Researchers are still trying to understand what causes mental illness. There is no one cause — it can happen due to a mix of factors including genetics, how your brain works, how you grew up, your environment, your social group, your culture and life experience.
Causes of mental illness:
Genetic factors: having a close family member with a mental illness can increase the risk. However, just because one family member has a mental illness doesn’t mean that others will.
Drug and alcohol abuse: illicit drug use can trigger a manic episode (bipolar disorder) or an episode of psychosis. Drugs such as cocaine, marijuana and amphetamines can cause paranoia.
Other biological factors: some medical conditions or hormonal changes.
Early life environment: negative childhood experiences such as abuse or neglect can increase the risk of some mental illnesses.
Trauma and stress: in adulthood, traumatic life events or ongoing stress such as social isolation, domestic violence, relationship breakdown, financial or work problems can increase the risk of mental illness. Traumatic experiences such as living in a war zone can increase the risk of post-traumatic stress disorder (PTSD).
Personality factors: some traits such as perfectionism or low self-esteem can increase the risk of depression or anxiety.
The human brain is extremely complicated. Some research suggests that mental health problems may be linked to a variation in certain brain chemicals (such as serotonin and dopamine), but no one really understands how or why. Arguments that someone’s brain chemistry is the cause of mental health problems are very weak.
But even though there’s no strong evidence to say that any mental health problems are caused by a chemical imbalance in our brains, you might find some people still use brain chemistry to explain them.
Reasons for this might include:
Some psychiatric medications work by acting on chemicals in the brain, and there’s lots of evidence to show that medication can be effective in treating some symptoms of mental health problems (although drugs don’t work the same way for everyone).
Mental health problems can feel very personal and be hard to understand, so the idea that there could be a distinct physical cause for difficult thoughts, feelings and behaviours might make it feel easier to talk openly about your experiences and ask for help.
It’s important to remember that just because we may not know exactly what causes someone to experience a mental health problem, this doesn’t mean that it is any less serious than any other illness, any less deserving of recognition and treatment, or any easier to recover from.