Longer duration of antidepressant treatment with selective serotonin reuptake inhibitors or tricyclic antidepressants was associated with an increased risk of sudden cardiac death in a Danish nationwide study.[1] Participants who took antidepressants for 1 to 5 years had a 56% higher risk of sudden cardiac death.[1] In the 30-39 age group, those who used antidepressants for 1 to 5 years were three times more likely to have sudden cardiac death than those who did not take the drugs.[1] When taking antidepressants for 6 years or more, this risk was five times higher.[1] Sudden cardiac death usually occurs within one hour of a sudden cardiac arrest that is not successfully treated, and accounts for approximately half of all deaths from cardiovascular disease.[1] The study confirmed previous hypotheses about an increased risk of sudden cardiac death with antidepressant use, with differences by age and length of treatment.[1]