A pilot study of D-cycloserine-augmented cognitive behavioural therapy (CBT) with exposure therapy in adolescents with obsessive-compulsive disorder (OCD)

Children's Yale Brown Obsessive Compulsive Scale (CYBOCS), a well-validated clinician administered measure of OCD severity. For each arm, this measure will be administered at the beginning of each session, and again at 3 months, 6 months and 12 months post-treatment.

1. Diagnosis of OCD as determined with:
1.1. The Anxiety Disorders Interview Schedule for DSM-IV (ADIS), the Child Obsessive-Compulsive Inventory (ChOCI), child and parent versions
1.2. The Strengths and Difficulties Questionnaire (SDQ), child and parent versions
1.3. The Beck Depression Inventory for Youth (BDI-Y)
1.4. The Depression Anxiety and Stress Scale (DASS) for parents
1.5. The Family Accommodation Scale (FAS)
2. Additional ‘process’ variables include measures of trait anxiety (RCMAS), threat perception (CARBQ-C/P), subjective anxiety (SUDS ratings), behavioural avoidance tasks (BATs), physiological arousal (heart rate variability) and the Patient Exposure Adherence Scale (PEAS)
3. Behavioural Avoidance Task (BAT). A single task, single-step BAT will be administered. The task will be described to the child using standardised instructions. The BAT is an individually tailored task in which the young person is asked to expose him/herself to a situation that usually causes him/her significant distress or results in compulsive rituals.
4. Subjective units of distress (SUDS). Young people will be asked to rate their subjective distress at various time points during the BAT task, based on an 8-point Likert scale thermometer (0 = none to 8 = extreme).
5. Heart Rate Variability (HRV). HRV is a measure of the beat-to-beat variations in heart rate. It is calculated by analysing a time series of beat-to-beat intervals from a heart rate monitor. HRV is an indicator of autonomic arousal, and there is a known relationship between HRV and emotional arousal. HRV has been shown to be sensitive to the emotion of fear in most people. Therefore HRV will be used as a measure of physiological arousal in relation to the BAT task. HRV will be measured using a Polar heart rate monitor (FT80). A heart rate monitor consists of two elements: a chest strap transmitter and a wrist receiver (a sports watch). The chest strap has electrodes in contact with the skin to monitor electrical voltages in the heart.
6. Cognitive and Avoidant Response Bias Questionnaire - Child and Parent Versions (CARBQ-C/P). Threat perception and coping expectations in response to both generic, non-salient situations as well as to personally salient situations (i.e. situations that the young person perceives to be anxiety provoking) will be measured using the Cognitive and Avoidant Response Bias Questionnaire (CARBQ). It is also of interest to examine parents (mothers) levels of threat perception and coping expectations for their child.

Secondary outcome measures will be completed at 3 months, 6 months and 12 months post-treatment.