According to statistics, what proportions of US adults experience mental illness and serious mental illness respectively?

• A. 1 in 17; 1 in 5
• B. 1 in 3; 1 in 10
• C. 1 in 4; 1 in 6
• D. 1 in 5; 1 in 17

Answer: (D)

Understanding how common mental health conditions are among adults helps you gauge how often you might encounter someone with mental health needs and how the severity matters in how you respond. About one in five adults experience some form of mental illness in a given period, while serious mental illness affects a smaller share—roughly one in seventeen adults—referring to conditions that cause substantial impairment in daily functioning. This combination, around 20% for mental illness and about 6% for serious mental illness, aligns with widely cited statistics. Other options would imply a larger portion of the population is affected by serious mental illness or by mental illness in general, which isn’t what the major statistics show.