During the past decade or two, investigators from various countries have been attempting determine whether levels of cholesterol in the blood have anything to do with depression and suicide. Some studies have said no, while others have said yes but diverge on whether low cholesterol or high cholesterol is the culprit.

Now comes still another investigation bolstering the high serum cholesterol-
depression-suicide connection. It is reported in the April American Journal of Psychiatry by Antti Tanskanen, M.D., of the department of psychiatry at Kuopio University Hospital, Kuopio, Finland, and his colleagues.

One reason past studies about this subject have conflicted, Tanskanen and his team conjectured, was that researchers invariably grouped all types of suicides in their analyses. Yet persons who commit suicide by violent means, such as guns and hanging, they reasoned, might well be more impulsive and aggressive than individuals who commit suicide by nonviolent means, such as taking a drug overdose. And because of these temperament differences, they speculated, persons who commit suicide by violent means might have very different levels of cholesterol from those who kill themselves by nonviolent means.

Thus, the researchers decided to see whether they could find a connection between serum cholesterol and suicide by analyzing the cholesterol levels of persons who had committed suicide by violent means separately from the levels of persons who had killed themselves by nonviolent means.

They chose as their subjects some 37,000 Finns whose cholesterol levels had been measured sometime between 1972 and 1992 and who had then been followed up some years later for their health outcome. Out of the 37,000 subjects, during the follow-up period 114 men and 16 women died by violent suicide, and 30 men and 16 women died by nonviolent suicide. The researchers then attempted to see whether there was any correlation between the cholesterol levels of the 130 who had died by violent suicide and whether there was any connection between the cholesterol levels of the 46 who had died by nonviolent suicide.

While the researchers found no link between cholesterol level and nonviolent suicides, they did find one between cholesterol level and violent suicides, and it was one of high serum cholesterol.

Certainly there is some rationale to this finding. For instance, as Neal Barnard, M.D., a psychiatrist, nutrition researcher, and president of the Physicians’ Committee for Responsible Medicine in Washington, D.C., told Psychiatric News, "We know that cholesterol is a precursor for testosterone, and testosterone is clearly linked to aggression, so that men who are, for whatever reason, imbued with higher serum concentrations of testosterone. . .might be at risk for more psychological difficulties—which we know is true. You have seen these articles of people shooting up steroids; they have all kinds of problems, including psychological problems. So we might assume that one of the things that this could be linked with is a variety of psychological sequelae, including suicide."

But studies like that conducted by the Finns are risky, Artemis Simopoulos, M.D., an endocrinologist and president of the Center for Genetics, Nutrition, and Health in Washington, D.C., cautioned in an interview. "Association studies are very difficult to interpret."

What is now needed to reinforce a link between high cholesterol and violent suicide is not just more research but studies other than association studies, said Simopoulos, Barnard, and Richard Stein, M.D., chief of cardiology at the Brooklyn (N.Y.) Hospital Center and an American Heart Association spokesperson.

For instance, Simopoulos would like to see a double-blind, controlled trial on patients who are properly selected and matched. Barnard would like to see a study that investigates whether high cholesterol predisposes individuals to violent suicide via certain hormonal paths. He visualizes such an investigation being conducted on persons who have attempted violent suicide but failed, or perhaps on persons jailed for violence.

"What we are starting to discover," Barnard explained, "is that high cholesterol doesn’t hurt just your heart. We now know that high cholesterol causes all kinds of problems, from heart disease to impotence. . . .So there is a whole web of changes that go together, and somehow the psychological piece of this is now entering into the research, and we are trying to sort it out."

Although Simopoulos’s personal interest lies more in nutrition and development than in cholesterol and suicide, she still considers this terrain "a very important area."