Efficacy of D-Cycloserine in combination with intensive exposure therapy in the treatment of obsessive compulsive disorder (OCD) in children

INTERVENTION: D‐cycloserine (DCS) augmented intensive exposure therapy versus pill placebo and intensive exposure therapy. Participants receive four individual intensive exposure therapy sessions. All intensive sessions will be 3 hours in duration. The first three intensive sessions will be spaced one week apart. The final booster intensive session will be one month after the third intensive session. The sessions involve assisting participants to systematically and gradually face their fears whilst resisting any ritualising. There will be two conditions. Half of participants will be given DCS immediately prior to starting their intensive cognitive‐behavioural therapy treatment sessions and half will be given a placebo pill immediately prior to starting their intensive cognitive‐behavioural therapy treatment sessions. Participants will remain in the same dosing conditions across all treatment sessions. Particiapants will therefore have four doses of DCS or Placebo during the trial. The DCS dosage will be 35mg or 70mg depending on the child's weight. Children weighing 25kg to 45kg will receive 35mg DCS which equals a range of 1.4mg/kg to 0.78 mg/kg and children 46kg to 90kg, will be given a dose of 70mg, which equates to a range of 1.5mg/kg to 0.78mg/kg. Each dose is given orally in a capsule and supervised administration occurs by the therapy psychologist. The exposure therapy is delivered via trained psychologists. CONDITION: Pediatric Obsessive Compulsive Disorder PRIMARY OUTCOME: CYBOCS Total OCD severity NIMH CGI Severity ‐ Clinical Global Severity / Improvements Obsessive Compulsive Diagnostic Severity (ADIS‐P, CSR) SECONDARY OUTCOME: Anxiety ‐ Multidimensional Anxiety Scale for Children (child report) Depression ‐ Children's Depression Inventory Target symptoms ‐ top three symptoms child and parent reported and ratings of severity using 9‐point Likert scale response (How severe has this symptom been in the past week) functional impairment ‐ Child OCD Impact Scale (child and parent version) INCLUSION CRITERIA: Inclusion criteria ‐ (a) primary diagnosis of OCD with score of at least 16 on CYBOCS at pre‐ (moderate range) (b) aged 7‐17 years (c) at least one parent willing to attend (d) suspected IQ within at least average range and ability to understand cognitive components of treatment ‐ IQ will not be formally assessed in this project. Rather, this will be based on parent report of children’s general intellectual functioning during intake screening, and will involve asking the parent if they consider their child’s intellectual functioning to be at least in the low average range for children his/her age and they could understand general cognitive components of treatment. (e) willingness to cease any other concurrent psychotherapy related to OCD treatment (f) If taking psychotropic medication the following stabilization periods need to be completed prior to study entry *If SSRI stable for 12 weeks prior to entering the study * 6