 0.29, 0.69) for self- report and 0.66 (90% CI: 0.54, 0.78) for observer-rated.
For avoidance, drugs effect size was 0.45 (90% CI: 0.31,0.59) for self-report and 1.00 (90% CI: 0.64, 1.36) for observer-rated. Psychological interventions effect size was 1.03 (90% CI: 0.77, 1.29) for self-report and 1.74 (90% CI: 1.23, 2.25) for observer-rated. For controls the effect size was 0.23 (90% CI: 0.06, 0.46) for self- report and 0.17 (90% CI: -0.18, 0.52) for observer-rated.
For total severity of PTSD symptoms, drugs effect size was 0.69 (90% CI: 0.55, 0.83) for self-report and 1.05 (90% CI: 0.91, 1.19) for observer-rated. Psychological interventions effect size was 1.17 (90% CI: 0.99, 1.35) for self-report and 1.51 (90% CI: 1.17, 1.85) for observer-rated. For controls the effect size was 0.43 (90% CI: 0.33, 0.53) for self-report and 0.77 (90% CI: 0.71, 0.83) for observer-rated.
For anxiety, drugs effect size was 0.61 (90% CI: 0.39,0.83) for self- report and 0.64 (90% CI: 0.61, 1.09) for observer-rated. Psychological interventions effect size was 1.04 (90% CI: 0.89, 1.19) for self-report and not reported for observer-rated. For controls the effect size was 0.17 (90% CI: 0.06, 0.28) for self-report and not reported for observer-rated.
For depression, drugs effect size was 0.65 (90% CI: 0.39,0.91) for self-report and 0.72 (90% CI: 0.55, 0.89) for observer-rated. Psychological interventions effect size was 1.00 (90% CI: 0.87, 1.13) for self-report and not reported for observer-rated. For controls the effect size was 0.23 (90% CI: 0.16, 0.30) for self-report and 0.36 (90% CI: 0.19, 0.53) for observer-rated.
Effect sizes at follow up (15 weeks) were:
1. For intrusions self-report M = 1.56 (90% CI: 0.81, 2.29) for behavioural interventions and M = 1.75 (90% CI: 1.46, 2.04) for EMDR.
2. For intrusions observer-rated M = 1.47 (90% CI: 0.60, 2.34) for behavioural interventions and M = 2.07 (90% CI: 1.77, 2.37) for EMDR.
3. For avoidance self-report M = 1.44 (90% CI: 0.47, 2.41) for behavioural interventions and M = 1.89 (90% CI: 1.08, 2.70) for EMDR.
4. For avoidance observer-rated M = 1.32 (90% CI: 0.71, 1.93) for behavioural interventions and M = 2.34 (90% CI: 1.76, 2.92) for EMDR.
5. For total severity of PTSD symptoms self-report M = 1.63 (90% CI: 1.10, 2.16) for behavioural interventions and M = 1.33 (90% CI: 0.89, 1.77) for EMDR.
6. For total severity of PTSD symptoms observer-rated M = 1.93 (90% CI: 1.67, 2.19) for behavioural interventions and M = 2.27 (90% CI: 1.78, 2.76) for EMDR.
7. For anxiety self-report M = 0.99 (90% CI: 0.66, 1.32) for behavioural interventions and M = 0.90 (90% CI: 0.64, 1.16) for EMDR (with no data on anxiety observer-rated reported).
8. For depression self-report M = 0.93 (90% CI: 0.76, 1.10) for behavioural interventions and M = 0.91 (90% CI: 0.46, 1.36) for EMDR (with no data on depression observer-rated reported).