Schizophrenia, bipolar order, anxiety disorder, hearing voices - these psychiatric terms have become part of everyday news. Do you know what they mean? A mental illness is a mental condition that disrupts a person's thinking, feeling, mood, ability to relate to others, and daily functioning. Having a better understanding of these conditions can reduce fear, help you play a role in reducing stigma, and allow you to act and intervene more quickly to help a friend or loved one exhibiting sudden or acute symptoms. Mental disorders are common worldwide, but they're treatable and manageable conditions. An estimated 26.2% of Americans ages 18 and older - about one in four adults - suffer from a diagnosable mental disorder in a given year, and over a lifetime, 50% will experience a mental health diagnosis.