Mental illnesses such as major depression touch millions of lives every year and can lead to catastrophic ends, as tallied in the growing loss of life from suicide seen in recent years in Minnesota.

Yet tools to objectively measure and diagnose mental illness remain elusive. The National Institute of Mental Health wrote last year that the outward manifestations of mental illnesses are probably “late signs” of changes in the brain that took hold much earlier, emphasizing the need for tools to detect problems sooner.

“The opportunity to identify individuals at highest risk early in the disease trajectory, and to intervene at the earliest possible time, promises to potentially prevent illness onset and minimize the overall burden of illness,” the NIMH wrote.

Medibio, an Australian company with U.S. headquarters in Minnesota, is working hard on a set of offerings that it says could finally offer an objective way to diagnose a range of mental-health problems without relying solely on subjective assessments by health care practitioners.

One of the key insights behind Medibio’s plan lies in the two-decade-old discovery that changes in a person’s heart rate during sleep and breathing can reveal mental-health imbalances in a predictable, reproduceable way. Researchers have found that certain changes are associated with underlying conditions like anxiety and depression.

“Twenty-plus years ago we didn’t have the devices and data-science capabilities that we have today. As the technology caught up ... it became more practical to run clinical studies and collect data and continue to refine the science,” said Medibio Chief Technology Officer Jeremy Schroetter.

Though counterintuitive, sleep is an ideal time to take biometric measurements of mental-health conditions, Schroetter said. That’s because there’s no “noise” from external stimuli during sleep, giving researchers a chance to observe the body’s nervous-system reactions isolated from real-time stressful events.

For example, normally a person’s heart rate slows during sleep. But in a person with depression, it gradually increases at night until it’s up near the normal daytime heart rate by sunrise, Schroetter said. In a person with anxiety, the sleeping heart rate doesn’t drop down like normal, but rather slowly declines along a predictable slope before dipping close to a normal sleeping heart rate later at night.

Medibio has a variety of commercial products in the works, which focus on the collection and analysis of physical data that can help detect the presence of mental-health problems.

The data are collected via regulated products like wearable electrocardiogram readers as well as nonregulated devices like Fitbits and Apple watches.

Medibio mobile apps manage connections to the wearable devices and subjective data sources like mood tracking and journaling, while Medibio’s cloud-computing platform uses “machine learning” to recognize indications of mental-health problems. So far a few employers have signed up to offer Medibio’s new corporate mental-health products to employees, while consumers can download apps for their own use.

The company intends to submit a “clinical decision support tool” to the U.S. Food and Drug Administration for approval later this year, following the conclusion of a clinical trial. It also plans to continue working with well-known names in medicine to publish peer-reviewed results of its research.

“Our goal has really been to commercialize this science into a portfolio of products that go from general mental wellness, if I can call it that, all the way up to mental illness,” Schroetter said.

Recent statistics on suicide show that more Americans are developing full-blown mental illness.

The Centers for Disease Control and Prevention reported June 7 that the rate of suicide in the United States has grown by 25 percent since 1999. In Minnesota, the suicide rate increased 40 percent between 1999 and 2016, one of the largest increases in the nation.

Although suicide is often associated with symptoms of mental illness, more than half of people who died by suicide in 2016 were not diagnosed with a mental illness, the CDC said. (People seeking immediate help can always call the National Suicide Prevention Lifeline, 800-273-8255.)

Medibio said its offerings are intended to “empower” patients by giving them access to their personal data and analysis, which can help them make better decisions and provide medical insights. The tools can be used to detect signs of disease and feedback about the drugs prescribed.

“We have employed data science and machine learning to analyze that heart-rate data and we have drawn correlations between ... the heart-rate data during sleep and a number of different conditions like anxiety, depression, psychotic depression, schizophrenia, PTSD,” Schroetter said.