There are a plethora of biological, environmental, and societal factors that lead to the development of mental health conditions. A few factors that may cause you to have a mental illness include: - Childhood abuse - Childhood trauma - Childhood neglect - Domestic violence - Bullying - Trauma as an adult - Emotional, physical, or sexual abuse - Genetics - A family history with mental illness - Traumatic brain injury - Neurological conditions - Substance abuse - Lifestyle - Homelessness - Unemployment - Chronic pain - Loneliness - Discrimination