Five years ago, I was at a memorial. Another suicide. Our third doctor in 18 months.

Everyone kept whispering, “Why?”

That was when I decided I had to find an answer.

So I started counting dead doctors. I left that memorial service with a list of 10. Today I have 757 suicides on my registry.

And I began writing and speaking about why doctors die by suicide and why it’s so often hushed up.

The response was huge: So many distressed doctors (and medical students) wrote and phoned me. Soon I was running a de facto international suicide hotline from my home. To date, I’ve spoken to thousands of suicidal doctors; published a book of their suicide letters; attended more funerals; interviewed hundreds of surviving physicians, families and friends.

I’ve spent nearly every waking moment over the past five years on a personal quest for the truth of “why.” Guilt, bullying, exhaustion are big factors.

Here are some of the things I’ve discovered while compiling my list and talking to so many people:

– High doctor suicide rates have been reported since 1858. Yet more than 150 years later, the root causes of these suicides remain unaddressed.

– Many doctors have lost a colleague to suicide. Some have lost up to eight during their career – with no opportunity to grieve.

– We lose way more men than women. For every female physician on my suicide registry, there are seven men. Suicide methods vary by region and gender. Women prefer to overdose and men choose firearms. Gunshot wounds prevail out West. Jumping is popular in New York City. In India, doctors have been found hanging from ceiling fans.

– Male anesthesiologists are at highest risk. My registry also shows that most of these doctors kill themselves by overdose. Many have been found dead in hospital call rooms where they are supposed to be resting between cases.

– Lots of doctors kill themselves in hospitals. They jump from hospital windows or rooftops. They shoot or stab themselves in hospital parking lots. They’re found hanging in hospital chapels. Physicians often choose to die in a place where they’ve been emotionally invested and wounded.

– “Happy” doctors also die by suicide. Many doctors who die by suicide appear as the happiest, most well-adjusted people on the outside.

– Family members of doctors who have killed themselves are also at high risk of suicide. Sometimes even by the same method. A year after a depressed Kaitlyn Elkins, a star third-year medical student, chose suicide by helium inhalation, her mother, Rhonda, died by the same method. At the mother’s funeral, her husband told me, “Medical school has killed half my family.”

– Suicidal doctors are rarely homicidal. On the list of suicides I’ve compiled, only 2 percent (15) also involved homicide. Seven of those homicides were by male physicians who killed a female spouse/girlfriend (all in health care – four nurses, a nursing student, a pharmacy tech and a dentist) before killing themselves.

Three male physicians murdered their young children before taking their own lives. Another strangled his disabled adult daughter before killing himself. Less than 1 percent of all doctor suicides involve homicide of their children.

– Patient deaths hurt doctors. A lot. Even when there’s no medical error, doctors may never forgive themselves for losing a patient. Suicide is the ultimate self-punishment. In several cases, the death of a patient seemed to be the key factor in pushing them over the edge.

– Malpractice suits can be devastating. Humans make mistakes. Yet when doctors make mistakes, they’re publicly shamed in court, on TV and in newspapers (that live online forever). Many continue to suffer the agony of harming someone else – unintentionally – for the rest of our lives.

– Academic distress kills medical students’ dreams. Failing medical-board exams and not getting a post-medical-school assignment in a speciality of choice has led to suicides.

– Assembly-line medicine kills doctors. Brilliant, compassionate people can’t care for complex patients in 15-minute slots. When punished or fired by administrators for “inefficiency” or “low productivity,” doctors may become suicidal. Pressure from insurance companies and government mandates crush these talented people who just want to help patients. Many doctors cite inhumane working conditions in their suicide notes.

– Bullying, hazing and sleep deprivation increase suicide risk. Medical training is rampant with deplorable conditions – such as working nonstop for 24 hours or more – that are not permitted in other industries. Physicians report hallucinations, life-threatening seizures, depression and suicide due to sleep deprivation. Fatigued doctors have felt responsible for harming patients. Resident physicians are now “capped” at 28-hour shifts and 80-hour workweeks.

If they “violate” work hours (by caring for patients), they can be forced to lie on their time cards or be written up as “inefficient” and sent to a psychiatrist for stimulant medications. Some doctors kill themselves for fear of harming a patient as a result of their extreme sleep deprivation.

– Blaming doctors increases suicides. Words such as “burnout” are often employed by medical institutions to shift blame to doctors for their emotional distress while deflecting attention from unsafe working conditions. When doctors are punished with a loss of residency positions or hospital privileges for occupationally-induced mental health conditions, they can become even more hopeless and desperate.

Like everyone else, doctors have personal problems. We get divorced, have custody battles, infidelity, disabled children, deaths in our families. Yet working 60 to 80 or more hours per week immersed in our patients’ pain means we often have no time to deal with our own. I’m always surprised by how often nonmedical people tell me they are shocked that doctors have the same mental-health issues and personal problems that everyone else has.

After collecting so many stories over the past five years I believe that ignoring doctor suicides just leads to more doctor suicides. Suicide is preventable, but we have to stop with the secrecy and face up to what it is about being a doctor that can be so emotionally difficult.

I am hopeful that the forthcoming documentary “Do No Harm,” by Emmy-winning filmmaker Robyn Symon will raise awareness on both points. In the meantime, medical institutions need to openly acknowledge the problem and make changes to support the mental health of doctors and medical students.

Healers, after all, also need healing.