Slow Wave Induction by Propofol to Eliminate Depression (SWIPED) I

Treatment-resistant depression (TRD) in older adults is a leading cause of disability, excess mortality from suicide, and dementia. Cognitive problems and sleep disturbances are common, contributing to recurrence and poor long-term outcomes. Disrupted slow wave sleep is at the nexus of depression and cognitive dysfunction in older adults. Novel approaches to target this core pathophysiology are lacking. Our mechanistic project is designed to elucidate the relationships between TRD and sleep disturbances in older adults. Through personalized infusions targeting electroencephalographic (EEG) patterns, we aim for a systematic characterization of the relationships between the propofol-induced EEG slow waves and enhancement of slow wave sleep. Through the repurposing of propofol as a therapeutic probe, this innovative proposal will establish whether EEG slow waves are a viable therapeutic target for novel antidepressant approaches.

Study Intervention

Propofol will be infused through a peripheral IV, with the assistance of target-controlled infusion software and pumps, with an anticipated infusion duration of 1-2 hours. Concurrent high-density EEG will be acquired, but with an updated recording rig and sensor nets that use either Elefix conductive gel or salt solution. An Axis P3364LV network camera, synchronized to EEG recordings, will provide video for post-hoc analysis. Participants will be discharged home after nurse monitoring and fulfillment of post-anesthetic care unit criteria.

Patients will be instructed by staff on operation of the Dreem headband for at-home overnight sleep EEG recordings. Patients will demonstrate ability to successfully wear the Dreem and initiate recordings without assistance. The device, charger, instruction sheet, and a link to a 2-minute instructional video will be provided to patients. This paradigm has been successful in the acquisition of preoperative sleep recordings in over 150 geriatric cardiac surgical patients and eight patients who underwent ECT for TRD (ClinicalTrials.gov NCT04451135).

Dreem recordings will be obtained prior to the first propofol infusion and on evenings of propofol infusions. Additionally, recordings will be obtained for up to 6 nights within a 2-week period after the final infusion, to evaluate persistence of restoration of sleep architecture. Participants will exchange the device with staff during each in-person visit, to allow device examination and data download.

Planned subgroup analyses include stratification by sex and age. For the purposes of Phase II of the study, additional subgroup analyses will be performed based on baseline sleep structure (e.g. total sleep time and proportion of time in N3 sleep), and time interval separating the two infusions.

• Propofol (Drug), also known as anesthetic: Targeted propofol infusion in TRD patients will induce sedation with maximal expression of EEG slow waves and minimal burst suppression.
• Electroencephalography (EEG) (Diagnostic test): EEG will be recorded during propofol infusion and during overnight sleep. Sleep EEG data will be acquired for a minimum of one night prior to the first sedation session, providing a baseline measure. Additional overnight sleep recordings will be performed on day of sedation and subsequent nights.
• Slow-Wave Activity (Diagnostic test): Duration of slow waves during sedation will be evaluated using automated approaches. SWA during sedation will be calculated as the total power in the 0.5-4 Hz frequency band/total time in minutes. SWA during N2/N3 sleep will be calculated as the total power in the 0.5-4 Hz frequency band/total time in minutes in the N2 and N3 sleep stages. Delta sleep ratio will be computed from the SWA measured during the first and second N2/N3 cycles.

Primary outcomes

• Number of Participants Without Serious Adverse Events During Propofol Infusions [Up to one week after propofol infusions]: Adverse events and serious adverse events, including incidence, severity, and likelihood of relation to intervention. Evaluate whether serial propofol infusions are safe (<5% serious adverse events directly attributable to infusions)
• Change in SWA During Propofol Infusions Compared to Awake Baseline Before Infusion [During two-hour propofol infusion]: Evaluate in geriatric TRD patients that propofol infusions can efficiently induce EEG slow waves during infusion. Sedation slow wave activity (SWA, frontal EEG power within 0.5-4 Hz frequency band) during propofol sedation compared to frontal EEG SWA during awake eyes closed baseline preceding infusion start. This is an indication of power/density of slow waves induced by propofol. Difference in 0.5-4Hz power (infusion - pre-infusion eyes closed). EEG power estimated using multitaper spectral analysis (Chronux toolbox). Difference values are averaged across the two infusions, leading to one outcome measure per participant.
• Proportion of Infusion Completers With Augmentation of Sleep SWA After Propofol Infusion [Over three-week period of pre- and post-infusion sleep recordings]: Evaluate Change in sleep slow wave activity during N2/N3 Sleep (post-infusion - pre-infusion). Pre-infusion measure of sleep slow wave activity is averaged across multiple recordings. Post-infusion measures are based on average of sleep slow activity from nights of morning propofol infusions. Evaluate whether propofol can augment total sleep SWA in greater or equal to 40% of study completers.

Secondary outcomes

• Effects on Suicidality [Baseline, 1-week Post 2nd-Infusion, 3-week Post 2nd-Infusion, 10-week Post 2nd-Infusion]: Evaluate whether propofol infusions are associated with suicidality. Suicidality assessed using Columbia Suicide Severity Rating Scale (C-SSRS). The scale for the CSSR-S is as follows: 0-No or Low Risk: No suicidal ideation or behaviors reported, 1-Moderate Risk: Suicidal thoughts with some intent or planning but no action taken, 2-High Risk: Suicidal ideation with intent, plan, or recent suicidal behaviors. C-SSRS was administered approximately 1 week before the first infusion (baseline), and then approximately 1, 3, and 10 weeks after the second infusion. No C-SSRS was obtained during the 2-6 days separating the first and second infusions.
• Changes in N3 Duration, REM Duration, Total Sleep Time (Post-infusion Change Relative to Baseline) [1 week before 1st infusion and recordings taken on both infusion nights]: Baseline measures are averages taken from 2-3 recordings before infusions. Averages for post-infusion are taken for measures derived on recordings on the evenings of morning propofol infusions. Reported difference is calculated from averages of measures from post-infusion recordings and averages of baseline recordings.
• Change in Delta Sleep Ratio (Infusion Nights - Baseline) [One week before first infusion and on nights after morning infusions]: Delta sleep ratio (DSR, calculated as the SWA of the 1st NREM cycle divided by the SWA of the 2nd NREM cycle, is unitless). Baseline measures are averages taken from 2-3 recordings during the week before infusions. Averages for infusion nights are taken for measures derived on recordings taken on the evenings of morning propofol infusions. Reported change is the difference (average of infusion nights - baseline average)
• Changes in Proportion of Total Sleep Time in N3, Proportion of Total Sleep Time in REM [Baseline pre-infusion and nights of infusions]: Calculated as total duration in N3/total sleep time and total duration in REM/total sleep time. Baseline measures are averages of taken from 2-3 sleep recordings before infusions. Post-infusion average is averaged from sleep recordings taken on the evenings of morning propofol infusions Reported change is infusion nights average - baseline average.
• Evaluate Changes in Cognitive Function (MoCA) Between Pre-infusion Baseline and 3-weeks Post Infusion [Two time points: baseline measure (approximately 1 week before the first infusion) and 3-weeks after second infusion]: Evaluate changes in cognitive function Change in Cognitive Performance on the Montreal Cognitive Assessment (MoCA). Total score of the MoCA is from 0-30, Normal: 26-30, Mild Cognitive Impairment (MCI): 18-25, Moderate Cognitive Impairment: 10-17, Severe Cognitive Impairment: <10 Examine potential positive or negative changes in cognition that may be associated with propofol infusion. Reported change is post-infusion - baseline. Positive change indicated improvement. Negative change indicates worsening of cognition.
• Number of Participants Able to Provide Complete Cognitive Assessment (Fluid Cognition) Using NIH Toolbox [pre-infusion baseline and approximately 3-weeks after the 2nd infusion]: Evaluate the feasibility in evaluating changes in cognitive function using NIH toolbox

Other outcomes

• Number of Participants Able to Provide Sleep Diary Data on Circadian Rhythms [Three-week period spanning pre- and post propofol infusions]: Examine feasibility of acquiring propofol-associated changes on circadian rhythms using a sleep diary These measures are important for evaluating feasibility of collection in Phase II.
• Anhedonia During Study Participation [Baseline, 1-week Post Infusion, 3-week Post Infusion, and 10-weeks Post Infusion]: Examine the feasibility of acquiring propofol-associated changes on anhedonia Measure of anhedonia with the Snaith-Hamilton Pleasure Scale (SHAPS), scale: rated on a 4-point Likert scale: 0 = strongly disagree, 1 = disagree, 2 = agree, 3 = strongly agree, Scoring: Items marked with * (questions 2, 4, 5, 7, 9) are reverse coded with answer choices as follows: definitely agree, agree, disagree, and strongly disagree. All other items are sum-scored. (total score ranges from 0-14). A higher score indicates greater anhedonia (lower pleasure), with scores <=2 typically considered normal, while scores >=3 indicate significant anhedonia.Total score is tabulated from summation of subscores, with a greater score indicating more anhedonia. Medians across the population are reported for each time point. These measures are important for evaluating the feasibility of collection in Phase II.
• Depression Severity During the Study Period [Baseline, 1-week after 2nd Infusion, 3-week after 2nd Infusion and 10-week after the 2nd infusion]: Examine feasibility of acquiring propofol-associated changes on depression symptoms Measure of Depressive Symptoms using the Montgomery-Åsberg Depression Rating Scale (MADRS), total score ranges from 0-60, 0-6: No depression, 7-19: Mild depression, 20-34: Moderate depression, and 35-60: Severe depression. Baseline measures were taken within 1-week of the first propofol infusion. This assesses for changes in depression relative to the 2nd infusion of propofol. No assessments were taken during the 2-6 days between the first and second infusions. These measures are important for evaluating feasibility of collection in Phase II.
• Changes in Affect Following Propofol Infusions [within an hour before infusion and within 30-minutes after awakening from infusion]: Examine the feasibility of acquiring propofol-associated changes on affect Measure of affect using the Feelings Scale, (-5 to 5) as follows: -5 = Very Bad, -3 = Bad, -1 = Fairly Bad, 0 = Neutral, 1 = Fairly Good, 3 = Good, 5 = Very Good This assesses any affect immediately after propofol infusions These measures are important for evaluating the feasibility of collection in Phase II. Assessments were taken before and after both infusions. Change is the post - pre-infusion score for an individual infusion. Greater change = higher affect. Changes for each individual were the average across both infusions. Median changes are reported across all participants.

Sex: All, ages: 60 Years to any

Inclusion Criteria:

* Provision of signed and dated informed consent form
* Stated willingness to comply with all study procedures and availability for the duration of the study
* Age 60 or greater
* English speaking (as an interpreter will not be readily available should a participant need to convey any safety concerns during the propofol infusion sessions or require guidance on conducting at-home sleep recordings)
* Treatment-resistant Depression (non-responsive to at least two adequate trials of oral antidepressants for current episode).

Exclusion Criteria:

* Presence of symptomatic coronary artery disease
* Presence of marked congestive heart failure/cardiomyopathy (NYHA > Class III, LVEF <40%, greater than mild RV systolic dysfunction)
* Prior reaction to propofol
* Resting heart rate < 50 bpm
* Treatment with Electroconvulsive therapy/Transcranial Magnetic Stimulation/vagal nerve stimulation within 6 weeks
* Body mass index > 35
* C-SSRS of 4 or greater (active suicidal ideation with some intent and with/without a specific plan)
* MoCA score < 23 (at least mild dementia)
* Non-prescribed used of amphetamines, opioids, marijuana, cocaine, or phencyclidine
* Intake of > 14 beers/week (or equivalent)
* Anesthetic exposure in the past 4 weeks
* Concurrent use of benzodiazepines > 2 mg/day lorazepam or equivalent, trazodone > 50 mg/day, or gabapentin > 600 mg/day.

Participant flow

Outcome results

• Number of Participants Without Serious Adverse Events During Propofol Infusions (Primary), Count of participants, Participants: Propofol Infusion 16
• Change in SWA During Propofol Infusions Compared to Awake Baseline Before Infusion (Primary), Median, uV squared: Propofol Infusion 18.6 (0 to 35.7)
• Proportion of Infusion Completers With Augmentation of Sleep SWA After Propofol Infusion (Primary), Count of participants, Participants: Propofol Infusion 6
• Effects on Suicidality (Secondary), Median, units on a scale: Propofol Infusion 1 (1 to 2)
• Changes in N3 Duration, REM Duration, Total Sleep Time (Post-infusion Change Relative to Baseline) (Secondary), Median, minutes: Propofol Infusion 17.75 (1.79 to 33.25)
• Change in Delta Sleep Ratio (Infusion Nights - Baseline) (Secondary), Median, unitless: Propofol Infusion 0.075 (-0.467 to 0.440)
• Changes in Proportion of Total Sleep Time in N3, Proportion of Total Sleep Time in REM (Secondary), Median, percentage of total sleep time: Propofol Infusion 4.5 (1.3 to 11.2)
• Evaluate Changes in Cognitive Function (MoCA) Between Pre-infusion Baseline and 3-weeks Post Infusion (Secondary), Mean, score on a scale: Propofol Infusion 0.14 +/- 2.6
• Number of Participants Able to Provide Complete Cognitive Assessment (Fluid Cognition) Using NIH Toolbox (Secondary), Count of participants, Participants: Propofol Infusion 8
• Number of Participants Able to Provide Sleep Diary Data on Circadian Rhythms (Other pre specified), Count of participants, Participants: Propofol Infusion 15
• Anhedonia During Study Participation (Other pre specified), Median, score on a scale: Propofol Infusion 4 (1.5 to 9.5)
• Depression Severity During the Study Period (Other pre specified), Median, score on a scale: Propofol Infusion 25 (23 to 28)
• Changes in Affect Following Propofol Infusions (Other pre specified), Median, score on a scale: Propofol Infusion 0 (-1 to 1)

Adverse events

Time frame: 13 weeks beginning from the time of enrollment to the completion of the study.

Other adverse events by term

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• Doghramji K, Jangro WC. Adverse Effects of Psychotropic Medications on Sleep. Psychiatr Clin North Am. 2016 Sep;39(3):487-502. doi: 10.1016/j.psc.2016.04.009. Epub 2016 Jun 24. PMID 27514301
• Rios RL, Green M, Smith SK, Kafashan M, Ching S, Farber NB, Lin N, Lucey BP, Reynolds CF, Lenze EJ, Palanca BJA; SWIPED Study Team. Propofol enhancement of slow wave sleep to target the nexus of geriatric depression and cognitive dysfunction: protocol for a phase I open label trial. BMJ Open. 2024 May 30;14(5):e087516. doi: 10.1136/bmjopen-2024-087516. PMID 38816055
• Rios RL, Kafashan M, Hyche O, Lenard E, Lucey BP, Lenze EJ, Palanca BJA. Targeting Slow Wave Sleep Deficiency in Late-Life Depression: A Case Series With Propofol. Am J Geriatr Psychiatry. 2023 Aug;31(8):643-652. doi: 10.1016/j.jagp.2023.03.009. Epub 2023 Mar 28. PMID 37105885

• Study Protocol and Statistical Analysis Plan (PDF, 2023-01-30)
• Informed Consent Form (PDF, 2025-05-20)

• Ben Palanca, MD PhD, Principal investigator, Washington University School of Medicine

NIH grants: U01MH128483