Summary points

Please note that parts of this guideline may be out of date, an update will be published as soon as it is available.

• CBT and the serotonin re uptake inhibitors (SRIs), clomipramine and the SSRIs, are efficacious and safe first-line treatments for OCD.
• Whether to commence CBT or an SRI will depend on the nature and severity of symptoms, presence of co-occurring psychiatric and medical comorbidities and their treatments, a patient’s access to CBT, past treatment history, and patient preference.
• CBT alone, consisting of exposure and response prevention, is recommended as first-line for a patient who is not too depressed, anxious, or severely ill to co-operate with this treatment modality, or who prefers not to take medications and is willing to engage with CBT.
• SRI first-line treatment is recommended for a patient who has previously responded well to an SSRI or other drug, prefers medication treatment, or is not suited for CBT.
• Most patients will not experience substantial improvement until 4 - 6 weeks after initiating medication, and some patients who ultimately respond will experience little improvement by 8 - 10 weeks.
• Although some patients with OCD respond to standard doses of SRIs, others require doses that are much higher than those used for depression. In adults, clomipramine should be increased to approximately 250mg, and the SSRIs should be increased to maximal safe dosages (e.g. 60 - 80 mg of fluoxetine).
• At least a year of maintenance pharmacotherapy is reasonable in patients who respond to medication.
• CBT (exposure and response prevention) can be used alone or in combination with medication. Psycho-education is also crucial.
• When there is a partial response to an optimal trial of medication, or when there are comorbid tics, it may be useful to consider augmentation. Many OCD patients will have a meaningful treatment response to antipsychotic augmentation.