Bipolar disorder, also known as manic-depressive illness, is a mental health condition that causes extreme mood swings that include emotional highs (mania or hypomania) and lows (depression).

It affects millions of people worldwide, and its causes have eluded scientists for decades. However, recent research by US scientists has uncovered seven potential causes of bipolar disorder.

1. Genetics

A genetic predisposition is one of the primary causes of bipolar disorder. Studies show that if one biological parent has bipolar disorder, the risk of developing the condition is 15-25%.

If both biological parents have the disorder, the risk increases to 50-75%. The genetic mutations that cause bipolar disorder affect the way brain cells communicate with each other and control mood regulation.

2. Neurotransmitter imbalances

Neurotransmitters are chemicals in the brain responsible for transmitting and modulating nerve impulses. Imbalances in dopamine, serotonin, and other neurotransmitters can lead to mood disorders like bipolar disorder.

Studies suggest that dopamine dysregulation may cause manic episodes, while serotonin deficiencies may contribute to depression in people with bipolar disorder.

3. Environmental triggers

Environmental triggers such as stress, trauma, and substance abuse can also contribute to the onset of bipolar disorder. Stressful life events like divorce, job loss, or bereavement can trigger the disorder in susceptible individuals.

Substance abuse, especially cocaine and amphetamines, can also trigger manic episodes in people with bipolar disorder.

4. Brain structural abnormalities

Neuroimaging studies have shown that people with bipolar disorder have differences in brain structure and function compared to those without the condition.

Abnormalities in the prefrontal cortex, amygdala, and hippocampus regions of the brain are implicated in bipolar disorder. These brain regions are responsible for regulating mood, impulse control, and cognitive function.

5. Sleep disruption

People with bipolar disorder often have disrupted sleep patterns. Sleep disturbance is a hallmark of bipolar disorder, and research suggests that it may be both a cause and consequence of the condition.

Sleep deprivation can induce manic episodes, whereas excessive sleep can trigger depressive episodes. Disrupted circadian rhythms, which regulate the sleep-wake cycle, may contribute to bipolar disorder.

6. Inflammation

Inflammation is an immune system response to infection or injury. However, chronic inflammation can damage cells and tissues and has been linked to numerous health conditions, including bipolar disorder.

Studies show that people with bipolar disorder have higher levels of inflammatory markers in their blood than those without the disorder. Inflammation can also affect neurotransmitter function and contribute to mood dysregulation in bipolar disorder.

7. Epigenetics

Epigenetics refers to changes in gene expression that occur without altering the underlying DNA sequence. Epigenetic modifications can be caused by environmental factors like stress and diet, as well as genetic factors.

Recent research suggests that epigenetic changes may play a role in the development of bipolar disorder. Studies have identified epigenetic modifications in genes involved in mood regulation, suggesting that they may contribute to the disorder.

Conclusion

Bipolar disorder is a complex mental health condition with multiple causes. While the exact cause of bipolar disorder remains unknown, recent research has uncovered several potential contributors to the disorder.

Further research is needed to better understand the biological and environmental factors involved in bipolar disorder and to develop better treatments for this debilitating condition.