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.

Inclusion criteria

• Patient aged 18 and over, included in the MESANTIDEP study for whom SSRI ( Selective serotonin reuptake inhibitor) treatment is planned.
• Patient who has received full information on the organization of the research and has given written informed consent (or a third person, independent of the investigator and sponsor, in the event of inability to read or write),
• Patient affiliated to a social security scheme or beneficiary of such a scheme

Exclusion criteria

• Contraindications for 18F-FDG PET/CT scans
• Presence of chronic neurological or psychiatric pathologies pre-Covid-19