AUTHOR=Keller Benjamin , Mestre-Pinto Joan-Ignasi , Álvaro-Bartolomé María , Martinez-Sanvisens Diana , Farre Magí , García-Fuster M. Julia , García-Sevilla Jesús A. , Torrens Marta , The NEURODEP Group , Fonseca F. , Mateus J. , Papaseit E. , Pérez-Mañá C. , Rodríguez-Minguela R. , Rossi P. , Tamarit C. , Vallecillo G. TITLE=A Biomarker to Differentiate between Primary and Cocaine-Induced Major Depression in Cocaine Use Disorder: The Role of Platelet IRAS/Nischarin (I1-Imidazoline Receptor) JOURNAL=Frontiers in Psychiatry VOLUME=8 YEAR=2017 URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2017.00258 DOI=10.3389/fpsyt.2017.00258 ISSN=1664-0640 ABSTRACT=

The association of cocaine use disorder (CUD) and comorbid major depressive disorder (MDD; CUD/MDD) is characterized by high prevalence and poor treatment outcomes. CUD/MDD may be primary (primary MDD) or cocaine-induced (CUD-induced MDD). Specific biomarkers are needed to improve diagnoses and therapeutic approaches in this dual pathology. Platelet biomarkers [5-HT2A receptor and imidazoline receptor antisera selected (IRAS)/nischarin] were assessed by Western blot in subjects with CUD and primary MDD (n = 16) or CUD-induced MDD (n = 9; antidepressant free, AD−; antidepressant treated, AD+) and controls (n = 10) at basal level and/or after acute tryptophan depletion (ATD). Basal platelet 5-HT2A receptor (monomer) was reduced in comorbid CUD/MDD subjects (all patients: 43%) compared to healthy controls, and this down-regulation was independent of AD medication (decreases in AD−: 47%, and in AD+: 40%). No basal differences were found for IRAS/nischarin contents in AD+ and AD− comorbid CUD/MDD subjects. The comparison of IRAS/nischarin in the different subject groups during/after ATD showed opposite modulations (i.e., increases and decreases) in response to low plasma tryptophan levels with significant differences discriminating between the subgroups of CUD with primary MDD and CUD-induced MDD. These specific alterations suggested that platelet IRAS/nischarin might be useful as a biomarker to discriminate between primary and CUD-induced MDD in this dual pathology.