Incidence of medication-treated depression and anxiety associated with long-term cancer, cardiovascular disease, diabetes and osteoarthritis in community-dwelling women and men

Background
Long-term cancer, cardiovascular disease, diabetes and osteoarthritis may increase the risk of mental disorders, but which was more harmful and whether the associations differed between genders is unclear.

Methods
We included 115,094 participants (54.3% women) aged 45–64 years from the 45 and Up Study who were free of depression, anxiety, and Parkinson's disease at baseline (2006–2009). The incidence of depression and anxiety was identified using claim databases during follow-up until December 2016. Cox regression models were used to examine the association of cancer, cardiovascular disease, diabetes, and osteoarthritis at baseline with incident depression and anxiety.

Findings
During a mean eight-year follow-up (958,785 person-year), the cumulative incidence of depression and anxiety was 12.5% and 5.9% in the healthy population. Hazard ratios ([HRs] (95% CI) versus healthy population) for incident depression associated with long-term cancer, cardiovascular disease, diabetes, and osteoarthritis were 1.19 (95% CI: 1.13–1.25), 1.08 (1.00–1.16)), 1.18 (1.09–1.28), and 1.94 (1.80–2.10), respectively. The corresponding HRs (95% CIs) for incident anxiety were 1.11 (1.03–1.20), 1.26 (1.14–1.39), 1.10 (0.98–1.24), and 2.01 (1.80–2.23), respectively. The positive association between cancer and incident depression was more evident in men (HR (95% CI): 1.24 (1.13–1.35) than in women (1.14 (1.07–1.21). Long-term diabetes was an independent risk factor for incident anxiety in men (1.21 (1.02–1.44) but not in women (1.09 (0.93–1.28)).

Interpretation
Long-term osteoarthritis, cardiovascular disease, and cancer were independent risk factors for incident depression and anxiety in both genders with osteoarthritis having the highest relative risk.