Definitive DSM-5-TR diagnosis list by Hannah DeWitt | Jan 8, 2026 | Disorders, Mental Health Topics Mental disorders are health conditions that impact a person’s thinking, emotions, or behavior—or some combination of the three. They can cause distress and/or impair one’s ability to function, whether that be socially, occupationally, or in some other dimension of life. According to the National Institute of Mental Health (NIMH), about…