Bipolar Patients with Disrupted Cortisol Report Poorer Quality of Life
Mania, Depression and Stress
The person with bipolar disorder may react to triggers with mania or an episode of hyper-positivity. For a time, the person may feel highly energetic, be overly talkative, perhaps aggressive or at least overly confident. This over-confidence can lead to increased productivity in the workplace or at school, but it also often leads to risk-taking behaviors such as reckless driving, overspending or casual sex.
At other times the person will enter into periods of debilitating depression during which they find it overwhelming to perform even the most trivial tasks. There are two forms of bipolar depression (bipolar I and II) based upon how strongly the manic episodes manifest. Patients with bipolar II may experience periods of high energy and confidence along with depressive episodes, but they are less disruptive than those associated with bipolar I. In either case, stress can trigger episodes, and the episodes themselves can create added stress.
The body is equipped to handle stress. In the presence of stress, the body releases stress hormones like cortisol. Stress hormones help all of us to cope with intense situations in life. However, if the stress is chronic and persists for a long time it can weaken the stress response, meaning that not enough cortisol will be produced and released. Repeated studies have shown that bipolar patients have chronically activated stress response systems.
A Study in Sweden
Researchers at Umea University in Sweden took a close look at cortisol levels in patients with bipolar disorder. The team examined 145 bipolar patients and 145 healthy control subjects. Investigators first measured cortisol levels in all the study participants during normal conditions. They then took another cortisol reading following a test (dexamethasone suppression) designed to detect early problems with stress responsiveness.
The researchers discovered that over 50 percent of bipolar patients had either high or low cortisol blood levels and were also depressed. Interestingly, it wasn’t only patients with too little cortisol who experienced negative outcomes. Whether the patient’s cortisol level was high or low, patients with abnormal levels were two times more likely to be depressed versus patients with cortisol levels in the normal range.
There were slight differences depending upon whether cortisol was too high or too low, however. Bipolar patients with lower than normal cortisol levels were six times more likely to experience a low quality of life compared to those with normal cortisol levels. Those patients with higher than normal cortisol experienced low quality of life five times more often than normal range cortisol patients. Thus, having too much or too little of the stress hormone increases the risk for depression and a low quality of life, though having too little cortisol is somewhat worse in terms of outcomes.
A Vicious Cycle
Investigators noted that patients who had lived with bipolar disorder for a longer period of time tended to be the ones with low cortisol levels. This might be evidence that bipolar disorder exhausts the stress response system. Initially, some bipolar patients may respond to stress by over-releasing cortisol, but over time the system wears out and begins producing too little of the hormone. The problem being that low cortisol may be part of what perpetuates the illness.
Here is what the researchers learned. Bipolar patients with abnormal cortisol levels face some higher risks. They are five times more likely to report a poor quality of life and two times more apt to be depressed. The study findings appeared in the professional journal PLOS ONE.