Decreased brain serotonin 5-HT1A receptor availability in medication-naive patients with major depressive disorder: an in-vivo imaging study using PET and [carbonyl-11C]WAY-100635.
Serotonin (5-HT) is involved in the pathophysiology of major depressive disorder (MDD). Among the numerous serotonergic receptors, the 5-HT1A receptor subtype is of interest because of its involvement in cognition, hippocampal neurogenesis, and mechanism of action of antidepressant drugs. Previous imaging studies have suggested altered availability of 5-HT1A receptors in MDD but prior antidepressant medication and chronicity of the illness may confound the interpretation. We examined 21 drug-naive primary-care patients with MDD using positron emission tomography (PET) imaging with [carbonyl-11C]WAY-100635, a radioligand for 5-HT1A receptors, along with 15 healthy control subjects. Binding to receptors was assessed both regionally and at voxel level with the binding potential (BP) that was estimated using arterial blood input. Compared with healthy controls, the BP of [carbonyl-11C]WAY-100635 was reduced in patients with MDD in most brain regions, ranging from -9% to -25%. Voxel-level analysis confirmed this finding by showing a widespread reduction of [carbonyl-11C]WAY-100635 BP. No statistically significant associations were observed between BP and total HAMD scores in the patients, but lower BP was associated with higher likelihood of insomnia. This study demonstrated a widespread reduction in the availability of serotonin 5-HT1A receptors in a relatively large sample of drug-naive primary-care patients with MDD, suggesting the involvement of this receptor subtype in the pathophysiology of the illness. Lack of correlation with overall severity of the illness may relate to a largely trait-like nature of this abnormality in depressive disorders.
Hirvonen
Jussi
J
Department of Psychiatry, Turku PET Centre, University of Turku and Turku University Central Hospital, Turku, Finland. jueshi@utu.fi
Karlsson
Hasse
H
Kajander
Jaana
J
Lepola
Antti
A
Markkula
Juha
J
Rasi-Hakala
Helena
H
Någren
Kjell
K
Salminen
Jouko K
JK
Hietala
Jarmo
J
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D001923:Brain Chemistry / Q000187:drug effects*; D003865:Major Depressive Disorder / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D010879:Piperazines; D049268:Positron-Emission Tomography; D011569:Psychiatric Status Rating Scales; D011725:Pyridines; D044282:Receptor, Serotonin, 5-HT1A / Q000187:drug effects*; D012702:Serotonin Antagonists
D010879:Piperazines; D011725:Pyridines; D012702:Serotonin Antagonists; C112544:desmethyl-WAY 100635; D044282:Receptor, Serotonin, 5-HT1A