Studies of twins and families have shown that people with a first-degree relative (such as a parent, brother or sister) with bipolar disorder have a higher risk of developing bipolar disorder themselves than the general population.
However, it is important to note that genetics is only one of many factors contributing to the development of bipolar disorder, and other environmental and neurobiological factors may also play a role.
Several genes likely involved in bipolar disorder
There is not a single gene for bipolarity, but probably many genes, all associated with a very small increase in risk. On the other hand, it is known that overall heritability (i.e. the share of risk linked to genetic factors) is significant, probably between 60 and 85%.
Having relatives with bipolar disorder increases the risk of significant self-development (up to 10 times higher for first-degree relatives).
When a patient is diagnosed, the issue of bipolar disorder in the family or suicide should be a matter of routine.
Environmental Factors in Bipolar Disorders
There are also environmental factors, but also epigenetic factors, i.e. environmental factors that will change the expression of certain genes, which may be responsible for bipolar disorders.
Stress
Stress can trigger episodes of mania or depression in some people with bipolar disorder. Stressful events such as relationship problems, financial difficulties, or major life changes can play a triggering role.
Trauma
Traumatic events in childhood or adulthood, such as physical, sexual or emotional abuse, can increase the risk of developing bipolar disorder.
Substance Abuse
Excessive use of alcohol or drugs can aggravate the symptoms of bipolar disorder and make treatment more difficult.
Changes in sleep patterns
Disruptions in the sleep-wake cycle, such as sleep deprivation or changes in circadian rhythm, can trigger manic or depressive episodes in people with bipolar disorder.
Major life events
Events such as bereavement, job loss, relocation or other major life changes can have an impact on emotional balance and trigger episodes of mania or depression.
It is important to note that bipolar disorder is generally caused by a complex combination of genetic, environmental and neurobiological factors, and these factors can vary from person to person.