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.
Most people have heard the "chemical imbalance" theory and believe it is true. It is important to realize that there is no scientific evidence for this theory. There is no credible scientific lab test showing the presence or absence of mental disease.
There is simply no way you can measure this imbalance.
It sounds scientific, but the drug companies merely use the chemical imbalance theory as a useful metaphor that justifies their aggressive use of antidepressants to correct this alleged "imbalance."
If you carefully study the history of psychiatry you will find that a biological explanation had to be found to justify the failing image of psychiatrists as respected scientific professionals.