The Effexor drug is a powerful treatment for depression. But, one of the major side effects is the increased thoughts of suicide, and the tendency to act upon those thoughts. Thus, it may seem to defeat its intended purpose. However, if you decide to take the prescription, you need to also understand that it can cause an irregular heartbeat, seizures and more. If you decide later that the drug is not for you, please get off of the drug slowly, under a doctor's supervision. Stopping cold turkey is risky and it is not recommended.