No one, including psychiatrists and researchers, understands the exact cause of bipolar disorder.
Experts point to the fact that bipolar disorder runs in families as one clue to bipolar disorder’s origins. A genetic component is strongly suspected. Some progress into the disorder’s cause or causes has been made in the last decade. Life’s stresses and inappropriate attempts to cope with those stresses by using drugs and alcohol can make the disorder more difficult to manage or treat.
Changes in the levels of brain chemicals called neurotransmitters can help in describing what is occurring in the brain when a patient is bipolar. Exactly what is happening is not completely understood. Levels of noradrenaline and serotonin are associated with depression and bipolar disorder. It has also been shown that levels of a third neurotransmitter called serotonin have an affect on mood and mood disorders.
Is There a Genetic Link?
Scientists have pretty much concluded that bipolar disorder runs in families. Studies that used identical twins indicated that if one identical twin had bipolar disorder, the other twin had a greater chance of developing the condition. It wasn’t a given, however. This indicates that genetics have a role to play, but not the only one since the genes of identical twins are, in fact, identical. Other siblings in the same family also showed a somewhat weaker tendency to develop bipolar disorder. The chance of an identical twin (of the bipolar twin) to also develop bipolar disorder is about 40% to 70% according to the research.
Other studies uncovered the fact that children with one biological parent with bipolar I or bipolar II disorder had an increased likelihood for getting bipolar disorder. Oddly enough, the bipolar parents in the study who had attention-deficit/hyperactivity disorder (AD/HD) were more likely to have children with bipolar disorder — but not AD/HD.
Scientific findings also show that simple depression is more common in families where other individuals have bipolar disorder. Conversely children with one or more bipolar parents seem to possess a propensity to develop other psychiatric disorder such as ADHD, major depression, or substance abuse. Additionally if a child is raised in a home where parents exhibit the symptoms of bipolar disorder in a flamboyant manner it appears that they are more likely to develop bipolar disorder themselves, regardless of genetic factors.
Is Lack of Sleep a Cause?
Sleep loss may cause a bipolar episode such as mania (elation) in some patients. Yet sleep disturbance is more accurately described as a precipitator of bipolar disorder symptoms in persons who are already predisposed to developing the disorder as opposed to being a root cause. Evidence indicates that if a sleep-deprived person who is bipolar enters a manic state, their need for sleep actually decreases even more.
Does the Age of One’s Parents Increase the Risk of Bipolar Disorder?
Research seems to indicate that it does. It suggests that children born who are to older fathers are at increased risk of developing the disorder. This may add another piece to the puzzle beside genetic and environmental factors that influence risks factors for bipolar disorder.