1. Individuals with rheumatoid arthritis or axial spondyloarthritis have an increased risk of developing mood and anxiety disorders.
2. Rheumatoid arthritis was inversely associated with schizophrenia and Alzheimer's disease.
3. The risk of depression was highest in those diagnosed before age 40.
4. Further investigation into the roles of inflammatory cytokines and treatment-related effects is needed. 

Source: BMJ Mental Health