Effects of Serotonin Reuptake Inhibitors on Heart Rate Variability: Methodological Issues, Medical Comorbidity, and Clinical Relevance


We were most interested to read the recent report by Licht et al. (1) on the impact of a variety of antidepressants on heart rate variability (HRV), a robust predictor of sudden cardiac death and future mortality. Longitudinal evidence was reported for the effects of antidepressants including tricyclics (TCAs), serotonergic and noradrenaline reuptake inhibitors (SNRIs), and serotonergic reuptake inhibitors (SSRIs) on HRV. New users of TCAs (n = 12) displayed a decrease in respiratory sinus arrhythmia (RSA) (an indicator of HRV that controls for respiration rate) of 23 msec over the 2-year assessment period; new users of SNRIs (n = 23) displayed a decrease of 12 msec; and new users of SSRIs (n = 74) displayed a decrease of 7 msec, compared with persistent non-users of medication.

Biological Psychiatry