Mental disorders are illnesses that affect a person's thoughts, feelings and behaviors, preventing them from living a happy and productive life. There are several types of mental disorders including anxiety disorders, mood disorders like depression and bipolar disorder, eating disorders, conduct disorders, schizophrenia, and personality disorders. Symptoms vary but can include extreme feelings, disturbed thinking, and problematic behaviors. Treatment involves psychotherapy, group therapy, medication, and coping strategies to manage symptoms and improve functioning.