Serotonergic antidepressants, such as selective serotonin reuptake inhibitors (SSRIs) and clomipramine, have long been used as first-line therapies for OCD. Medium to high doses and acute therapy for at least three months are advised until effectiveness is determined. If symptoms do not improve with antidepressant therapy, other options include cognitive behavioral therapy and electroconvulsive therapy. The use of antipsychotics in the treatment of obsessive-compulsive disorder (OCD) has increased in recent years. The most commonly used agents are olanzapine and risperidone. Although there is some evidence that these drugs can help reduce obsessive thoughts and compulsive behaviors, more research is needed before any major conclusions can be drawn about their effectiveness for this purpose. Cognitive behavior therapy (CBT) is considered the "first-line" treatment for OCD. It involves learning different strategies to replace obsessive thinking patterns with alternative ways of responding to situations that cause discomfort or anxiety. Therapy typically lasts for several months and is often combined with medication or other treatments such as exposure and response prevention (ERP). Results from clinical trials indicate that approximately 80% of people who receive CBT remain symptom free one year after completion of treatment. Electroconvulsive therapy (ECT) uses a small electric current to induce a seizure in order to relieve severe obsessions or compulsions that will not go away with counseling or medications.