Targeted memory reactivation (TMR) therapy applied during rapid eye movement (REM) sleep modulates emotions in dreams and may be a complementary therapeutic approach for the treatment of nightmare disorder. These are the findings of a study published in the journal Current Biology.
Nightmares elicit strong negative emotions during REM sleep, often involving aggression, conflict, anger, fear, and sadness. Individuals who experience frequent nightmares that cause distress or impairment to social, occupational, or other types of functioning fit the criteria of nightmare disorder. The pathophysiology of nightmare disorder is largely unknown, and as such, few treatment options are available. The only robust treatment option is imagery rehearsal therapy (IRT).
In this study, adults (N=36) with nightmare disorder were recruited between 2020 and 2022 and randomly assigned to undergo TMR manipulation in addition to IRT to evaluate its potential effectiveness compared with IRT alone. During IRT sessions, a sound assoicated with a positive scenario in a dream was established. For patients in the TMR cohort (n=18), the positively associated sound was played during REM sleep over 14 nights and for control individuals (n=18), the same sound which had not been associated with a positive scenario was also played during REM sleep. The sounds were administered using a sleep headband equipped to play noises and automatically detect sleep stages.
These were the following characteristics of patients in the intervention and control cohorts, respectively:
- Mean age of 26.11±3.67 and 24.88±3.86 years
- 13 and 14 were women
- 2.94±1.73 and 2.58±1.19 nightmares a week
- Beck Depression Inventory (BDI) scores of 14.55±7.72 and 12.83±8.80 points
- Pittsburgh Sleep Quality Index (PSQI) scores of 7.77±2.86 and 7.55±3.22 points
- Nightmare Distress Questionnaire (NDQ) scores of 27.61±7.53 and 26.55±7.65 points
During the implementation of the study, the headbands of the 2 groups reported similar numbers of sound stimulations (d, 0.29; P =.38), sound intensities (d, 0.27; P =.37), REM arousal indices (d, 0.33; P =.31), REM durations (d, 0.24; P=.46), and days of stimulations (d, 0.10; P =.75).
For the outcome of number of nightmares per week, there were significant time (F[2,59.32], 60.11; P ≤.001) and group-by-time (F[2,59.34], 6.50; P =.003) effects observed, in which individuals in the TMR cohort reported fewer nightmares per week after the intervention (t[77.1], -2.34; P =.021) and at 3 months (t[86.3], -2.76; P =.007) compared with control individuals.
For the outcome of the joy content in dreams, there were significant time (F[1,34], 32.03; P ≤.001) and group-by-time (F[1,34], 16.95; P ≤.001) effects observed. Post-intervention, individuals who received TMR had more joy in dreams than control individuals (t[53,6], 3.26; P =.002) than they had at baseline (t[86.3], -6.91; P ≤.001).
A significant negative correlation between joy and fear in dreams was observed among those who received TMR but not among control individuals (P =.046). A linguistic analysis of dream diaries found similar findings, in which more positive emotions were observed in the dream descriptions post-intervention for those who received TMR compared with control individuals (P =.04).
This study may have been limited by not including a non-intervention control group.
These data indicated that TMR in addition to IRT may be an effective treatment strategy for nightmare disorders.
“… [W]e propose that TMR in REM sleep could be used as a new ‘sleep therapy’ in other psychiatric disorders with deficient extinction/emotion regulation as well (e.g., anxiety disorders, PTSD, mood disorders, and insomnia disorder),” the researchers concluded.
Schwartz S, Clerget A, Perogamvros L. Enhancing imagery rehearsal therapy for nightmares with targeted memory reactivation. Curr Biol. 2022;32(22):4808-4816.e4. doi:10.1016/j.cub.2022.09.032