TUESDAY, May 19, 2026 (HealthDay News) -- Adults with poor mental health report worse self-rated overall health and more chronic illness, according to a study published online May 5 in PLOS Medicine.Margaret E. Kruk, M.D., M.P.H., from Washington University in St. Louis, and colleagues compared health system experience and quality of care among 32,419 adults with poor versus good mental health in 18 high-, middle-, and low-income countries. Data were obtained through nationally representative telephone, online, and in-person surveys in 2022 and 2023.The researchers observed variation in the prevalence of self-reported poor mental health, from 4.7 percent in Nigeria to 39.6 percent in China, with prevalence unrelated to national income per capita. In most countries, more women than men reported poor mental health. Worse self-rated overall health and more chronic illness were seen for people with poor mental health across all countries. Of those with poor mental health, 0.9 to 52.4 percent (Lao People's Democratic Republic and United Kingdom, respectively) had received mental health care in the past year. Lower patient activation, worse care quality, and lower confidence in the health system were reported by people with poor mental health."People with poor mental health had worse care, more unmet needs, and less trust in the system, regardless of where they lived," Kruk said in a statement.One author served on the Vaccines & Immune Therapies Effectiveness Evidence Scientific Advisory Committee of AstraZeneca.Abstract/Full Text.Sign up for our weekly HealthDay newsletter