Mental health disorders are clinically significant disturbances in an individual's thinking, emotional regulation, or behavior that are associated with significant distress or functional impairment. According to the World Health Organization, over 1 billion people globally are living with mental health disorders, making this a critical public health issue affecting individuals across all ages, socioeconomic backgrounds, and geographic locations.

Defining good mental health remains one of the most complex and nuanced questions in contemporary psychology and public health. There is no singular, universally agreed-upon answer—and this complexity is not a weakness, but rather a reflection of the profound reality that mental health is fundamentally multidimensional and culturally influenced.

Mental health conditions are not being diagnosed and treated at an increasing rate because of improved awareness alone—emerging evidence suggests that overlooked lifestyle and environmental factors may be contributing substantially to their prevalence.