There are several truths about mental disorders. The first is that they are associated with higher levels of disability than nearly all other medical disorders. Unlike most forms of heart disease and cancer, mental disorders often begin before age 30 and interrupt early careers. They are the chronic, disabling disorders of young people, and they’re too often fatal. Suicide, nearly always associated with a mental disorder, kills more people than breast cancer or AIDS. There are more than 40,000 suicides a year in this country—more than twice the number of homicides.

Another truth is that disorders like depression, anorexia nervosa, and schizophrenia have mystified clinicians for centuries and remain no less mysterious today. Even our current tools for monitoring or manipulating the human brain are simply not up to the task of reading the language of the brain at the speed of thought. (However, we are getting better tools at an astonishing rate, thanks to the combined efforts of neuroscientists, engineers, computer scientists, and materials scientists in projects like the BRAIN Initiative—an effort to greatly improve our understanding of the brain.)

Our approach to treating mental disorders has changed radically over the decades. Once seen as psychic conflicts requiring psychoanalysis, they were later seen as chemical imbalances requiring medication. More recently, we’ve seen them as the result of abnormal electrical activity in specific circuits of the brain, analogous to an arrhythmia in the heart. Devices that deliver deep brain stimulation or transcranial magnetic stimulation are used to modulate this arrhythmia (see “A Shocking Way to Fix the Brain”).

Another truth: psychotherapy, meds, and devices all work to one degree or another, but not everyone responds to all of these approaches, and some respond to none. We still don’t know how to identify the best treatment for any individual. Some people with depression respond to cognitive behavior therapy, some to antidepressant medication, and some to deep brain stimulation. Some respond best to a combination of the three.

The inconvenient question might be, why are so few people in treatment? Fewer than half the people with a serious mental disorder like depression get treated. About half of those who receive treatment will get adequate or evidence-based care. And with our current options, only about half of those who get such care will recover completely. This means that only about 12.5 percent of people with a serious disorder are recovering.

Yes, we need better treatments based on modern science. But if we could improve access to today’s treatments and deliver high-quality care, that would go a long way toward reducing the disabling effects of these disorders.

Thomas Insel, head of the National Institute of Mental Health since 2002, announced recently that he’s leaving NIMH to join Google Life Sciences, part of the new conglomerate Alphabet.