Effect of Antidepressants on Back Pain

Efficacy of Antidepressants in Chronic Back Pain

The purpose of this study is to determine whether different types of antidepressant medicines relieve back pain that has lasted at least six months on a daily basis. Study participants will be assigned to treatment with either a antidepressant acting on the serotonin system in the brain (fluoxetine), one acting on the noradrenaline system (desipramine, or to a control medication not expected to relieve pain (benztropine). Each participant will be seen at least nine times during their 12 weeks on medication. This is a phase 2/3, outpatient study.

Inclusion Criteria:

• Chronic back pain (pain on a daily basis for six months or longer)
• Age 18-65
• No major medical illness

Exclusion Criteria:

• medical contraindication to tricyclic antidepressants
• recent alcohol or substance use disorder
• bipolar disorder