After Searching 12 Years for Bipolar Disorder’s Cause, a Team Concludes It Has Many

A long-term study in more than 1,100 people yields a new seven-factor framework that could help patients, clinicians and researchers.

7:00 AM

Author | Kara Gavin

Nearly 6 million Americans have bipolar disorder, and most have probably wondered why. After more than a decade of studying over 1,100 of them in-depth, a University of Michigan team has an answer — or rather, seven answers.

MORE FROM THE LAB: Subscribe to our weekly newsletter

In fact, the team says, no one genetic change, chemical imbalance or life event lies at the heart of every case of the mental health condition once known as manic depression.

Rather, every patient's experience with bipolar disorder varies from that of others with the condition. But all of their experiences include features that fall into seven classes of phenotypes, or characteristics that can be observed, the team reports in a new paper in the International Journal of Epidemiology.

The team, from U-M's Heinz C. Prechter Bipolar Research Program, collected and analyzed tens of thousands of data points over years about the genetics, emotions, life experiences, medical histories, motivations, diets, temperaments and sleep and thought patterns of research volunteers. More than 730 had bipolar disorder, and 277 didn't. Three-quarters were active research participants in the Longitudinal Study of Bipolar Disorder.

Using those findings, the team developed a framework that could be useful to researchers studying the condition, clinical teams treating it and patients experiencing it. The team hopes it will give them all a common structure to use during studies, treatment decisions and more.

"There are many routes to this disease and many routes through it," says Melvin McInnis, M.D., lead author of the paper and head of the program based at the U-M Depression Center. "We have found that there are many biological mechanisms that drive the disease and many interactive external influences on it. All of these elements combine to affect the disease as patients experience it."

The Prechter program is named for a Detroit automotive pioneer who fought bipolar disorder even as he built a successful business.

Long-term funding from this program has made it possible to build a massive library of data from the Prechter cohort of patients, which is two-thirds female and 79 percent white with an average age at enrollment in the study of 38 years. On average, participants had their first depressive or manic episode at age 17. Many had other mental health conditions.

There are many routes to this disease and many routes through it.
Melvin McInnis, M.D.

Seven classes and the key findings that shaped them

The seven phenoclasses, as the U-M team has dubbed them, include standard measures doctors already use to diagnose and track the progress of bipolar disorder.

SEE ALSO: How Research Brightens the Bipolar Disorder Outlook

In addition, they include:

  • Changes in cognition, which includes thinking, reasoning and emotion processing

  • Psychological dimensions such as personality and temperament

  • Measures of behaviors related to substance use or abuse — called motivated behaviors

  • Aspects of the person's life involving family, intimate relationships and traumas

  • Patterns of sleep and circadian rhythms

  • Measures of how patients' symptoms change over time and respond to treatment

Some of the key findings the U-M team made in the Prechter cohort include:

Although bipolar disorder tends to run in families, the long-term study revealed no one gene explains it, says McInnis, who is the Woodworth Professor of Bipolar Disorder and Depression in the U-M Medical School's Department of Psychiatry.

"If there was a gene with a strong effect like what we see in breast cancer, for instance, we would have found it," he explains. "We hope this new framework will provide a new approach to understand this disorder, and other complex diseases, by developing models that can guide a management strategy for clinicians and patients and give researchers consistent variables to measure and assess."

He adds, "Bipolar disorder has a lot to teach humankind about other illnesses because it covers the breadths of human mood, emotion and behavior like no other condition. What we can learn in bipolar about all these factors will be directly applicable to monitoring other disorders and personalizing the approach to managing them."

The Prechter Bipolar Research Program is still recruiting participants for its long-term study and accepting donations from those who want to help the research move forward. More information is available at PrechterProgram.org.


More Articles About: Body Work bipolar disorder Mental Illness Mental Health
Health Lab word mark overlaying blue cells
Health Lab

Explore a variety of healthcare news & stories by visiting the Health Lab home page for more articles.

Media Contact Public Relations

Department of Communication at Michigan Medicine

[email protected]

734-764-2220

Stay Informed

Want top health & research news weekly? Sign up for Health Lab’s newsletters today!

Subscribe
Featured News & Stories Breaking Down Mental Health on blue background and text inside a yellow head graphic
Breaking Down Mental Health
Depression and Sleep
In this episode, learn to understand the interplay between depression and how cognitive behavioral therapy can improve sleep.
Breaking Down Mental Health on blue background and text inside a yellow head graphic
Breaking Down Mental Health
Pediatric Depression
In this episode, learn to differentiate between depression presentation in children versus adults and determine appropriate screening tools for depression for the screening of children and adolescents.
Breaking Down Mental Health on blue background and text inside a yellow head graphic
Breaking Down Mental Health
Psychotropic Medications for Depression
In this episode, learn to identify appropriate selective serotonin reuptake inhibitors for the management of depression in pediatric patients and how they work and identify appropriate serotonin-norepinephrine reuptake inhibitors for the management of depression in pediatric patients and how they work.
Minding Memory with a microphone and a shadow of a microphone on a blue background
Minding Memory
The Professional Workforce of People Who Provide Dementia Care
In this episode of Minding Memory, Matt & Donovan speak with Dr. Joanne Spetz, the Brenda and Jeffrey L. Kang Presidential Chair in Healthcare Finance and Director of the Philip R. Lee Institute for Health Policy Studies at the University of California, San Francisco (UCSF). Joanne talks with Matt & Donovan about who makes up the professional workforce of people who provide dementia care and how these individuals play a critical role in the delivery of services. Joanne also discusses how different professional roles interact across setting of care. Lastly, Joanne introduces a new study she is working on with Donovan called the National Dementia Workforce Study (NDWS) that will be surveying a large group of clinicians who provide care for people living with dementia.
Woman sleeping on a couch holds her stomach, as if in pain
Health Lab
Long COVID-19 is linked to chronic pain conditions
Therapies for pain conditions like fibromyalgia provide clues for helping those with long COVID-19
Dark staircase leading to blue sky above
Health Lab
Ketamine’s promise for severe depression grows, but major questions remain
New findings about the impact of IV ketamine on treatment resistant depression add more fuel to the potential for broader use and insurance coverage.