Bipolar Causes

Possible causes of bipolar disorder

The exact causes of bipolar disorder are unknown but what causes some people to develop the condition is dependent on a variety of complex circumstances rather than resting on one primary factor. Scientists generally agree that a combination of biological and environmental factors play a role in creating the triggers that will bring about a major episode and the onset of bipolar disorder.

Possible Contributing Factors:


Genetic factors play a significant part in providing possible contributing factors for the incidence of bipolar disorder. These factors may account for up to 80% of the cause of the condition although this is far from conclusive. For example, if one parent has bipolar disorder than there is a 10% chance that one of their children will develop the disorder. If both parents have bipolar disorder, that likelihood rises to approximately 40%. However, it important to remember that there are probably many genes involved in developing the disorder. These genes interact with other contributing risk factors that make some individuals more vulnerable to the onset of episodes.


Possible environmental factors leading to the emergence of bipolar disorder are similar to those suggested for schizophrenia. Although it has also been suggested that a stressful or traumatic life event might provide the trigger for the onset of the condition, it is unlikely that stress itself is the sole cause of bipolar disorder.

Drug Misuse

Although contentious, some research suggests that substance misuse is related to the development of mental illness. It is likely that substance misuse may precipitate or worsen the symptoms and interfere in the treatment of a person with bipolar disorder. Drug abuse/dependence can also cause symptoms that can be confused with mania or hypomania while the obverse ‘coming down’ experience can trigger depressive episodes which may not be related to the onset of bipolar disorder.

Biochemical Factors

Some research suggests that certain biochemical imbalances in the brain are involved in the cause of bipolar disorder. This is related to the production of serotonin in the brain. Serotonin is one of the neurotransmitters in the brain (substances that allow communication between nerve cells) which strongly influences a person’s mood. It has been suggested by some studies that abnormal serotonin production can cause mood swings due to the effect of the chemical on other neurotransmitters. However, it is unlikely that serotonin is the only neurotransmitter involves or that it is the sole chemical factor in the onset of bipolar disorder.