Treatment Algorithm for OCD


The guidelines below are intended to provide a series of treatment steps for OCD to clinicians. They are framed within recognisable tiers of service (primary care, secondary care, specialist/ tertiary care) and all treatments are evidence-based. Although each tier is included, it is expected that the suggested steps might be most useful for psychiatrists in secondary care/ CMHTs.


All prescribers need to be responsible for their own prescribing and there will always be factors that mean a specific treatment is not suitable. Many patients may have already had trials of particular drugs, and so strict adherence to an algorithm is rarely sensible.

General principles

These treatment guidelines are informed by several principles:

  1. The guidelines need to be simple, so all the underlying evidence is not included. Neither is lots of discussion about switchovers and side-effects. We expect clinicians to be able to inform patients appropriately and prescribe safely.
  2. Where there is uncertainty about which treatment is preferred, the patient should make this choice.
  3. Each step has a number of choices, most of which have similar risk/ benefit ratios.

Clinicians are, of course, not obliged to follow these before making a referral to the Advanced Interventions Service but the principles of how many treatments are likely to have been delivered within each tier of service delivery are often a factor when considering referrals and making treatment recommendations.



Download this algorithm as a PDF (170Kb) | Last updated: 19 October 2021