D-cycloserine may have insignificant benefits to OCD, AD
D-cycloserine (DCS), used to augment behaviour therapy in patients with obsessive-compulsive (OCD) and anxiety disorders (AD), may have very little to almost no effect, a new meta-analysis reveals.
Web of Science, PubMed, PsychArticles, Psyndex and PsycInfo were accessed for this meta-analysis. Only randomized, placebo-controlled, double-blinded studies that examined the effect of DCS interventions on cognitive behavioural therapy (CBT) on human patients with anxiety and obsessive-compulsive disorders were included.
The methodological qualities and risk of bias of the studies selected were evaluated using a self-developed scale based on the method of the Cochrane Collaboration.
The search resulted in 23 studies corresponding to a cumulative sample size of 1,314 patients (659 received DCS, 655 were controls). The mean quality score of the studies was 8.4 (range, 6.5 to 10).
The Hedge’s g estimates, which do not take into account pretreatment values, showed that DCS had no effect on CBT for mid-treatment (g, -0.12; 95 percent CI, -0.28 to 0.07; p=0.14) and only a small effect post-treatment (g, -0.12; -0.47 to -0.08; p<0.01).
On the other hand, the standardized mean change score (SMCC), which controls for the pretreatment values, showed that DCS had no significant effect during mid-treatment (SMCC, -0.05; -0.26 to 0.15; p=0.31), post-treatment (SMCC, -0.10; -0.29 to 0.07; p=0.13) and a 1-month follow-up (SMCC, -0.18; -0.46 to 0.10; p=0.10).
Despite previous meta-analyses finding DCS to yield moderate improvements, the most recent studies indicate that this may actually be insignificant. Primary studies of higher quality are needed to avoid overestimation of the benefits and effects of such interventions.