Most mental illnesses don’t have a single cause. Instead they have a variety of causes, called risk factors. The more risk factors you have, the more likely you are to develop a mental health condition. Sometimes, mental illness develops gradually. Other times, it doesn’t appear until a stressful event triggers it.

There are many risk factors and triggers, but here are a few examples:

• Genetics. Mental illness often runs in the family.
• Environment. Living in a stressful environment can strain your mental health. Things like living in poverty or having an abusive family put a lot of stress on your brain and often trigger mental health concerns.
• Stressful events: like losing a loved one, or being in a car accident.
• Childhood trauma. Even if you’re no longer in a stressful environment, things that happened to you as a child can have an impact later in life. Complex PTSD is one particularly common mental health condition among people who grew up in abusive or neglectful environments.
• Negative thoughts. Constantly putting yourself down or expecting the worst can get you stuck in a cycle of depression or anxiety.
• Unhealthy habits: like not getting enough sleep, or not eating.
• Drugs and alcohol: Abusing drugs and alcohol can be bad for your mental health. It can also make it harder to recover from mental illness.
• Brain chemistry. Mental illness often involves an imbalance of natural chemicals in your brain and your body.

These risk factors don’t just affect who will develop a mental illness in the first place. They also affect how severe their symptoms will be, and when they will experience those symptoms.

You can also improve your own mental health by taking action to reduce your risk factors. That might include seeking treatment, like medication or therapy.