Enhancement of Sleep Quality and Mood Following Supplementation With Lemon Balm in an Adult Population (Lemslp)

A validated measure of sleep assessing qualities and patterns within the last month of sleep habits in adults. Seven components of sleep (quality, latency, duration, efficiency, disturbance, use of sleep medication, daytime dysfunction) will be summed to achieve a global PSQI score ranging from 0 to 21 points, where scores above 5 indicates sleep problems.

Passive motion tracking of sleep-wake patterns (heart rate variability) will be recorded via a wrist-worn research-grade actiwatch. The actiwatches will be secured on the participant's wrist throughout the study period. To cross-examine the actiwatch data, an in-house standardised daily sleep diary will measure sleep quality, sleep duration and sleep latency (how many times awoken during sleep time) (Carney et al., 2012; Orchard et al., 2020) where meaningful sleep outcomes will be manually inputted into actiwatch software at the end of sleep monitoring, as per standard practice in sleep research.

Determination of changes in circadian sleep-wake patterns after 4-weeks daily 300mg lemon balm treatment by assessing diurnal sleep neurohormones, melatonin and cortisol. Changes in melatonin and cortisol will be assessed using 12 salivary self-test sampling kits taken in two windows (6 samples per window), within 24h before baseline day and within 24h before post-intervention day. For each test day, two samples will be taken first thing in the morning, 11am, 5pm and a final two samples in the evening. Sleep neurohormones will then be assessed against subjective sleep scores.

Examination of gut responses to mood and sleep physiology changes after 4-weeks daily 300mg lemon balm treatment by assessing changes in faecal microbiota levels. Two samples will be collected over the entire study. Microbiome diversity will be determined using self-test stool sampling kits taken in two windows, within 24h before baseline day and within 24h before post-intervention day. Faecal microbiota will then be compared to subjective sleep and mood scores.

A validated 7-item instrument designed to assess the nature, severity and impact of both nighttime and daytime components of insomnia within the last month. The scale ranges from 0 to 28 where higher scores indicate more severe insomnia.

A 10-item self-report slider scale to evaluate ease of getting to sleep, sleep quality, ease of waking and behaviour following wakefulness. Higher scores indicate better sleep quality.

A validated 10-item questionnaire to measure levels of perceived stress. The scale ranges from 0 to 40 points with higher scores indicating greater stress levels.

General positive affect for assessing trait mood over the past month will be calculated by adding the values of 10 positive items in correspondence with the original PANAS, ranging from 0-50 where higher scores indicate positive affect. In addition, the expanded Positive and Negative Affect Schedule-X will assess higher order scales Surprise, Joviality,Self-Assurance, Attentiveness, and Serenity and these collective scores combined with general positive affect range from 0 to 170 points, where higher scores indicate better mood.

General positive affect for assessing transient mood as the respondent feels in the present moment will be calculated by adding the values of 10 positive items. Scores range from 0-50 points where higher scores indicate positive affect.

General positive affect for assessing trait mood over the past month will be calculated by adding the values of 10 negative items in correspondence with the original PANAS, ranging from 0-50 where higher scores indicate negative affect. In addition, the expanded Positive and Negative Affect Schedule-X will assess higher order scales Fear, Sadness, Guilt, Hostility, Shyness, Fatigue and these collective scores combined with general negative affect range from 0 to 170 points, where higher scores indicate worse mood.

General negative affect for assessing transient mood as the respondent feels in the present moment will be calculated by adding the values of 10 negative items, ranging from 0-50 where higher scores indicate negative affect.

A validated 21-item measure to assess the severity of depression, anxiety and stress components, with 7 items per component. Each item is scored from 0-3 where higher scores indicate higher levels of distress in anxiety (scores range from 0 to >20), depression (0 to >28) and/or stress (0 to >34).

A self-report 7-item questionnaire to assess perception of frequency and severity of fatigue over the past 2 weeks. Global fatigue scores range from 0 to 31, where higher scores indicate greater fatigue.

An in-house Givaudan wellbeing metric, and patent approved (WO2020165463). This 18-item scale measures transient feelings in the present moment assessing 9 positive and 9 negative attributes (reverse scored) to contribute to overall wellbeing scores. Scores range from 0 to 180, where higher scores indicate higher wellbeing.