What causes bipolar disorder? 

No one knows exactly what causes bipolar disorder. Researchers suggest that a combination of different factors, including physical, environmental and social, increase your chance of developing the condition. 

On this page you can find information on: 

• childhood trauma 
• stressful life events 
• brain chemistry 
• genetic inheritance 

Childhood trauma 

Some experts believe that experiencing a lot of emotional distress as a child can cause you to develop bipolar disorder. This can include experiences like: 

• sexual or physical abuse 
• neglect 
• traumatic events 
• losing someone very close to you, such as a parent or carer 

This could be because experiencing trauma and distress as a child can have a big effect on your ability to regulate your emotions. 

Stressful life events 

You may be able to link the start of your symptoms to a very stressful period in your life, such as: 

• a relationship breakdown 
• money worries and poverty 
• experiencing a traumatic loss 

Although lower levels of stress are unlikely to cause bipolar disorder, for some people they can trigger an episode of mania or depression. 

(See our pages on managing stress for more information on the links between stress and mental health). 

Brain chemistry 

Evidence shows that bipolar symptoms can be treated with certain psychiatric medications, which are known to act on the neurotransmitters (messenger chemicals) in your brain. 

This suggests that bipolar disorder may be related to problems with the function of these neurotransmitters – and this is supported by some research. However, no one knows for certain exactly how these neurotransmitters work and whether problems with these are a cause or a result of bipolar disorder. 

Genetic inheritance 

If you experience bipolar disorder, you are more likely to have a family member who also experiences bipolar moods and symptoms (though they might not have a diagnosis). This suggests that bipolar disorder might be passed on through families. 

However, this does not necessarily mean that there is a ‘bipolar gene’ – family links are likely to be much more complex. For example, researchers think that environmental factors can also be triggers for experiencing symptoms of bipolar disorder. And for most people, family members are an influential part of your environment as you grow up. 

Can drugs cause bipolar disorder? 

Medication, drugs or alcohol can’t cause you to develop bipolar disorder, but they can cause you to experience some bipolar moods and symptoms. For example: 

• Some antidepressants can cause mania or hypomania as a side effect when you are taking them or as a withdrawal effect when you are coming off them. If you begin to experience mania after taking or after coming off antidepressants for depression, this might lead your doctor to give you an incorrect diagnosis of bipolar disorder, or prescribe you more medication. But in this case it’s usually worth waiting to see if your symptoms pass without treatment first. It is important to seek medical opinion even if this is the case, however, a formal diagnosis or longer term medication may not be required after thorough history of your symptoms. Some monitoring will be required until your symptoms lessen or subside.
• Alcohol or street drugs can cause you to experience symptoms similar to both mania and depression. It can often be difficult to distinguish the effects of alcohol and drugs from your mental health symptoms. 

If you’re concerned about the effects of medication, alcohol or street drugs on your mental health, it’s important to discuss it with your doctor. 

(See our pages on antidepressants and the mental health effects of alcohol and street drugs for more information.)