Use of SSRIs and SNRIs, but not TCAs, is associated with increased REM sleep without atonia in a population with suspected parasomnia, with the highest estimates observed with SSRI+SNRI combination therapy.
Key Findings
Results
SSRI monotherapy was associated with a statistically significant increase in REM sleep without atonia compared to medication-free patients.
Patients on SSRI monotherapy had a 3.39% increase in RSWA% compared to those medication-free (p < 0.009).
RSWA scoring was based on submentalis and flexor digitorum superficialis (FDS) EMG using AASM criteria.
Analysis used linear regression adjusting for age, body mass index, gender, and race.
The overall sample included 1474 vPSGs, with 624 (42.3%) patients taking antidepressants and 850 (57.7%) non-users.
Results
SNRI monotherapy was associated with a larger increase in REM sleep without atonia than SSRI monotherapy compared to medication-free patients.
Patients on SNRI monotherapy had a 6.66% increase in RSWA% compared to those medication-free (p < 0.001).
This effect was nearly double the 3.39% increase seen with SSRI monotherapy.
Results were adjusted for age, BMI, gender, and race.
Overall mean RSWA% in the full sample was 11.9 ± 17.8.
Results
TCA monotherapy was not associated with an increase in REM sleep without atonia compared to medication-free patients.
Unlike SSRIs and SNRIs, TCA monotherapy did not result in a statistically significant increase in RSWA%.
This differential effect distinguishes TCAs from the other antidepressant classes studied.
The finding held across both monotherapy and combination therapy (SSRI+TCA and SNRI+TCA) analyses.
The combination of SSRI+TCA or SNRI+TCA also did not show increased RSWA%.
Results
Combined SSRI and SNRI therapy was associated with the highest estimated increase in RSWA% among all treatment groups, though the finding did not reach statistical significance.
Patients on both SSRI and SNRI had a 10.44% increase in RSWA% compared to medication-free patients (p = 0.089).
The authors note that 'combination subgroup findings should be interpreted cautiously given small sample sizes.'
This was the largest point estimate of RSWA% increase observed across all monotherapy and combination groups.
The lack of statistical significance may reflect limited power due to small subgroup sample sizes.
Methods
This study represents the largest analysis to quantify RSWA percentage and identify differential impacts of antidepressant class and therapy type on RSWA.
A total of 1474 video polysomnographies (vPSGs) scored for possible REM sleep behavior disorder (RBD) were analyzed.
Mean age of the sample was 53 ± 16.4 years, 53.1% male, and 73.1% White.
The study compared medication-free patients against those on SSRI, SNRI, TCA monotherapy, and various combination therapies.
The authors note findings 'should be interpreted within the context of the clinical criteria used for RSWA scoring.'
Methods
The study population consisted of patients referred for video polysomnography due to suspected parasomnia, with nearly half taking antidepressants.
624 of 1474 patients (42.3%) were taking antidepressants at the time of their vPSG.
850 patients (57.7%) were antidepressant non-users.
All vPSGs were scored for possible REM sleep behavior disorder (RBD).
RSWA was quantified using both chin (submentalis) and upper extremity (flexor digitorum superficialis) EMG channels per AASM criteria.
What This Means
This research suggests that not all antidepressant medications affect sleep in the same way. Specifically, two common classes of antidepressants — SSRIs (like fluoxetine or sertraline) and SNRIs (like venlafaxine or duloxetine) — are associated with increased muscle activity during REM sleep, a phenomenon called REM sleep without atonia (RSWA). Normally during REM (dreaming) sleep, the body is essentially paralyzed to prevent people from acting out their dreams. When this muscle suppression is incomplete, it can be a sign of or contribute to REM sleep behavior disorder (RBD), a condition where people physically act out their dreams. The study found that SNRIs had a larger effect on this abnormal muscle activity than SSRIs, and that taking both together was associated with the highest levels of abnormal muscle activity observed.
In contrast, an older class of antidepressants called tricyclic antidepressants (TCAs) did not show this same effect. Interestingly, when a TCA was combined with an SSRI or SNRI, the increase in abnormal muscle activity seen with the newer drugs alone was no longer observed, suggesting TCAs may counteract this effect. The study analyzed nearly 1,500 sleep studies from patients referred because of suspected sleep-related movement behaviors, making it the largest study of its kind to compare these medication classes.
This research matters because many people take antidepressants long-term, and these medications may influence the results of sleep studies used to diagnose RBD — a condition that can be an early warning sign of certain neurological diseases like Parkinson's disease. Clinicians interpreting sleep studies in patients on antidepressants may need to account for the type of antidepressant being taken, as it can affect how much abnormal muscle activity appears during REM sleep. The authors caution that findings from combination therapy groups should be interpreted carefully due to small numbers of patients in those subgroups.
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Ahdab J, Rodriguez C, Grigg-Damberger M, Araujo M, Andrews N, Thanaviratananich S, et al.. (2026). Antidepressant medications have differential effects on REM sleep without atonia quantified by chin and upper extremity EMG.. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine. https://doi.org/10.1007/s44470-026-00127-2