The article explores the relationship between mental illness and mental health across the lifespan using the two continua model. Mental health is defined as a state of well-being where individuals realize their potential, cope with life's stresses, and contribute to their communities. It includes emotional, psychological, and social well-being. Mental illness, on the other hand, refers to the presence of psychopathological symptoms. The two continua model suggests that mental illness and mental health are related but distinct dimensions. A cross-sectional survey of Dutch adults (N = 1,340) found that older adults, except the oldest-old, scored lower on psychopathological symptoms and were less likely to be mentally ill than younger adults. However, older adults experienced more emotional well-being, similar social well-being, and slightly lower psychological well-being. These findings support the two continua model, indicating that mental illness and mental health follow different age trajectories. The study also examined mental health and illness across different age groups. It found that older adults generally experience fewer mental illness problems but do not have better positive mental health than younger adults. The results suggest that mental illness and mental health are qualitatively different dimensions. The study used the Mental Health Continuum—Short Form (MHC-SF) to measure mental health and the Brief Symptom Inventory (BSI) to measure mental illness. The findings support the two continua model, showing that mental illness and mental health are distinct but related constructs. The study concludes that older adults experience fewer mental illness problems than younger adults, but they do not have better positive mental health. The findings highlight the importance of considering both mental illness and mental health when studying well-being across the lifespan. The two continua model provides a framework for understanding the complex relationship between mental illness and mental health.The article explores the relationship between mental illness and mental health across the lifespan using the two continua model. Mental health is defined as a state of well-being where individuals realize their potential, cope with life's stresses, and contribute to their communities. It includes emotional, psychological, and social well-being. Mental illness, on the other hand, refers to the presence of psychopathological symptoms. The two continua model suggests that mental illness and mental health are related but distinct dimensions. A cross-sectional survey of Dutch adults (N = 1,340) found that older adults, except the oldest-old, scored lower on psychopathological symptoms and were less likely to be mentally ill than younger adults. However, older adults experienced more emotional well-being, similar social well-being, and slightly lower psychological well-being. These findings support the two continua model, indicating that mental illness and mental health follow different age trajectories. The study also examined mental health and illness across different age groups. It found that older adults generally experience fewer mental illness problems but do not have better positive mental health than younger adults. The results suggest that mental illness and mental health are qualitatively different dimensions. The study used the Mental Health Continuum—Short Form (MHC-SF) to measure mental health and the Brief Symptom Inventory (BSI) to measure mental illness. The findings support the two continua model, showing that mental illness and mental health are distinct but related constructs. The study concludes that older adults experience fewer mental illness problems than younger adults, but they do not have better positive mental health. The findings highlight the importance of considering both mental illness and mental health when studying well-being across the lifespan. The two continua model provides a framework for understanding the complex relationship between mental illness and mental health.