Most antidepressants do not directly affect Deep sleep staging, except for some MAOIs (monoamine oxidase inhibitors) that are only prescribed for cases in which the more current medications are not responsive.
That said, antidepressants can impact one’s sleep in other ways. For example, the very common class of antidepressants known as SSRIs (selective-serotonin-reuptake-inhibitors) can drastically reduce the time spent in REM sleep. Many people on SSRIs in fact lose much of their dream recall due to this effect, while at the same time report more intensely negative and bizarre dreams when they can recall them.
Keep in mind, that while the value of Deep sleep is its association with brain restoration, it’s not know exactly what is the role of Deep sleep for the body.For instance, there’s some evidence that Deep sleep is involved in the regulation of metabolism, as people who are selectively deprived of Deep sleep have an increased risk for diabetes.
However, getting more deep sleep isn’t always the best. In fact, decreasing slow wave sleep in those with depression can alleviate symptoms. Elevated levels of slow wave sleep are also common in those suffering from chronic fatigue syndrome. Finally, increased levels of deep sleep are associated with antisocial behavior, specifically severe aggression.
Sleep is really holistic and all sleep phases are important for good health. So the best baseline for evaluating sleep health remains your own sense of wellbeing throughout the day. From this starting point, you can monitor the conditions that provide for –or disrupt—your individual sleep style.