(PS7-D79) Simultaneous Combination of Pharmacotherapy and CBT for OCD

It is well established that pharmacotherapy and cognitive-behavioral therapy (CBT) are effective monotherapies for obsessive-compulsive disorder (OCD).  The present meta-analysis examined the impact of combined CBT and pharmacotherapy compared to monotherapy. We conducted a search on PubMed and PsychInfo. Criteria for inclusion were randomized controlled trials for OCD patients (adults or children) that included a CBT + SRI (SSRI or clomipramine) condition and one of the following: (a) an SRI monotherapy condition or an SRI + inert psychological treatment condition, or (b) a CBT monotherapy or CBT + pill placebo (PBO) condition. The search revealed 14 studies meeting inclusion criteria. Studies showed wide variability in improvement for CBT monotherapy ranging from 18%-76% reductions in OCD symptom severity (M = 42%). Medication monotherapy showed less variability, with OCD symptom reduction ranging from 22% - 47% (M = 33%). When combination therapy was provided, symptom reduction ranged from 35%-81% (M = 53%). The sampled studies also indicated that CBT monotherapy, medication monotherapy, and combined therapy showed continued symptom reduction through follow up (31%, 39%, and 54%, respectively). Random-effects model meta-analytic strategies were employed using Comprehensive Meta-Analysis to examine treatment effect sizes across studies. One study did not provide the necessary outcomes and was therefore excluded from the meta-analysis. This process resulted in 19 comparisons from 13 studies with a total of 1010 participants that met inclusion criteria. Combined CBT and medication was associated with lower symptom severity at post-treatment than was medication monotherapy [k (number of samples) = 10, Hedges’ g = 1.185 (0.409-1.961), p = .003. This finding was robust against the file drawer effect (Fail Safe N [FSN] = 335).  Combined CBT and medication was associated with a small but significant effect showing lower post-treatment severity compared to CBT monotherapy [k = 9, g = 0.253 (0.031-0.475), p = 0.026, but this effect was not robust against the file drawer effect (FSN = 2). Results of this meta-analysis indicate that CBT and medication is superior to medication monotherapy, whereas the superiority of CBT and medication over CBT monotherapy is small and not robust.  These impressions must be considered tentative for several reasons.  The number of studies is relatively small, though the finding of combined therapy’s advantage over medication monotherapy is robust against the file drawer effect. Further, there was variability in CBT treatment administration and long-term follow up outcomes require further assessment over time and over longer follow up intervals.