Bipolar disorder - Causes 

Causes of bipolar disorder 

The exact cause of bipolar disorder is unknown. Experts believe there are a number of factors that work together to make a person more likely to develop the condition.

These are thought to be a complex mix of physical, environmental and social factors.

Chemical imbalance in the brain

Bipolar disorder is widely believed to be the result of chemical imbalances in the brain.

The chemicals responsible for controlling the brain's functions are called neurotransmitters and include noradrenaline, serotonin and dopamine.

If there is an imbalance in the levels of one or more neurotransmitters, a person may develop some symptoms of bipolar disorder.

For example, there is evidence episodes of mania may occur when levels of noradrenaline are too high, and episodes of depression may be the result of noradrenaline levels becoming too low.


It is also thought bipolar disorder is linked to genetics, as the condition seems to run in families. The family members of a person with the condition have an increased risk of developing it themselves.

However, no single gene is responsible for bipolar disorder. Instead, a number of genetic and environmental factors are thought to act as triggers.


A stressful circumstance or situation often triggers the symptoms of bipolar disorder. Examples of stressful triggers include:

These types of life-altering events can cause episodes of depression at any time in a person's life.

Bipolar disorder may also be triggered by physical illness, sleep disturbances and overwhelming problems in everyday life, such as problems with money, work or relationships.

Page last reviewed: 08/04/2014

Next review due: 08/04/2016


How helpful is this page?

Average rating

Based on 135 ratings

All ratings

Add your rating


The 3 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Goddess Kyria said on 21 May 2014

sorry - missed some bits out - work told me my lateness reason and that i could not guarantee not being late again atm was unacceptable. Then I was given aletter saying I am attend a disciplinary meeting on friday!!!!!!!!!!!!!!! Today I am going tomy gp asap and will get signed off - for goodness knows how long. I did not want that to happen, I wanted to work, do work at home even, anything - they are busy and I don't want to let them down, and it is a good routione for me going into work each day. But I'm obviously not well enough to work, and after their treatment of me s*d them, quite frankly!!!!!!! Watch out for my book - I'm planning to call it something like 'the story of me/a celebration of mental illness'. Good luck with your journeys everyone - never give up hope :-) xx

Report this content as offensive or unsuitable

Goddess Kyria said on 21 May 2014

I have been diagnosed with Bipolar and Borderline Personality Disorder. The treatment of people with mental issues by the NHS is quite frankly appalling. I will be writing a book about my experiences (I have already written letters) which I hope will help those in power, DRs etc to understand us better. To see we are normal!!! We just are a bit different to 'normal' society members. The more I meet of mental patients the more I think we are the normal ones, its the drs and society that are the real mad ones, hahaha. Ooop, better be careful will be sectioned again saying 'irrational' and 'paranoid' things like that!!! I narrowly avoided being sectioned last night. Instead I was given a very painful shot of diamazepan which helped calm me - but I still have not had any sleep!!! Not sleeping is a huge trigger for me going hypomanic. I was also triggered (I had a mini hypomanic episode in the toilets at work yesterday) after receiving an email from my therapist asking me to stop emailing her unless it was relevant to therapy. If she had bothered to look at my emails properly she would have realised they are very relevant to my therapy - and I had already explained I was sorry for sending so many but they explain quicker what's going on - they were probably the equivalent of 5 therapy sessions?!! She isn't NHS, don't be silly good therapy available on NHS??!!! No, just give us drugs to keep us quiet and mask the problems. The other trigger was work (I had told them I was bipolar, a trigger was not sleeping, and that I was currently having trouble sleeping) they then questioned my long comfort break, told me my reason for lateness that morning was(which i gave as the truth - i had been talking to my parents about very upsetting personal issues) and my statement that I could not guarantee further lateness atm (because I was ill) I wobbled, but managed not to completely lose it in the office (therapy is helping me to learn techniques to calm myself down)....

Report this content as offensive or unsuitable

bermudj said on 19 January 2012

I have Bipolar-I. What triggers it is either medication which has such side effects, or worry. In your article you mention that the trigger could be problems in everyday life. That to me is looking at it from the outside. From the inside is worry. Now we may worry about different issues, money, family, and so on. I only have had two episodes. One came from medication for a hiatus hernia. The other was worry that I would not be able to find work. This came about from being a very shy man that always did quite bad at job interviews. The interesting aspect about this incident was that at the time I had £140.000, nevertheless the worry was so great that it triggered the illness. So to me it is the worry of how to handle the future. So it could be that one has no money and one worries how to handle the future without money and then it triggers the illness.

Report this content as offensive or unsuitable