ABSTRACT
Few studies have assessed biomarkers for the differentiation of major depressive disorder (MDD) and bipolar disorder (BD). However, some elements of depression such as hormones and receptors of the renin-angiotensin-adrenal system (RAAS), the hypothalamus-pituitary-adrenal (HPA) axis, and history of early-life stress (ELS) could be considered for differential diagnosis. Therefore, this study aimed to assess aldosterone and cortisol levels, MR and GR gene polymorphisms, and ELS as potential biomarkers for differentiating MDD and BD. This study presents a case-control design. Groups comprised samples for genetic, cortisol, and aldosterone analysis: healthy control (HC; n = 113/97/103), MDD (n = 78/69/67) and BD (n = 82/68/65) subjects. Furthermore, all subjects were assessed for diagnostic screening, the severity of depression, and history of ELS by applying MINI-PLUS, GRID-HDRS, and CTQ, respectively. In addition, genotype and allelic frequencies of GR (N363S, R22/23K and BclI) and MR (MI180V and -2G/C) polymorphisms were evaluated via PCR. Our findings demonstrate that basal aldosterone levels may be a biomarker for differentiating BD and MDD. Furthermore, ELS affects the HPA axis in BD, cortisol may be considered a biomarker for distinguishing BD and MDD, but only in the absence of ELS, and, finally, history of ELS and MR-2G/C variant alleles are factors that contribute to the severity of depressive symptoms in MDD and BD.
ABSTRACT
This multicenter study estimated the prevalence of major depressive disorder (MDD) among emergency department patients in Latin America. To identify patients with MDD, we used a combination of DSM IV- criteria interview and a questionnaire screen including the center for Epidemiological Studies Depression Scale. We analyzed data from consecutive adult patients from hospitals in Argentina, Brazil, Chile, Colombia, and Mexico and described the demographic and health status differences between MDD and non-MDD patients. Prevalence of MDD ranges from 23.0 to 35.0%. The estimates are based on a total of 1,835 patients aged 18 years and over, with response rates of 83.0%. Compared to non-MDD patients, MDD patients were more likely to be middle-aged, female, smokers, of lower socioeconomic status, and to report a diagnosis of asthma or arthritis/rheumatism. Multivariate analysis identified a lower level of education, smoking, and self-reported anxiety, chronic fatigue, and back problems to be independently associated with MDD. Our data suggest that the prevalence of MDD is elevated among emergency department patients in Latin American countries. The integration of depression screening into routine emergency care merits serious consideration, especially if such screening can be linked to psychiatric treatment.
