Mirtazapine and sleep

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By Dr Simon Kyle

Mirtazapine is an antidepressant drug prescribed to treat Major Depressive Disorder, Obsessive Compulsive Disorder and a range of anxiety disorders. Alongside these, it may be prescribed ‘off-label’ to people experiencing prolonged periods of poor sleep.

Does mirtazapine help you sleep?
Research has shown that Mirtazapine, taken at bedtime, to have a positive impact on insomnia symptoms in people with clinical depression. It has also been shown to improve the percentage of time in bed spent asleep, decrease nighttime awakenings and increase total time spent asleep (Winokur et al., 2000, Schittecatte et al., 2003).

Taking mirtazapine for sleep
People with depression are often seen to experience increased REM sleep density and reduced latency to REM sleep. This, in turn, reduces the amount of time spent in the stages of slow-wave sleep, impacting negatively on sleep quality. The majority of antidepressants therefore, work to suppress REM sleep, and normalize these sleep parameters.

Mirtazapine however, is one in a line of antidepressant drugs that only modestly suppress REM sleep (Aslan et al., 2002) whilst still having a beneficial impact on sleep continuity and duration due to its anti-histaminergic effects. This has led to the drug being prescribed to people who do not suffer from depression but do have insomnia.

Mirtazapine’s sedative effects may help lessen the hyperarousal which prevents people getting to sleep, whilst increasing the stages of slow-wave, restorative sleep (Aslan et al., 2002).

Side effects of Mirtazapine
As with all antidepressants, there are certain side effects associated with Mirtazapine use. These include weight gain and, because the drug remains in one’s system throughout the course of the day, a person might also experience drowsiness.

Less common side-effects include producing or exacerbating periodic leg movements in young healthy men which may affect their sleep quality, although this side-effect has only been reported in a recent, small-sample study (Fulda et al., 2013).

Unfortunately, one known symptom of Mirtazapine withdrawal is insomnia. So, whilst Mirtazapine may help you sleep when you are taking it regularly, changing the dose or stopping the medication altogether may again have a negative effect on your sleep.

You should always consult your doctor for advice on medication – starting, changing or finishing a course of medication can have serious effects. Ensure that you consult your GP if you have any questions on this.

Aslan, S., Isik, E., Cosar, B. (2002). The effects of mirtazapine on sleep: a placebo controlled, double-blind study in young healthy volunteers. Sleep, 25(6), 666-668.
Fulda, S., Kloiber, S., Dose, T., Lucae, S., Holsboer, F., Schaaf, L., Hennings, J. (2013). Mirtazapine provokes periodic leg movements during sleep in young healthy men. Sleep, 36(5), 661-669.
Winokur, A., Sateia, M.J., Hayes, J.B., Bayles-Dazet, W., MacDonald, M.M., Gary, K.A. (2000). Acute effects of mirtazapine on sleep continuity and sleep architecture in depressed patients: a pilot study. Biological Psychiatry, 48(1), 75-78.
Schittecatte, M., Dumont, F., Machowski, R., Cornil, C., Lavergne, F., Wilmotte, J. (2003). Effects of mirtazapine on sleep polygraphic variables in major depression. Neuropsychobiology, 46(4), 197-201.

Filed under: Sleep aids