Are Treatment Effects Maintained Over Time?
Twelve studies with PTSD populations assessed treatment maintenance by analyzing differences in outcome between post-treatment and follow-up. Follow-up times have varied and include periods of 3, 4, 9, 15 months, and 5 years after treatment. Treatment effects were maintained in eight of the nine studies with civilian participants; one study (Devilly & Spence, 1999) reported a trend for deterioration. Of the three studies with combat veteran participants only one (Carlson et al., 1998) provided a full course of treatment (12 sessions). This study found that treatment effects were maintained at 9 months. The other two studies provided limited treatment: Devilly, Spence and Rapee (1998) provided two sessions and moderate effects at post-test were not maintained at follow-up. Pitman et al. (1996) treated only two of multiple traumatic memories, and treatment effects were not maintained at 5 year follow-up (Macklin et al., 2000). It appears that the provision of limited treatment may be inadequate to fully treat the disorder, resulting in remission of the partial effects originally achieved.