Depression is a genetic and phenotypic complex psychiatric disorder with a lifetime prevalence of 15-20%1-3. It is often recurrent and accompanied by considerable morbidity and co-morbidity, excess mortality, increased risk of suicide and substantial costs worldwide4-8. Individuals diagnosed with depression have an increased risk of developing practically all other types of mental disorders, in particular anxiety, bipolar disorder, schizophrenia and substance use disorder (SUD)9,10. This relationship is generally bi-directional (i.e. a significantly increased risk of comorbidity between depression and other types of psychiatric disorders, regardless of whether depression is diagnosed before or after a comorbid psychiatric disorder).
