Pilot Study: Investigating Mood Changes After Slow-wave Enhancement

Pilot Study: Investigating Mood Changes After Slow-wave Enhancement

The aim of this pilot project proposal is to test the hypothesis that decreased sleep slow-wave activity (SWA) observed in individuals with major depressive disorder (MDD) is related to mood dysfunction, and that manipulating SWA may serve to improve mood by normalizing SWA regulation. The investigators propose to enhance SWA during nighttime sleep in a group of 20 antidepressant-free males and females age 25-50 with varying degrees of impairment in mood. Each participant will undergo one baseline night of sleep in the laboratory and then will sleep with the SmartSleep Headband nightly for two weeks in their own home. For one week, slow-wave sleep will be enhanced. On the alternate week, sleep will not be changed. Following the two weeks of sleeping with the device, participants will then spend another night in the sleep laboratory to assess changes in sleep. Mood will be assessed by self-report and clinician-administered scales following the baseline night of sleep, virtually after the first experimental week, and at the conclusion of the study.

Inclusion Criteria:

1. Age 25-50 years.

2. Primary language is English.

3. Normal cognition.

4. Normal (or corrected-to-normal) vision and hearing.

5. Current depression.

6. Stable, normally-timed sleep-wake cycle as determined by interview, 1-week daily sleep log, and 1-week wrist actigraphic evidence, and defined by:

   1. Habitual nocturnal sleep duration between 6h and 9h.
   2. Habitual bedtime between 9pm-12am.
   3. No evidence of habitual napping.

Exclusion Criteria:

1. Current or prior medical condition that could interfere with collection or interpretation of data, based on medical history.
2. History of stroke, epilepsy, brain scarring, or head injury causing unconsciousness.
3. Independent/Intrinsic sleep disorder other than insomnia based on history or polysomnogram.
4. Recent use of psychoactive medications or medication thought to impact sleep or CNS function, as determined by investigators (e.g. SSRIs, benzodiazepines, glutamate modulators, gabapentin).
5. History of or current psychiatric conditions that increase study risk or grossly impair CNS function (e.g., current anorexia or bulimia, history of substance dependence or current substance abuse, lifetime history of psychosis).
6. Lifetime history of electroconvulsive therapy.
7. Pregnancy as determined by self-report.
8. Travel beyond 2 time zones in the 2 months before study.
9. Unwillingness to refrain from using alcohol or caffeine during the study.