PET Biomarker Study for Antidepressant Response Prediction in Major Depressive Disorder

Major depressive disorder has a prevalence of 4.7% in the general population and is ranked as the leading cause of disability worldwide . The efficacy of current antidepressants is limited, as 50-60% of patients do not achieve a sufficient response to treatment: 12% achieve only a partial response, while 19-34% do not respond at all . These uncertain clinical effects are only observed after several weeks of treatment . For better patient management, there is an urgent need to identify markers for predicting and monitoring therapeutic response. Psychiatrists at the Nancy Psychotherapeutic Center are about to launch a "MESANTIDEP" study, in which they will evaluate the electroretinogram as a biomarker for predicting and monitoring therapeutic response. In the literature, numerous studies have shown a pattern of carbohydrate hypometabolism characteristic of depression, identified by 18F-FDG brain PET/CT scans. Cerebral metabolism patterns predictive of antidepressant response have also been demonstrated in some clinical trials, with hypermetabolism of the anterior cingulate in responders; and more severe hypometabolism of the anterior cingulate , dorsolateral prefrontal cortex and premotor area in non-responders. However, the studies in the literature group together very heterogeneous populations, with a large proportion of patients not naïve to antidepressant treatment. The TEPDEP study described in this protocol would evaluate Positons Eission Tomography (PET) with flurodeoxyglucose labelled with fluor-18 (18F-FDG) brain as a biomarker for predicting antidepressant response in a treatment-naive patient population. It is planned to offer the PET/CT study to patients included in the SSRI arm of the MesantiDEP study. The hypothesis of this study is that 18F-FDG PET/CT could be a biomarker for predicting response to selective serotonin reuptake inhibitor (SSRI) antidepressants.