123I-beta-CIT binding and recovery from depression. A six-month follow-up study

Eighteen depressive outpatients were investigated using single-photon emission computerized tomography (SPECT) with a high-affinity dopamine (DA) and serotonin transporter (SERT) specific radioligand, (123)I-labeled beta-CIT (2 beta-carbomethoxy-3 beta-(4-iodophenyl)-tropane). The patients were tested at the beginning of the study and on follow-up after six months. The severity of depression was evaluated using the 17-item Hamilton Rating Scale of Depression (HRSD). Eight of the eighteen patients had an HRSD score below the median (12 points) on follow-up, and they had a significantly greater increase in (123)I-beta-CIT binding in the midbrain region compared with those patients who did not recover (ANCOVA: F = 8.12; df = 1, 14; p = 0.013). These results indicate that recovery from depression is associated with an increase in (123)I-beta-CIT binding in the midbrain.