Despite being a mood disorder of much prevalence, the exact causes of bipolar disorder are not fully understood. Medical and scientific researchers have grappled with the question of its causality for many decades, and even as there is much more scientific data and analysis to go upon today, satisfactory answers are yet to be found.

Though no specific determinants are labelled as being predominant in increasing proclivity to bipolarity, there is scholarly consensus over the fact that it is a combination of factors that lead to its incidence. Contemporary research suggests that the following play a vital role in being responsible for the condition:


Over the years, it has been established that there is some linkage between one’s genetic make up and the occurrence of bipolar disorder. Consider the following facts:

  • About half the people with this condition have at least one relative with a history of mood disorders.
  • An individual with one parent suffering from bipolarity is at 15-25% higher risk of having the condition.
  • Studies on twins have shown that a non-identical twin has a 25% higher risk of having the condition if his sibling suffers from it. Moreover, in identical twins, the risk is eight times more heightened.

Clearly, genetics play a role in rendering affected individuals more vulnerable. Scientific research is currently attempting to determine which genes are involved with the same.

Neurochemical Imbalances in the Brain

Bipolar disorder occurs in a specific part of the brain due to malfunctioning of some neurotransmitters. Neurotransmitters are chemicals responsible for allowing communication between brain cells. An imbalance in these naturally occurring neurochemicals has been found to play a significant role in causing several mood disorders including bipolarity.

It is believed that despite these chemical imbalances existing throughout, the disorder may remain dormant in an individual. It may get activated at a later stage, either by itself or due to psychological or social triggers.

Environmental Influences

It is perhaps environmental influences which are the most easily perceptible contributors to the incidence of bipolarity. Several environmental influences may cause the onset of the condition including:

  • A major life event, accident or occurrence may trigger bipolarity in an individual with a biological tendency towards the same.
  • Traumatic experiences are also known to have affected the psyche of prone individuals in a similar manner.
  • Links have been found between high alcohol consumption and substance abuse and the occurrence of bipolar disorder. Though it is unclear that either habit may be the primary cause of the condition, it is certainly known to enhance its severity and thus worsen the illness.
  • Some research also shows that individuals suffering from the condition have a genetic predisposition to anomalies in sleep-wake cycles. Also, problematic sleep cycles can worsen the illness by triggering mood episodes in many instances.


One may conclude that there is a wide range of environmental influences which may contribute to the onset of bipolarity. However, there is little homogeneity in the nature or effectiveness of either of these – different individuals react to varied triggers, with their being no dominant environmental factor having emerged most potent.


It is easy to see why scientists maintain that it is a combination of two or more factors that causes bipolar disorder to occur in human beings. There is little tangible evidence that any one of these factors – genetic, biological or environmental – may trigger bipolarity without other influences acting upon the individual. Therefore, what causes the condition is perhaps not as important as understanding the signs that are symptomatic of its occurrence. The latter allows for speedy diagnosis and treatment, thus allowing bipolar patients the potential for relief and resuscitation.