EFFECT OF CARBAMAZEPINE ON PAIN SCORES OF UNIPOLAR DEPRESSED-PATIENTSWITH CHRONIC PAIN - A TRIAL OF OFF-ON-OFF-ON DESIGN

Objective: The purpose of this study was to evaluate the effect of car bamazepine on chronic pain in patients with major depression. Design: Off-on-off-on carbamazepine treatment design. Setting: Department of A nesthesiology, Hirosaki University Hospital, Japan. Patients: Fifteen patients with a diagnosis of major depression and chronic pain. Interv ention: Depressed patients maintained on antidepressants that had fail ed to help depression or pain were initially placed on 450 mg carbamaz epine at 150 mg three times per day, Carbamazepine was then increased until the patients experienced satisfactory relief of pain. This dose was then maintained for 3 weeks. Afterward, the medication was stopped , and a lactose placebo was administered orally three times per day fo r 3 weeks. Thereafter, carbamazepine was given for 3 additional weeks at the dose that previously produced satisfactory pain relief. Outcome Measure: Pain scores were assessed four times during the course of th e study: before and after the first and the second treatments with car bamazepine, using a visual analog scale in which 0 represents ilo pain and 10 unbearable pain. The Hamilton Depression scale was used to jud ge improvement in the symptoms of depression. Results: Carbamazepine p roduced a statistically significant reduction in the pain scores, from 8.2 +/- 2.3 to 4.0 +/- 1.1 after the first treatment. The pain score significantly increased to 8.0 +/- 1.0 after stopping carbamazepine, b ut it decreased significantly to 4.1 +/- 1.8 after the second treatmen t. The Hamilton scores significantly decreased from 27.4 +/- 7.2 to 20 .2 +/- 6.1 after the carbamazepine treatment. Conclusions: These resul ts may indicate that carbamazepine has both an antidepressive and an a nalgesic action in depressed patients. Thus, carbamazepine may offer a n acceptable therapeutic option in depressed patients with chronic pai n that is unresponsive to antidepressants. Alternatively, these result s may indicate that carbamazepine appears to help depression in this g roup of pain patients because of its analgesic effect (i.e., helps dep ression as a result of helping pain or vice versa).