Elevated or low levels of the stress hormone cortisol are associated with depression and lower quality of life in bipolar patients, a new study from Umeå University in Sweden announced. The study found that depression is almost twice as common and poor quality of life is five times as common in people with bipolar disorder.
Bipolar disorder affects approximately 5.7 million adults in the US every year. People with bipolar disorder experience unusual shifts in mood, energy, activity levels, and ability to carry out day-to-day tasks. Previous studies confirmed that stress triggers bipolar episodes in patients. Mania and depression further contribute to the stress load experienced by people with bipolar disorder. The relationship between the stress system, depression, and quality of life, however, had not been examined until this study.
“In bipolar depression the stress system is often activated, which means that the affected individuals have elevated cortisol levels in the blood. We have now been able to show that both over- and underactivity in the stress system, with corresponding elevated or reduced cortisol levels, can impair mental health in terms of depression and poor quality of life in these patients,” said Umeå University PhD student Martin Maripuu.
The study examined the cortisol levels in 145 type one and two bipolar patients and matched them with 145 controls. Researchers used the Dexamethasone Suppression Test (DST) to measure cortisol levels in patients, the Beck Depression Inventory (BDI) and the Montgomery-Åsberg Depression Rating Scale (MADRS-S) to measure self-reported depression, and the World Health Organization Quality of Life Assessment–100 and the Global Assessment of Functioning to measure self-reported quality of life.
Depression was twice as common in bipolar patients with high and low cortisol levels, as compared to people with normal cortisol levels in their blood. Low quality of life was six times more common in patients with bipolar and low cortisol levels. It was five times more common in patients with bipolar and high cortisol levels. Additionally, patients with low cortisol have, on average, had their disorder for a longer period of time. This could mean that people with bipolar disorder experience chronic stress, which causes an “exhaustion” of the stress system, resulting in reduced cortisol levels.
What it Means
Though these new breakthroughs need additional research, this information could lead to a better understanding and better treatment of bipolar disorder. These researchers have shifted the focus of bipolar disorder treatment by suggesting that effective treatment of bipolar disorder should involve regulating and researching the stress system.
“The results may also ultimately lead to the development of new drugs that work by normalizing the stress system and cortisol levels,” said Maripuu.