Does hair cortisol mediate the effects of sexual and gender minority stress on depression and anxiety? A structural equation modelling approach

BackgroundSexually and gender-diverse people are at an increased risk of experiencing depression and anxiety, which has been attributed to minority stress. The aim of this study was to investigate, for the first time, whether sexually and gender-diverse people exhibit altered hair cortisol concentrations, and whether this mediates the effects of minority stress on depression and anxiety.MethodsN=328 sexually and gender-diverse people and n=286 age- and BMI-matched cis-gender heterosexuals from the general Swiss population completed an online survey and collected a hair sample. Depression and anxiety were measured via the Patient Health Questionnaire (PHQ). Minority stress was assessed with a questionnaire covering discrimination, expected rejection, concealment, and internalised stigma. One centimetre of hair was analysed to determine past-month cortisol, using the gold standard liquid chromatography with tandem mass spectrometry.ResultsSexually and gender-diverse people had significantly higher levels of depression than cis-gender heterosexual people. Moreover, gender-diverse people had higher levels of anxiety and lower hair cortisol in comparison to sexually diverse and cis-heterosexual people. Among sexually and gender-diverse people, minority stress was positively associated with depression and anxiety. Moreover, internalised stigma was positively associated with hair cortisol.LimitationsDepression and anxiety were measured via a self-reported instrument (PHQ).ConclusionsThis study is the first to demonstrate that gender-diverse people experience increased levels of depression and anxiety while also exhibiting chronically lowered levels of cortisol, a profile seen in trauma-, fatigue, and pain-related conditions. These findings elucidate a mechanism potentially underlying some of the health disparities in this marginalised group.