Those who have most severe mental health problems, such as schizophrenia, are at greatest risk.
Although it's unclear how mental problems affect heart disease risks, researchers think stress may play a part.
The findings were published Sept. 24 in the journal Circulation: Cardiovascular Quality and Outcomes.
"The bottom line is that when considering a veteran's health care needs, mental health status, especially for more severe mental illnesses, should be taken into consideration when calculating cardiovascular disease risk and considering the appropriate treatment options," study lead author Dr. Mary Vance said in a journal news release.
She's an assistant professor of psychiatry at the Uniformed Services University School of Medicine in Bethesda, Md.
For the study, Vance and her team collected data on more than 1.6 million vets. Among the participants, 45% of the men and 63% of the women were diagnosed with a mental health disorder. They ranged in age from 45 to 80.
After accounting for factors such as age, blood pressure, cholesterol and psychiatric medications, the researchers found that veterans with mental health conditions other than post-traumatic stress disorder (PTSD) had a higher risk for heart attack, stroke and death over five years.
For both men and women, psychosis (characterized by a disconnection from reality and can include schizophrenia) was linked to the strongest risk of heart troubles.
Among men, depression, anxiety, psychosis and bipolar disorder were linked with a greater risk of death due to heart disease.
Depression, psychosis and bipolar disorder were associated with increased odds for heart attack and stroke.
Among women, depression, psychosis and bipolar disorder increased heart disease risk, while psychosis and bipolar disorder boosted the odds of dying from heart disease.
PTSD among men was linked to a lower risk of heart disease, contrary to previous research.
The researchers said the findings might help doctors assess a patient's heart disease risk and determine who might benefit from cholesterol-lowering medications and blood pressure treatment.