Early decrease in density of mononuclear leukocyte beta-adrenoceptors in depressed patients following amineptine treatment: possible relation to clinical efficiency.

1. The effect of chronic amineptine treatment (200mg/day) on beta-adrenoceptor density of intact mononuclear leukocytes (MNL) was examined in unmedicated major unipolar depressed patients. 2. Pretreatment parameters of (-)-[125I]-iodopindolol specific binding did not differ significantly from age- and sex-matched healthy controls as the patients were only moderately depressed. 3. All patients showed a highly significant clinical improvement as assessed by the AMDP-depression scale after one week of amineptine (D7), while 2 patients relapsed after one month of treatment (D28) and were considered to be non-responders. 4. The maximal density of beta-adrenoceptors (Bmax) was significantly decreased at D7 (by 33%) compared to pretreatment level (D0) in the treatment responders and remained lower at D28, although the difference was no longer significant. No alteration in beta-receptor affinity (Kd) was detected during the treatment. 5. These results indicate that treatment with amineptine, an antidepressant drug known to selectively inhibit the dopamine uptake system, can rapidly affect MNL beta-adrenoceptors. 6. Moreover, the present findings show that the reduction in MNL beta-adrenoceptor density, which is associated with a stable clinical improvement, may provide a predictive index for successful antidepressant treatment.