Abstract
The success of serotonin-selective reuptake inhibitors has lent support to the monoamine theory of major depressive disorder (MDD). This issue has been addressed in a number of molecular imaging studies by positron emission tomography or single-photon emission computed tomography of serotonin reuptake sites (5-HTT) in the brain of patients with MDD, with strikingly disparate conclusions. Our meta-analysis of the 18 such studies, totaling 364 MDD patients free from significant comorbidities or medication and 372 control subjects, revealed reductions in midbrain 5-HTT (Hedges' g=-0.49; 95% CI: (-0.84, -0.14)) and amygdala (Hedges' g=-0.50; 95% CI: (-0.78, -0.22)), which no individual study possessed sufficient power to detect. Only small effect sizes were found in other regions with high binding (thalamus: g=-0.24, striatum: g=-0.32, and brainstem g=-0.22), and no difference in the frontal or cingulate cortex. Age emerged as an important moderator of 5-HTT availability in MDD, with more severe reductions in striatal 5-HTT evident with greater age of the study populations (P<0.01). There was a strong relationship between severity of depression and 5-HTT reductions in the amygdala (P=0.01). Thus, molecular imaging findings indeed reveal widespread reductions of ?10% in 5-HTT availability in MDD, which may predict altered spatial-temporal dynamics of serotonergic neurotransmission. © 2014 ISCBFM.
Original language | English |
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Pages (from-to) | 1096-1103 |
Number of pages | 8 |
Journal | Journal of Cerebral Blood Flow and Metabolism |
Volume | 34 |
Issue number | 7 |
DOIs | |
Publication status | Published - 1 Jan 2014 |
Externally published | Yes |
Keywords
- 5-HT
- depression
- molecular imaging
- PET
- receptor imaging
- SPECT
ASJC Scopus subject areas
- Neurology
- Clinical Neurology
- Cardiology and Cardiovascular Medicine