Melatonin And Bipolar Risks

Bipolar disorder is a severe mood disturbance that involves the presence of a least one manic episode. The Diagnostic and Statistical Manual of Mental Disorders characterizes mania as, "a distinct period of abnormally and persistently elevated, expansive, or irritable mood, lasting at least one week." The episode may also include maladaptive behaviors such as grandiosity, psychosis, promiscuity and excessive actions, such as spending huge amounts of money. Bipolar disorder can include depression, but it is not a diagnostic necessity. Given the serious nature of the disorder, doctors are interested in how external factors and risks, such as compounds like melatonin, may play a role its development.

What is Melatonin?

Melatonin is a hormone secreted by the pineal gland. It circulates in the fluid that flows around the brain and the spine and is responsible for setting the body's circadian rhythms. Circadian rhythms control such systems as sleep-wake cycles, body temperature and hormone levels. The amount of melatonin an individual produces is thought to be determined by how much light is detected by sensors in the eyes; when the sensors get the message that it is dark, the body responds by providing more of the compound. Given its relationship to basic physiological functions that are often disturbed in mood disorders, scientists are interested in the role of melatonin in bipolar disorder.

Melatonin and Mood

Since mental illnesses such as bipolar disorder tend to go in cycles, scientists were drawn to the circadian rhythm systems in the body to look for answers. In 2006, researchers in Malaysia examined the timing and production levels of melatonin in patients with bipolar disorder and seasonal affective disorder. Their results, which were published in the "World Journal of Biological Psychiatry" revealed that melatonin production and release was altered in patients with bipolar disorder. They go on to further explain that based on their data, they believe that bright light exposure in order to suppress excessive melatonin production may be a viable treatment.

Melatonin and Genetics

Mood disorders, especially bipolar disorder, are known to be genetic to various degrees. Since melatonin seems to play a role in mood, researchers at the University of Melbourne decided to investigate whether melatonin sensitivity itself was genetic, and therefore linked to the inheritability of mood disorders. They studied identical and fraternal twins by testing their levels of nocturnal melatonin secretion. Their results, which were published in a 2006 issue of the journal "Psychoneuroendocrinology," revealed that one twin's tendency to produce melatonin predicted the other twin's level, with identical twins more predictive than fraternal twins. The researchers hope that this will lead to using hormones as way to know who is at a greater risk for bipolar disorder.

Treatment Implications

Though research and clinical data validate the notion that melatonin plays a role in mood disorders such as bipolar, the risks and benefits of treatment using the compound were not fully developed as of 2011. There are many FDA approved medications, as well as valid psychological treatments, for mood disorder that a patient should discuss with his doctor.