Mental illness covers a range of mental health conditions that affect mood, thinking, and behaviour. These conditions can include depression, anxiety disorders, schizophrenia, and bipolar disorder, among others. Mental illnesses can impact a person’s ability to function in daily life and may require treatment like therapy, medication, or lifestyle changes. They can result from genetic, biological, psychological, and environmental factors. Mental illnesses are defined and listed in the DSM and the ICD. The terms mental illness and mental disorder are often used interchangeably.