D-Cycloserine to Enhance Cognitive Behavioral Therapy (CBT) for Acrophobia
Condition: Phobic Disorders
MeSH terms: Phobic Disorders
Intervention: Individual Cognitive Behavioral Therapy (CBT); D-Cycloserine; Placebo
Intervention description: The aim of CBT is to help participants become more comfortable with heights situations. Participants will receive 2 sessions over two weeks of individual CBT.; D-Cycloserine; Sugar Pill
Intervention MeSH terms: Cycloserine
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Enrollment: 40.0
Sex: All
Minimum age: 18 Years
Maximum age: 65 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Phobias; Anxiety Disorders; D-Cycloserine; Phobic Disorders; Mental Disorders; Heights; Acrophobia

Summary:

      The purpose of this study is to investigate the utility of post-session administration of
      D-cycloserine to enhance fear extinction in a sample of people with acrophobia who will be
      treated with CBT.
    

Eligibility criteria:

        Inclusion Criteria:

          1. Males or females 18-65 years of age with a psychiatric diagnosis of acrophobia defined
             by DSM-IV criteria.

          2. Willingness and ability to comply with the requirements of the study protocol.

        Exclusion Criteria:

          1. A lifetime history of bipolar disorder, schizophrenia, psychosis, delusional disorders
             or obsessive-compulsive disorder; an eating disorder in the past 6 months; organic
             brain syndrome, mental retardation or other cognitive dysfunction that could interfere
             with capacity to engage in therapy; a history of substance (amphetamines,
             benzodiazepines, barbiturates, cocaine metabolites, marijuana, narcotics, and sedative
             hypnotics) abuse or dependence or alcohol abuse or dependence (other than nicotine) in
             the last 6 months or otherwise unable to commit to refraining from alcohol use during
             the acute period of study participation.

          2. Patients with posttraumatic stress disorder and panic disorder within the past 6
             months are excluded. Entry of patients with other mood or anxiety disorders will be
             permitted in order to increase accrual of a clinically relevant sample. Patients with
             significant suicidal ideation (MADRS item 10 score > 3) or who have enacted suicidal
             behaviors within 6 months prior to intake will be excluded from study participation
             and referred for appropriate clinical intervention.

          3. Patients must be off concurrent psychotropic medication (e.g., antidepressants,
             anxiolytics, beta blockers) for at least 2 weeks prior to initiation of randomized
             treatment.

          4. Significant personality dysfunction likely to interfere with study participation.

          5. Serious medical illness or instability for which hospitalization may be likely within
             the next year.

          6. Patients with a current or past history of seizures.

          7. Pregnant women, lactating women, and women of childbearing potential who are not using
             medically accepted forms of contraception (e.g., IUD, oral contraceptives, barrier
             devices, condoms and foam, or implanted progesterone rods stabilized for at least 3
             months).

          8. Any concurrent psychotherapy initiated within 3 months of baseline, or ongoing
             psychotherapy of any duration directed specifically toward treatment of acrophobia is
             excluded. Prohibited psychotherapy includes CBT therapy focusing on exploring
             specific, dynamic causes of the phobic symptomatology and provides management skills.
             General supportive therapy initiated > 3 months prior is acceptable.

          9. Prior non-response to adequately delivered exposure (i.e., as defined by the patient's
             report of receiving specific and regular exposure assignments as part of a previous
             treatment) will exclude participants from the study.

         10. Patients with a history of head trauma causing loss of consciousness, seizure or
             ongoing cognitive impairment.

         11. Patients receiving isoniazid.

         12. Patients unable to understand study procedures and participate in the informed consent
             process.