A study of UK data from more than 1.5m people suggests that having an autoimmune disease could almost double the risk of mental health conditions, including depression, anxiety and bipolar disorders, with scientists recommending that future work should seek to investigate potential causal mechanisms for these associations.
The Edinburgh University researchers said the link might be explained by the chronic exposure to systemic inflammation caused by the autoimmune disease.
A growing body of evidence suggests inflammation is linked to mental ill health, but many of the published studies have relied on small sample sizes, limiting their statistical power, reports The Guardian.
To overcome this, the study team drew on data from 1.5m people in the Our Future Health programme from across the UK. Participants completed a questionnaire asking for personal, social, demographic, health and lifestyle information.
Health information included lifetime diagnoses for disorders including autoimmune and psychiatric conditions. Six autoimmune conditions were included in the study: rheumatoid arthritis, Graves’ disease (thyroid hormone disorder), inflammatory bowel disease, lupus, multiple sclerosis and psoriasis.
The mental health conditions the researchers were interested in were self-reported diagnoses of affective disorders, defined as depression, bipolar or anxiety disorder.
In total, 37 808 people reported autoimmune conditions and 1 525 347 did not.
The researchers said the lifetime prevalence of any diagnosed affective disorder was significantly higher among those with an autoimmune disorder than it was among the general population: 29% against 18%.
Similar associations emerged for depression and anxiety: 25.5% compared with just more than 15% for depression, and more than 21% compared with 12.5% for anxiety. Current depression and anxiety was also higher among people with autoimmune conditions.
While the prevalence of bipolar disorder was much lower, it was still significantly higher among those with autoimmune disorders than among the general population: just under 1% compared with 0.5%.
The prevalence of affective disorders was also significantly and consistently higher among women with autoimmune disorders than among men with the same physical health conditions: 32% compared with 21%.
The reasons are unclear, said the researchers, whose findings were published in the BMJ Mental Health journal, but theories suggest that sex hormones, chromosomal factors, and differences in circulating antibodies may partly explain the differences.
Overall, the risk for mental health conditions was nearly double in people with autoimmune conditions – between 87% and 97% higher. It remained high even after adjusting for potentially influential factors, including age, household income and parental psychiatric history.
The study was limited by a lack of available information on the time or duration of illness, making it impossible to determine whether autoimmune conditions preceded, co-occurred with or followed affective disorders.
No direct measurements of inflammation were made either, making it impossible to establish the presence, nature, timing or severity of inflammation.
“Although the observational design of this study does not allow for direct inference of causal mechanisms, this analysis … suggests chronic exposure to systemic inflammation may be linked to a greater risk for affective disorder,” they said.
“Future studies should seek to determine whether putative biological, psychological, and social factors – for example, chronic pain, fatigue, sleep or circadian disruptions and social isolation – may represent potentially modifiable mechanisms linking autoimmune conditions and affective disorders.”
They suggested it might be worth regularly screening people diagnosed with autoimmune diseases for mental health conditions, especially women, to provide them with tailored support early on.
Study details
Affective disorders and chronic inflammatory conditions: analysis of 1.5 million participants in Our Future Health
Arish Mudra Rakshasa-Loots, Duncan Swiffen, Christina Steyn et al.
Published in BMJ Mental Health on 10 June 2025.
Abstract
Background
Chronic inflammation is associated with psychiatric disorders. If inflammation is linked mechanistically to mental health, people living with chronic inflammatory conditions may experience mental health issues at higher rates than others.
Objective
To test this hypothesis, we analysed data from 1 563 155 adults living in the UK within the newly launched UK-wide Our Future Health research cohort.
Methods
Participants were split between two groups: people with self-reported lifetime diagnoses of six autoimmune conditions (n=37 808) and those without these diagnoses (n=1 525 347).
Findings
Lifetime prevalence (95% CI) of self-reported lifetime diagnoses of any affective disorder (depression, bipolar disorder, anxiety) was significantly higher (p<0.001) among people with autoimmune conditions (28.8% (28.4% to 29.3%)) than in the general population (17.9% (17.8% to 18.0%)), with similar trends observed for individual affective disorders. Prevalence of current depressive symptoms (9-item Patient Health Questionnaire (PHQ-9) ≥10, 18.6% vs 10.5%) and current anxiety symptoms (7-item Generalised Anxiety Disorder Scale (GAD-7) ≥8, 19.9% vs 12.9%) was also higher among people with autoimmune conditions. Odds of experiencing affective disorders, calculated using logistic regression models, were significantly higher in this group compared with the general population (OR (95% CI) = 1.86 (1.82 to 1.90), p<0.001), and these odds remained elevated when adjusting for the effects of age, sex, ethnicity (OR=1.75 (1.71 to 1.79), p<0.001) and additionally, for household income, parental history of affective disorders, chronic pain status and frequency of social interactions (OR=1.48 (1.44 to 1.52), p<0.001).
Conclusions
Overall, the risk of affective disorders among people living with autoimmune conditions was nearly twice that of the general population.
Clinical implications
Although the observational design of this study does not allow for direct inference of causal mechanisms, this analysis of a large national dataset suggests that chronic exposure to systemic inflammation may be linked to a greater risk for affective disorders. Future work should seek to investigate potential causal mechanisms for these associations.
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