Efficacy of Antidepressants in Chronic Back Pain

Study Overview
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Brief Summary
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This 12 week placebo controlled clinical trial tests the individual and combined effects of an antidepressant medication and cognitive behavioral therapy for chronic back pain.

Detailed Description
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This is a 4 arm 12 week randomized clinical trial comparing the efficacy of 1) low concentration desipramine (< 60 ng/ml); 2) cognitive behavioral therapy; 3) low concentration desipramine + cognitive behavioral therapy; and 4) placebo medication (benzotropine mesylate).

Official Title
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Efficacy of Antidepressants in Chronic Back Pain

Conditions
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Back Pain

Intervention / Treatment
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* Behavioral: cognitive behavioral therapy
* Drug: desipramine hydrochloride
* Behavioral: cognitive behavioral therapy
* Drug: benztropine mesylate 0.125 mg daily
* Drug: desipramine hydrochloride


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Chronic back pain (daily pain for > 6 months) Exclusion Criteria: Major medical conditions which might contraindicate antidepressant treatment

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Arm 1<br>desipramine hydrochloride | Drug: desipramine hydrochloride<br>* desipramine hydrochloride, with dose targeted to achieve a serum concentration of 5-60ng/ml<br>* Other names: Anafranil;|
| Experimental: Arm 2<br>cognitive behavioral therapy | Behavioral: cognitive behavioral therapy<br>* cognitive behavioral therapy, a type of psychotherapy oriented towards restoring function and reducing impact of pain on everyday life<br>|
| Experimental: Arm 3<br>desipramine hydrochloride and cognitive behavioral therapy | Drug: desipramine hydrochloride<br>* desipramine hydrochloride, with dose targeted to achieve a serum concentration of 5-60ng/ml<br>* Other names: Anafranil;Behavioral: cognitive behavioral therapy<br>* cognitive behavioral therapy, a type of psychotherapy oriented towards restoring function and reducing impact of pain on everyday life<br>|
| Placebo Comparator: Arm 4<br>anticholinergic medication; active placebo | Drug: benztropine mesylate 0.125 mg daily<br>* benztropine mesylate is a placebo, some of whose side effects mimic those of experimental intervention, desipramine hydrochloride<br>* Other names: Cogentin;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intent-toTreat Analysis of Descriptor Differential Scale (DDS) of Pain Intensity | The DDS is self-report measure of current pain intensity of chronic back pain. Participants rate pain on a 20 point scale as being greater or less intense relative to 12 adjectival descriptor words which serve as anchors (eg, greater or less than faint, moderate, strong). Scores range from 0 to 20 with higher scores indicating higher pain intensity. The analysis evaluated the 'as randomized' sample at 12 weeks after baseline or last observation carried forward, after co-varying for baseline (pre-treatment) values. | 12 weeks after baseline (or last observation carried forward) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Roland and Morris Disability Questionnaire | This questionnaire measures disability in everyday function due to back pain. It is a 24-item checklist asking patients to endorse whether or not back pain limits activities they normally do (eg, I stay at home most of the time because of my back). Scores range from 0 to 24, with higher scores indicating greater disability in everyday function due to back pain. The analysis evaluated the 'as randomized' sample at 12 weeks after baseline, after co-varying for baseline (pre-treatment) values. | 12 weeks after baseline (or last observation carried forward) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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chronic pain, back pain, antidepressants