Mental Imagery and Targeted Memory Reactivation in Insomnia

Overview

In this clinical trial, the investigators test whether mental Imagery Rescripting (IR), a technique where the individual is instructed to transform a negative memory or image into a positive one, and olfactory Targeted Memory Reactivation (TMR), a technique used to strengthen memories, can reduce hyperarousal and insomnia severity in patients with Insomnia Disorder (ID). Patients with ID will be randomized into four groups: in the first group (SH group), patients will have 4 weekly sessions (1 session/week) of a minimal intervention for insomnia (sleep hygiene information) in the presence of an odorless diffuser, which will be also used during the night. In the second group (IR group), patients will use IR during wakefulness to induce a state of relaxation and positive emotionality. More specifically, during 4 weekly sessions of IR, patients will imagine a negative scenario related to their pre-sleep images or current concerns (e.g., social interactions, self-image, sleep problem, nightmares) and transform it into a positive script. They will then perform IR every day for 4 weeks at home in the presence of an odorless diffuser, which will be also used during the night. In the third group, patients will undergo the same 4 weekly IR sessions and an odor will be paired to the positive imagery and will be diffused during the night (TMR group). Patients from this group will also perform IR every day for 4 weeks at home. Finally, the fourth group (OA group) will receive 4 weekly sessions of sleep hygiene instructions in the presence of an odor, which will be also used during the night. Clinical evaluation of insomnia severity before and after the intervention will take place using the Insomnia Severity Index (ISI, primary outcome measure). At the end of these interventions, patients with persistent symptoms will benefit from an alternative experimental treatment ("rocking bed") in which they will be cradled for one night. The investigators hypothesize that patients treated with IR will have significantly reduced insomnia severity compared to participants who received a minimal intervention. They also hypothesize that patients of the TMR group, will have more reduced ID severity compared to participants performing IR and with an odorless diffuser, therefore without an association (IR group). Finally, they hypothesize that one night of sleeping in a rocking bed will improve objective measures of sleep in ID compared to a stationary condition.

Interventions

• Behavioral Imagery Rescripting (IR)
  Imagery rescripting (IR) is a technique where the individual is instructed to imagine a negative memory or image as vividly as possible, and to change it in a direction that he/she desires. IR seems particularly efficient because it is based on the experienced emotions during perceptual information processing, thereby eliciting stronger emotional responses than verbal processing.
• Behavioral Imagery Rescripting (IR) and Targeted Memory Reactivation (TMR) during sleep
  Targeted Memory Reactivation (TMR) is a technique used to strengthen a memory trace during sleep. TMR is used to modify memory formation through the application of cues during sleep. In this TMR protocol, an olfactory cue is associated with the imagery rescripting (IR) during the day, and then administered during sleep. In that way, the replay of the associated memory and its corresponding neural representation in memory networks are artificially promoted, a procedure which usually strengthens m
• Behavioral Sleep Hygiene
  Sleep hygiene education includes modifications in the behavior (e.g., exercise, coffee, alcohol intake) and environment (e.g., light, noise, temperature conditions) that offer to the individual the foundation for healthy sleep. Sleep hygiene is an important component in treating ID, but insufficient and less effective than CBT-I when offered alone.
• Behavioral Sleep Hygiene + Odor
  Sleep hygiene instructions will be applied in the presence of an odor, which will be also used during the night.
• Other "Rocking bed" if patients still have insomnia complaints (ISI >10) after the 4 weeks of the intervention
  Rocking stimulation boosts brain oscillations in deep sleep (i.e., sleep spindles and slow oscillations) into a rhythmic appearance supporting a neurophysiological mechanism whereby continuous rocking entrains endogenous thalamo-cortical sleep oscillations. The beneficial effects of rocking strengthening the continuity of sleep might have clinical applications and it will be of interest to evaluate if such non-pharmacological could improve sleep and reduce such features of hyperarousal in ID pat

Primary outcome measures

• Insomnia Severity Index (ISI) [Time frame: Baseline, 5 Weeks and 3 Months]

Secondary outcome measures (7)

• Pittsburgh sleep quality index (PSQI) [Time frame: Baseline, 5 Weeks and 3 Months]
• Total Sleep Time (TST) [Time frame: Baseline and 5 Weeks]
• Wake After Sleep Onset (WASO) [Time frame: Baseline and 5 Weeks]
• Beck Depression Inventory II (BDI-II) [Time frame: Baseline, 5 Weeks and 3 Months]
• State Trait Anxiety Inventory (STAI) [Time frame: Baseline, 5 Weeks and 3 Months]
• Sleep efficiency (SE) [Time frame: Baseline and 5 Weeks]
• Micro-arousals [Time frame: Baseline and 5 Weeks]

Eligibility criteria

Inclusion criteria

• Age between 18 and 45 years
• Insomnia disorder according to the International Classification of Diseases 3 (ICSD-3)
• ISI > 10
• PSQI > 5
• No other current treatment for Insomnia

Exclusion criteria

• patients with another psychiatric disorder requiring acute treatment according to DSM-5
• patients with medical (e.g. neurological disorders) or other disorders explaining the predominant complaint of insomnia (e.g., sleep apneas with ODI>15/h, restless legs syndrome, periodic limb movements with PLM>15, chronic pain)
• patients with significant substance use/withdrawal
• patients with heavy smoking
• known pregnancy
• patients suffering from anosmia, olfactory related issues and respiratory pathology

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Switzerland · 1 center

• Center for Sleep Medicine — Geneva

Identifiers

NCT: NCT06335784 · 2023-00456

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗