Although selective serotonin reuptake inhibitors (SSRIs) are an effective treatment option for patients with OCD, research at the time showed that patients experienced a 40-60% reduction in symptoms. 30-40% of individuals with OCD did not respond at all.
This study by Dr. Rosenberg and his team investigated the neurobiology behind SSRI-resistant OCD, specifically the functions of serotonin (a neurotransmitter responsible for mood, cognition, reward, and memory) and norepinephrine (a neurotransmitter and hormone responsible for arousal, alertness, and responding to stress and danger). Prior research at the time found that combining SSRIs with clomipramine (a tricyclic antidepressant) can lead to marked improvement for children and teenagers, and that using lower doses of both could lead to less side effects. Other studies showed that adding risperidone (an antipsychotic) to SSRIs can reduce OCD symptom severity, especially when patients also had a tic disorder. The double-blind randomized study consisted of giving children with OCD (8-18 years old) an SSRI for 12 weeks, after which non-responders would also take either clomipramine or risperidone with an SSRI for 8 more weeks. Its goals were to test the efficacy of this approach and to understand what the lowest dosages would be to achieve efficacy.