False dogmas in mood disorders research:Towards a nomothetic network approach

The current understanding of major depressive disorder(MDD)and bipolar disorder(BD)is plagued by a cacophony of controversies as evidenced by competing schools to understand MDD/BD.The DSM/ICD taxonomies have cemented their status as the gold standard for diagnosing MDD/BD.The aim of this review is to discuss the false dogmas that reign in current MDD/BD research with respect to the new,data-driven,machine learning method to model psychiatric illness,namely nomothetic network psychiatry(NNP).This review discusses many false dogmas including:MDD/BD are mind-brain disorders that are best conceptualized using a bio-psycho-social model or mind-brain interactions;mood disorders due to medical disease are attributable to psychosocial stress or chemical imbalances;DSM/ICD are the gold standards to make the MDD/BD diagnosis;severity of illness should be measured using rating scales;clinical remission should be defined using threshold values on rating scale scores;existing diagnostic BD boundaries are too restrictive;and mood disorder spectra are the rule.In contrast,our NNP models show that MDD/BD are not mind-brain or psycho-social but systemic medical disorders;the DSM/ICD taxonomies are counterproductive;a shared core,namely the reoccurrence of illness(ROI),underpins the intertwined recurrence of depressive and manic episodes and suicidal behaviors;mood disorders should be ROI-defined;ROI mediates the effects of nitro-oxidative stress pathways and early lifetime trauma on the phenome of mood disorders;severity of illness and treatment response should be delineated using the NNP-derived causome,pathway,ROI and integrated phenome scores;and MDD and BD are the same illness.