Integrating Exposure and Response Prevention and Habit Reversal Techniques to Treat a Tourettic Subtype of Obsessive-Compulsive Disorder (Tourettic OCD)

Obsessive-Compulsive Disorder and Tic Disorders frequently co-occur, and a subgroup of patients - those with a Tourettic Subtype of OCD (TOCD) - present with concurrent obsessive-compulsive and tic symptoms. Existing psychological interventions typically target one condition or the other, but rarely both together. This study aims to test whether a combined psychological therapy integrating Exposure and Response Prevention (ERP) and Habit Reversal (HbRT) is more effective at reducing symptoms than either therapy delivered alone, in adults with TOCD.

Inclusion Criteria: 1. Age 18 years or older 2. All genders 3. Confirmation of a primary diagnosis of either: a. Tourettes Disorder / Tourette Syndrome b. Persistent Motor or Vocal Tic Disorder / Chronic Motor or Vocal Tic Disorder c. Provisional Tic Disorder / Transient Motor Tics d. Other Specified Tic Disorder e. Unspecified Tic Disorder f. Obsessive-Compulsive Disorder \[d\] Participants taking psychotropic medication are eligible provided medication type and dose remain stable throughout the intervention period \[e\] Ability to provide sustained informed consent \[f\] A minimum score of 16 on YBOCS \[g\] A minimum score of 5 on the Premonitory Urge for Tics Scale (PUTS) Exclusion Criteria: 1. Substance misuse 2. Current diagnosis of a personality disorder 3. Schizophrenia 4. Bipolar disorder 5. Contraindications to participation in a trial (i.e., active suicidal ideations and/or requirement of an interpreter) 6. Any psychiatric or neurological condition that, in the opinion of the investigators, would interfere with participation or interpretation of study outcomes.