A neuron, connected to many others. Flickr/ZEISS Microscopy If you don't understand a problem, chances are you won't be able to solve it.

That's a major stumbling block for scientists attempting to develop treatments for brain disorders such as autism, depression, dementia, and more that will affect an estimated 100 million Americans at some point in their lives.

But cutting-edge scientific research is "providing a new view of brain function in health and disease" that could eventually yield treatments for many brain disorders, writes Cornelia Bargmann, a neurobiologist at the Howard Hughes Medical Institute at the Rockefeller University.

As we learn more about how the brain works and what happens when disorders strike, what we learn could help us figure out how to treat diseases that we haven't even understood before. In her article in a recent issue of The Journal of the American Medical Association, Bargmann identifies four areas in particular where recent advances and continued research could lead to unprecedented treatments.

Deep brain stimulation

Through much research, scientists have come to understand the brain as many circuits of connected cells that communicate with each other through a combination of electrical and chemical signals. Simply put, brain disorders interfere with this complex system of communication.

One way to treat brain disorders would be to restore normal communication, and doctors are already doing this to some degree with a therapy for Parkinson's disease called deep brain stimulation.

More or less, the brain has two competing circuits for controlling movement, one that encourages movement and one that discourages it. Parkinson's disease kills a group of brain cells involved in one circuit, which knocks them both out of balance and causes the involuntary movement problems the disease is known for. Deep brain stimulation delivers small electric shocks to a different group of brain cells and changes their behavior to rebalance the whole movement control system, substantially reducing movement problems for people with Parkinson's.

If we're able to understand how more circuits in the brain work (like those that control pain, emotions, and arousal), we could potentially use deep brain stimulation to rebalance them when diseases such as depression, obsessive-compulsive disorder, and epilepsy throw them off. Even memory loss potentially could be treated by rerouting traffic in the brain to restore balance, Bargmann writes. In about five years, it's possible we might see deep brain stimulation starting to help some people with one or two of these conditions, she said.

We still have a lot to learn about how a healthy brain works. Getty Images/Matt Cardy

Functional imaging

Doctors can watch the circuits of a patient's brain at work via functional magnetic resonance imaging (fMRI), which captures changes in blood flow in the brain and indicates which parts of a patient's brain are active. This is helpful when a brain disorder doesn't change the way circuits in the brain look (like Parkinson's does by killing cells), but rather how they work.

Especially for psychiatric disorders, Bargmann writes, being able to see exactly how a patient's brain is working differently than the wide range of normal function could help doctors choose the best treatment for them. Research has already indicated that differences in brain function may predict which treatment is more likely to work for a person with depression, though the results are preliminary.

Repairing damaged cells

Brain cells are ground zero for brain disorders. Wikimedia Commons All the circuits we've been talking about are made up of individual cells that have to be healthy for the brain to function properly.

Diseases that kill specific types of brain cells, like Parkinson's and Lou Gehrig's, could be treated at their source if we could replace the cells they've damaged with new ones.

The past decade of research on stem cells means scientists are now able to turn induced pluripotent stem cells, which are made from normal body cells and can become many different types of cells, into the specific brain cells Parkinson's and Lou Gehrig's diseases damage. According to Bargmann, the first clinical trials transplanting these cells into patients are being planned.

Besides stem cells, scientists are looking into ways to regenerate injured nerve cells by stimulating repair and regrowth tools the body has but doesn't use in the brain, Bargmann writes. Continuing research into how to repair the brain's cells, not just work around the damaged ones, could yield treatments for these previously untreatable diseases — but this is still far away.

Using genetic clues

Finally, Bargmann writes that understanding how genes are related to brain disorders could be helpful in developing treatments.

Not all brain disorders are caused by genetic mutations (that we know of), and even knowing a genetic mutation is associated with a disease does not yet mean we necessarily know how to treat it. But knowing what mutations are linked to a disease can help scientists figure out what exactly goes wrong to cause the disease's symptoms, and what might be promising areas of research to focus on to come up with a treatment.

For example, Bargmann notes that several gene mutations linked to schizophrenia (which, like many brain disorders that affect adults, is likely caused by both genetic and environmental factors) happen to be in genes that are used to make a certain part of brain cells. That information means scientists can double down on efforts to test treatments targeting those specific parts of affected cells.

While this new genetic research suggests promising new directions, it's not a given these efforts will be fruitful.

What the future holds

A test subject wears a cap that measures brain activity. Michaela Rehle/Reuters The research progress Bargmann describes in deep brain stimulation and regenerating neurons could eventually yield effective treatments for brain disorders by fixing what goes wrong with the brain's hardware.

And the advances in imaging and genetics could finally bring precision medicine to psychiatry, Dr. Charles Nemeroff, the Chairman of Psychiatry and Behavioral Sciences at the University of Miami Miller School of Medicine, told Tech Insider.

"We're unable at the current time to predict with any reasonable degree of certainty within a particular diagnosis what's the best of the available treatments for a given patient," he said.

That's a huge problem, because it means doctors have to find the treatment that works best for a patient through trial and error, and it can take a while to find the right one.

In as little as 10 years, Nemeroff suggested, doctors may be able to look at a patient's genes and fMRI scan results and use that information to predict with greater certainty what treatment will work for that particular patient.

Tools that help doctors prescribe existing treatments more effectively and help scientists develop potential new treatments could help us treat diseases we hardly understand right now.

This vision of the future can't come soon enough. As Bargmann told Tech Insider, "there are too many people who are suffering too much that we can do too little for."