Predicting comorbid mental health difficulties in people with autoimmune arthritis.

Little is known about variables impacting the association between mental health difficulties and autoimmune conditions. This study investigates whether, age of onset, adverse childhood experiences (ACEs), and 'illness invisibility' predict comorbid mental health difficulties in people with autoimmune arthritis. Participants with autoimmune arthritis (N = 209) were recruited via social media platforms. Age of onset of arthritis and the temporal order of mental health difficulties (if applicable) were collected alongside a measure of personality and ACEs. A novel measure of illness invisibility was developed for this study. A cross-sectional mixed-subject design was utilised. 53.5% of the sample endorsed lifetime mental health difficulties. Logistic regression analyses revealed participants with a younger age of onset of arthritis had significantly higher odds of developing a mental health problem (OR 0.93, 95% CI 0.90-0.96). Independently, Illness Invisibility, endorsed by 89.9% of participants, significantly predicted postmorbid mental health difficulties (OR 1.08, 95% CI 1.01-1.19). Adverse Childhood Experiences were frequently endorsed within the sample with 37.8% reporting ≥ 3 cumulative ACEs. Every unit increase in ACEs increased the odds of having comorbid mental health difficulties (OR 1.27, 95% CI 1.09-1.47). Young people who are diagnosed with autoimmune arthritis maybe more likely to experience subsequent mental health difficulties. The 'invisibility' of their illness and exposure to ACEs also is associated with their risk for mental health complications. These findings highlight the importance of mental health screening for young people being investigated for arthritis and interdisciplinary care, especially for young people.