A large study shows that having bipolar disorder is associated with a four- to six-fold increased risk of dying prematurely, suggesting that more preventative efforts are needed.
Summary Comparative Mortality Risks in Two Independent Bipolar Cohorts Goals Compare mortality rates in bipolar disorder with common causes of mortality. Methods Observational data from the Prechter Longitudinal Study of Bipolar Disorder (PLS-BD) from 1,128 participants, including 281 controls, were analyzed using logistic regression to quantify mortality rates compared to comorbidities and common causes of death. Outcome and treatment measures, including ASRM, GAD-7, PHQ-9, and medication use, were used to stratify individuals with bipolar disorder (BD) who are alive or deceased. A larger cohort of 10,735 existing TB patients with 7,826 controls (without a psychiatric diagnosis) from the University of Michigan Health (UM Health) clinics was used as observational and replication secondary data analyses. Results Mortality rates are significantly different between those with BD and controls in both PLS-BD and UM Health. Those with TB and who have died have a higher percentage of elevated depression measures , but show no differences in measures of mania or anxiety or in patterns of medication use . In both cohorts, a diagnosis of bipolar disorder (BD) increases the odds of mortality to a greater extent than a history of smoking or being older than ≥60 years. Conclusion Bipolar disorder (BD) was found to significantly increase the odds of mortality and beyond smoking history. This finding was replicated in an independent sample. |
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Having bipolar disorder (a serious mental illness that can cause both manic and depressive moods) can make life more challenging.
It also carries a higher risk of dying prematurely. Now, a study puts into perspective how big that risk is and how it compares to other factors that can shorten life.
In two different groups, people with bipolar disorder were four to six times more likely to die prematurely than people without the disease, according to the study.
In contrast, people who had ever smoked were about twice as likely to die prematurely as those who had never smoked, whether or not they had bipolar disorder.
A team from the University of Michigan, home of one of the world’s largest long-term studies of people with bipolar disorder, reports their findings in the journal Psychiatry Research .
The stark difference in mortality and the differences in health and lifestyle that likely contributed to it should prompt more efforts to prevent premature deaths, the researchers say.
"Bipolar disorder has long been considered a risk factor for mortality , but always through the lens of other common causes of death," said Anastasia Yocum, Ph.D., lead author of the study and data manager at the Heinz C. Prechter Bipolar Research Program .
"We wanted to look at it on its own in comparison to conditions and lifestyles that are also linked to higher rates of premature death."
Two big data sources show similar results
Yocum and his colleagues, including Prechter Program director Dr. Melvin McInnis, began by analyzing deaths and related factors among 1,128 people who had volunteered for the program’s long-term study of people with and without bipolar disorder.
They found that all but 2 of the 56 deaths since the study began in 2006 were from the group of 847 people in the study who had bipolar disorder.
With statistical adjustments, their analysis shows that having a diagnosis of bipolar disorder made someone six times more likely to die over a 10-year period than people in the same study who did not have bipolar disorder.
In comparison, study participants who had ever smoked or were over 60 years old were more than twice as likely to die in the same period as people who never smoked or were under 60 years old, regardless of their bipolar status.
The researchers then turned to another data source to see if they could find the same effect.
They analyzed years of anonymized patient records for more than 18,000 people who receive primary care through Michigan Medicine, UM’s academic medical center.
Among this group, people with bipolar disorder were four times more likely to die during the study period than those without a history of bipolar disorder.
The team studied the records of more than 10,700 people with bipolar disorder and a comparison group of just over 7,800 people without any psychiatric disorder.
The only factor associated with an even higher chance of dying during the study period in this group of people was high blood pressure . Those with high blood pressure were five times more likely to die than those with normal blood pressure, regardless of whether they had bipolar disorder or not.
In contrast, smokers were twice as likely to die as non-smokers in this sample, and those over 60 years of age were three times as likely to die, both regardless of their bipolar status.
"To our great surprise, in both samples we found that having bipolar disorder poses a much higher risk of premature death than smoking ," said McInnis, a professor of psychiatry at the U-M School of Medicine.
He hopes the findings will prompt further action in the medical and public health communities to address the many factors that contribute to this extra high risk of death in people with bipolar disorder.
"Over the years, there have been all kinds of programs implemented for smoking prevention and cardiovascular disease awareness, but never a campaign on that scale for mental health," he said, noting that about 4% of Americans live with bipolar disorder, while about 11.5% of Americans smoke.
Other differences between groups
Yocum and McInnis note that people with bipolar disorder in both groups were much more likely to have ever smoked than people without bipolar disorder, which is consistent with previous studies.
Nearly half (47%) of UM patients with bipolar disorder had a history of smoking, as did 31% of Prechter’s participants with bipolar disorder.
In comparison, smoking among those without bipolar disorder was 29% of UM patients and 8% of Prechter participants.
People with bipolar disorder in both groups were also much more likely to be women, and female gender was associated with a slightly lower risk of premature death.
In Prechter’s cohort, people with bipolar disorder were much more likely to have asthma, diabetes, high blood pressure, migraines, fibromyalgia, and thyroid conditions than those who had not been diagnosed with bipolar disorder.
Within the group of participants in Prechter’s study who have bipolar disorder, being a smoker and scoring higher over time on a standardized survey of depression symptoms were associated with a double the risk of death, compared with participants who had bipolar disorder. but they did not smoke or score lower over time on depression ratings.
Interestingly, the researchers found no association between the risk of death and the number of years Prechter’s participants had been taking medication for mental health symptoms. There was also no association with anxiety and mania scores.
Only among people with bipolar disorder in the UM patient sample, high blood pressure was also associated with a five-fold increased risk of death, while smoking was associated with a nearly two-fold increased risk of death.
Information on depression scores or medication use over time was not available for this group.
A way forward
Both Yocum and McInnis say the findings, combined with studies on the health status, health risk behaviors and specific causes of death of people with bipolar disorder, could inform efforts to improve the health and quality of lives of people with this condition.
Previous research has shown that people with bipolar disorder are more likely to have metabolic syndrome, putting them at higher risk for diabetes and cardiovascular conditions due to a combination of factors related to waist size, cholesterol, blood sugar, blood and blood pressure. Medications for bipolar disorder may contribute to this.
Also important: the side effects of bipolar disorder symptoms. Lack of activity, poor diet, drug and alcohol abuse, and lower rates of education and employment also increase overall health risk, while health insurance coverage and access to care may be less consistent.
Researchers say educating more teens and adults about how to cope with stress, distress and mood fluctuations, and how to identify and get help for symptoms of depression, could be part of greater early intervention.
Bipolar disorder often begins to manifest as depression, and there are currently no good ways to predict which people will develop bipolar disorder, although a family history of the condition is known to increase the risk.
Genetic research at the Prechter Program and elsewhere is studying these contributing factors.
"Bipolar disorder will never be listed on the death certificate as the primary cause of death, but it can contribute immediately or secondarily to a death, including suicides," said Yocum, who notes that cross-sectional studies have found that, on average, People with bipolar disorder die 8 to 10 years earlier than other people their age .
Similarly, McInnis says, smoking is rarely listed on death certificates, but is known to be a major risk factor leading to cancers and cardiovascular emergencies that are listed as causes of death.
That is why it has received so much attention from agencies and organizations that carry out public health campaigns.
"We need to know more about why people with bipolar disorder have more illnesses and health behaviors that compromise their lives and life expectancy and do more as a society to help them live healthier and have consistent access to care," she said.
Reference : “Comparative mortality risks in two independent bipolar cohorts,” Psychiatry Research . DOI:10.1016/j.psychres.2023.115601
The study was funded by the Heinz C. Prechter Bipolar Research Fund of the Eisenberg Family Depression Center at the University of Michigan (link is external) and the Richard Tam Foundation, as well as the National Institute of Mental Health and the National Center for for Advancing Translational Sciences, both part of the National Institutes of Health (MH100404, MH106434, TR002240)
