[11C]Mirtazapine binding in depressed antidepressant nonresponders studied by PET neuroimaging

Psychopharmacology (Impact Factor: 3.99). 09/2009; 206(1):133-140. DOI: 10.1007/s00213-009-1587-3

ABSTRACT RationaleLack of benefit from antidepressant drug therapy is a major source of human suffering, affecting at least 25% of people with
major depressive disorder. We want to know whether nonresponse to antidepressants can be linked to aberrant neuroreceptor

ObjectiveThis study aims to assess the antidepressant binding in brain regions of depressed nonresponders compared with healthy controls.

Materials and methodsHealthy volunteers and depressed subjects who had failed to benefit from at least 2 antidepressant treatments were recruited
by newspaper advertisements. All subjects had received no antidepressant medication for at least 2months before positron
emission tomography (PET) that was carried out with [11C]mirtazapine. Kinetic parameters of [11C]mirtazapine were determined from PET data in selected brain regions by the simplified reference tissue model.

ResultsBinding potentials of [11C]mirtazapine in cerebral cortical regions were lower in depressed nonresponders than in healthy controls. Removal rates of
[11C]mirtazapine were higher in diencephalic regions of depressed nonresponders than in healthy controls.

ConclusionsPET neuroimaging with [11C]mirtazapine showed aberrant neuroreceptor binding in brain regions of depressed subjects who had failed to benefit from
treatment with antidepressant drugs.

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