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D-Cycloserine Enhancement of Exposure in Social Phobia

D-Cycloserine Enhancement of Exposure in Social Phobia

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00633984
Enrollment
169
Registered
2008-03-12
Start date
2007-03-31
Completion date
2012-09-30
Last updated
2014-05-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Social Anxiety Disorder

Keywords

Social Anxiety Disorder, Cognitive Behavioral Group Therapy, D-cycloserine

Brief summary

The purpose of this study is to test a drug called d-cycloserine to see if it can help people with a condition called social phobia. Social phobia is also called social anxiety disorder. Social phobia is a constant fear of social or performance situations. Social situations include group gatherings of any kind. Performance situations might include times when a person would have to do something in public, such as speak up in class or at a meeting. A person with this condition worries about being embarrassed, or about other people's opinions. People with social phobia usually feel extremely anxious (nervous and worried) about being the focus of attention. They often avoid social and performance situations. This behavior can have a negative effect on the quality of their lives and relationships. In this study, we want to find out if d-cycloserine can help control social phobia when the drug is added to the standard treatment for this condition. The standard treatment is cognitive-behavior therapy (CBT). CBT is a form of talk therapy involving discussion with a therapist, along with practicing the feelings or events that the person finds frightening.

Detailed description

Inclusion criteria: 1. Age 18 or older 2. Primary diagnosis of SAD 3. Physical examination, electrocardiogram, and laboratory findings without clinically significant abnormalities. 4. Willingness and ability to comply with the requirements of the study protocol. Diagnostic 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 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 within the past 6 months are excluded. Entry of patients with other mood or anxiety disorders will be permitted if the social anxiety disorder is judged to be the predominant disorder, 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 the GSAD is excluded. Prohibited psychotherapy includes CBT or psychodynamic 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.

Interventions

The patient will then receive 12 weekly sessions of Cognitive Behavioral Therapy lasting approximately two and a half hours each. During these sessions, patients will receive information on the nature of social phobia and a model of treatment and will receive weekly training in how to become more comfortable with social situations, with the goal of achieving confidence in social interactions. As part of this training, the therapist will practice social interactions with the patient, who will also be asked to practice what they have learned outside of the therapists' office.

DRUGD-Cycloserine

For the third, fourth, fifth, sixth, and seventh sessions of the twelve-session program of Cognitive Behavioral Therapy, the patient will be asked to arrive one hour early to take one of the study pill, a 50mg pill of d-cycloserine. A physician will be available in the unlikely event that a patient begins to experience side effects. Before the treatment starts, before the eighth session, and one week after the final session patients will have a separate visit in which their levels of symptoms assessed with measures of mood, anxiety, and avoidance.

DRUGPlacebo

For the third, fourth, fifth, sixth, and seventh sessions of the twelve-session program of Cognitive Behavioral Therapy, the patient will be asked to arrive one hour early to take one of the study pill, a placebo. A physician will be available in the unlikely event that a patient begins to experience side effects. Before the treatment starts, before the eighth session, and one week after the final session patients will have a separate visit in which their levels of symptoms assessed with measures of mood, anxiety, and avoidance.

Sponsors

Boston University
CollaboratorOTHER
Southern Methodist University
CollaboratorOTHER
National Institutes of Health (NIH)
CollaboratorNIH
National Institute of Mental Health (NIMH)
CollaboratorNIH
Massachusetts General Hospital
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Male or female outpatients \> 18 years of age with a primary psychiatric diagnosis (designated by the patient as the most important source of current distress) of generalized social anxiety disorder (GSAD) as defined by DSM-IV criteria. 2. A total score \> 60 on the LSAS. 3. Physical examination, electrocardiogram, and laboratory findings without clinically significant abnormalities. 4. 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 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 within the past 6 months are excluded. Entry of patients with other mood or anxiety disorders will be permitted if the social anxiety disorder is judged to be the predominant disorder, 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 the GSAD is excluded. Prohibited psychotherapy includes CBT or psychodynamic 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.

Design outcomes

Primary

MeasureTime frameDescription
Liebowitz Social Anxiety Scale (LSAS)Week 13The Liebowitz Social Anxiety Scale (LSAS) is a 24-item measure designed to assess both fear and avoidance of social and performance situations occurring in the last week. Each item is rated from 0-3 for both fear and avoidance with a possible score of 144; 55-65 Moderate social phobia, 65-80 Marked social phobia, 80-95 Severe social phobia, and Greater than 95 - Very severe social phobia. Remission was defined as a score of \< 30 on the Liebowitz Social Anxiety Scale
CGI - Clinical Global Impression of ImprovementWeek 13The Clinician Global Impression-Improvement Scale (CGI-I) is a clinician-rated instrument used to assess global severity of symptoms. The CGI-I ranges from 1 (very much improved) to 7 (very much worse). Response and remission was defined as an improvement score of 1 (very much improved) or 2 (much improved) on the CGI-I.

Countries

United States

Participant flow

Participants by arm

ArmCount
Cognitive Behavioral Group Therapy + 50mg D-Cycloserine
Participants received Cognitive Behavioral Group Therapy and 50mg D-Cycloserine.
87
Cognitive Behavioral Group Therapy + 50mg Placebo
Participants received Cognitive Behavioral Group Therapy and 50mg Placebo.
82
Total169

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyHospitalized10
Overall StudyLost to Follow-up06
Overall StudyWithdrawal by Subject87

Baseline characteristics

CharacteristicCognitive Behavioral Group Therapy + 50mg D-CycloserineCognitive Behavioral Group Therapy + 50mg PlaceboTotal
Age, Continuous34.6 years
STANDARD_DEVIATION 10.5
30.5 years
STANDARD_DEVIATION 9.8
32.6 years
STANDARD_DEVIATION 10.4
Region of Enrollment
United States
87 participants82 participants169 participants
Sex: Female, Male
Female
31 Participants42 Participants73 Participants
Sex: Female, Male
Male
56 Participants40 Participants96 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
— / —— / —
other
Total, other adverse events
26 / 8719 / 82
serious
Total, serious adverse events
0 / 870 / 82

Outcome results

Primary

CGI - Clinical Global Impression of Improvement

The Clinician Global Impression-Improvement Scale (CGI-I) is a clinician-rated instrument used to assess global severity of symptoms. The CGI-I ranges from 1 (very much improved) to 7 (very much worse). Response and remission was defined as an improvement score of 1 (very much improved) or 2 (much improved) on the CGI-I.

Time frame: Week 13

ArmMeasureValue (MEAN)
Cognitive Behavioral Group Therapy + 50mg D-CycloserineCGI - Clinical Global Impression of Improvement2.68 units on a scale
Cognitive Behavioral Group Therapy + 50mg PlaceboCGI - Clinical Global Impression of Improvement2.95 units on a scale
Primary

Liebowitz Social Anxiety Scale (LSAS)

The Liebowitz Social Anxiety Scale (LSAS) is a 24-item measure designed to assess both fear and avoidance of social and performance situations occurring in the last week. Each item is rated from 0-3 for both fear and avoidance with a possible score of 144; 55-65 Moderate social phobia, 65-80 Marked social phobia, 80-95 Severe social phobia, and Greater than 95 - Very severe social phobia. Remission was defined as a score of \< 30 on the Liebowitz Social Anxiety Scale

Time frame: Week 13

ArmMeasureValue (MEAN)
Cognitive Behavioral Group Therapy + 50mg D-CycloserineLiebowitz Social Anxiety Scale (LSAS)39.19 units on a scale
Cognitive Behavioral Group Therapy + 50mg PlaceboLiebowitz Social Anxiety Scale (LSAS)42.44 units on a scale

Source: ClinicalTrials.gov · Data processed: Mar 23, 2026