Delayed- Maturation Theory of Obsessive Compulsive Disorder
Drug treatment of OCD may be assumed to affect a proposed functional imbalance between the frontal lobes and other parts of the brain. Serotonin reuptake inhibitors, SRI, especially potent ones given at high doses over long periods of time, are often effective in the treatment of obsessive-compulsive disorder. However, a large percentage of patients do not respond to treatment with the SRI, and those who do respond often do not fully remit, which should be the standard goal of treatment in OCD. If a patient has been treated for several months and has not yet responded to treatment with several types of SRI medication, the physician should perform a careful assessment of resistant and/or residual clinical symptoms. Any comorbid conditions to determine which next-step treatment would be the most appropriate. One strategy for patients who have not responded to treatment with a SRI is to switch them to aserotonin-norepinephrine reuptake inhibitors.
Clomipramine
Clomipramine was the first drug that was investigated for and found to be effective in the treatment of OCD. In addition, it was the first drug to be approved by the in the United States for the treatment of OCD. The effectiveness of clomipramine in the treatment of OCD is far greater than that of other TCAs, which are comparatively weak SRIs; a meta-analysis found pre- versus post-treatment effect sizes of 1.55 for clomipramine relative to a range of 0.67 for imipramine and 0.11 for desipramine. In contrast to other TCAs, studies have found that clomipramine and SSRIs, which are more potent SRIs, have similar effectiveness in the treatment of OCD. However, multiple meta-analyses have found that clomipramine nonetheless retains a significant effectiveness advantage relative to SSRIs; in the same meta-analysis mentioned previously, the effect sizes of SSRIs in the treatment of OCD ranged from 0.81 for fluoxetine to 1.36 for sertraline (relative to 1.55 for clomipramine). However, the effectiveness advantage for clomipramine has not been apparent in head-to-head comparisons of clomipramine versus SSRIs for OCD. The differences in effectiveness findings could be due to differences in methodologies across non-head-to-head studies.