Mental illness can arise for many different reasons, there is no single cause. Various factors can contribute to risk for mental illness, including: - Genetics and family history - A traumatic brain injury - Life experiences such as stress, grief, childhood or sexual abuse - Biological factors such as a chemical imbalances in the brain -Use of alcohol or recreational drugs, especially during adolescence - Isolation, loneliness, difficulty socializing - Having a serious medical condition such as cystic fibrosis or cancer Research suggests that multiple causes play a role in the development of a psychiatric condition. In addition, it is crucial to remember that mental disorders are not caused by character flaws, laziness or weakness. Mental illness is no one's fault and recovery is possible.