The purpose of this research study is to further investigate how well cognitive-behavioral psychotherapy works to reduce obsessive-compulsive symptoms in young children with obsessive-compulsive disorder (OCD). Cognitive-behavioral therapy has been shown to work well in youth with OCD and other anxiety disorders; however, there are only a few studies to date in preschool and young children with OCD. All children will have the option to receive 12 twice-weekly cognitive-behavioral psychotherapy sessions that are up to 60-minutes each. Randomly determined, half of all children will receive these sessions immediately following the pre-assessment and the remaining half will receive them after six weeks. The investigators expect that youth receiving the study-based therapy will show more improvement in OCD symptoms in six weeks in contrast to youth waiting to receive the therapy.

Cognitive Behavioral Therapy for OCD includes several core therapeutic elements including establishment of treatment goals, assigned homework, operant conditioning paradigms (the putative mechanism for exposure-based therapies), provision of psychoeducation (e.g., the link between thoughts, feelings, and behaviors), cognitive (e.g., cognitive restructuring) and behavioral (e.g., exposure) coping skill implementation, and target behavior progress assessments. Nevertheless, research is lacking in preschoolers with OCD and these children likely require adaptations to the traditional CBT regimen. Preschoolers often have a high level of family accommodation, whereby the family members become part of the rituals and compulsions in attempt to ease the young child's anxiety. CBT with preschoolers will need to emphasize delivering intervention within the context of the family. The flexibility of this modular approach for treatment (modular therapies allow for variations in the order and intensiveness of the aforementioned treatment elements, providing an individually tailored treatment instead of a one-size-fits-all approach) may be optimally suited for preschoolers with OCD given their wide variability in developmental level and symptom presentation. This is consistent with the NIH Roadmap Initiative which calls for personalized interventions matched to individual patient characteristics. Our OCD research team in the Rothman Center is highly experienced in clinical research for pediatric and adult OCD. The proposed investigation is a single-site controlled trial of CBT in preschool aged youth with OCD aged 3-8 years. We will randomly assign patients to immediate treatment or 6-week Treatment as Usual (TAU) control. A manualized CBT protocol will be followed. Assessments will occur at Screening, Baseline, Post-treatment and 1 and 3-month follow-ups. Ratings of patient OCD symptom severity will be conducted at each time point by trained raters blinded to treatment condition. Diagnosis will be established by an experienced clinician and verified by a validated rating scale conducted with the child's parent(s); cases will be reviewed by study investigators. Assessments will be audio-recorded and verified for integrity. Randomization will be determined immediately following the baseline assessment; patients will be assigned TAU or immediate treatment in a 1:1 ratio. All eligible patients will receive 12 therapy sessions over 6 weeks using the evidence-based treatment protocol that incorporates E/RP and parent involvement; sessions are twice weekly for 60 minutes. Dr. Lewin and other trained OCD therapists under his supervision will conduct therapy sessions. All sessions are audiorecorded for integrity.

Inclusion Criteria:

• Meets DSM-IV-TR for a primary diagnosis of OCD
• Minimum score of 8 on the CYBOCS compulsion scale
• Peabody Picture Vocabulary IV score of 80
• Able to attend biweekly appointments with a parent/guardian
• English Speaking

Exclusion Criteria:

• Current clinically significant suicidality
• engaged in suicidal behaviors within 6 months
• Peabody Picture Vocabulary IV score of 80
• Any change in established psychotropic medication (e.g., antidepressants, anxiolytics) within 4 weeks before study enrollment, any change in antipsychotics within 3 weeks prior to the screening assessment, any change in Prozac or Straterra within 6 weeks of study enrollment, and any change in alpha-2 agonists or stimulants within 1 week of study enrollment.
• Lifetime DSM-IV bipolar, schizophrenia or schizoaffective disorders; or Substance abuse in past 6 months.
• Absence of language
• Formal diagnosis of mental retardation or an autism spectrum disorder
• Unwillingness of parents to make the commitment to accompany their child for multiple study visits, unwillingness to take part in randomization, inability to attend sessions twice weekly as therapist availability allows, inability to attend assessment visits.
• Presence of a significant and/or unstable medical illness which might lead to hospitalization during the study.