Taking antidepressants may raise the risk of heart disease in men. They can thicken artery walls through an as yet unknown mechanism.
The drugs seem to accelerate atherosclerosis by increasing the thickness of the "intima media", the inner and middle layers of the arteries. They particularly affect the carotid arteries that feed blood to your brain.
According to the Los Angeles Times:
"... [T]he intima-media thickness of men taking antidepressants was 37 microns (about 5 percent) thicker than that of men not taking the drugs. When the team looked at 59 twin pairs in which one twin was taking the drugs and the second was not, the artery was 41 microns thicker in the twin taking the drugs."