Lee KB, Latif S, Kang YS. Differences in neurotransmitters level as biomarker on sleep effects in dementia patients with insomnia after essential oils treatment. Biomol Ther (Seoul). May 2023;31(3):298-305. doi:10.4062/biomolther.2023.014.
Insomnia is a condition that disturbs sleep onset, maintenance, or quality and affects 6-20% of the population throughout the world. Secondary insomnia can be caused by underlying, medical, neurological, or psychiatric conditions including Alzheimer's disease (AD) and dementia. AD and dementia patients often experience insomnia, general tiredness, lethargy, irritability, and concentration or memory problems. This is due to the general loss of neurotransmitters. The prevalence of dementia has doubled yearly since 2010, and 25-35% of AD patients experience sleep disorders. Treatments for managing insomnia include benzodiazepine; however, prolonged use can cause drug dependence, tolerance, bad sleep, rebound insomnia, deterioration in recognition function, and reduced effect. Aromatherapy has been suggested to be a natural, safe therapy for insomnia and can be used for extended periods. Three essential oils shown to improve sleep quality include lavender (Lavandula spp., Lamiaceae), valerian (Valeriana officinalis, Caprifoliaceae), and Roman chamomile (Chamaemelum nobile, Asteraceae). The authors conducted a small study to evaluate the effects of lavender, valerian, and Roman chamomile essential oils on the quality of sleep and neurotransmitter level in patients with dementia experiencing insomnia.
This study was conducted at a nursing home in the Republic of Korea. Inclusion and exclusion criteria were not stated; however, it was stated that the men and women patients were diagnosed with dementia by neuropsychiatrists, were using urine bags or portable urinals, were between the ages of 71 and 94, and had a sleep disorder.
The study examined the effects of lavender, valerian, and Roman chamomile individually and in three different formulas. The three different formulas included the valerian:lavender:Roman chamomile ratio of 1:2:2 (A), 1:3:1 (B), and 1:1:3 (C). Essential oils were obtained from Absolute Aroma Co (Hampshire, United Kingdom) and were verified using gas chromatography mass spectrometry. Essential oils were diluted to 3% in jojoba (Simmondsia chinensis, Simmondsiaceae) oil.
Patients underwent two weeks of each aromatherapy course with a two-week break time between each course after a skin test, blood pressure check, and body temperature check. The course included baseline (control), jojoba treatment (placebo), break time, 3% valerian treatment, break time, 3% lavender, break time, 3% Roman chamomile oil, break time, 3% mixed oil A, break time, 3% mixed oil B, break time, and 3% mixed oil C. Oil was massaged on the faces and hands for 1-2 minutes 1-2 h before their bedtime by a nurse. Blood and 24 h-urine were collected at 9:00 a.m. before each 2-week aromatherapy course and the day after completing the course. Blood and urine analysis included serum cortisol, serotonin, norepinephrine, and free cortisol levels. Frequency of awakenings every night, the presence of excessive daytime sleepiness daily, and total sleep hours were recorded by nurses. The neuropsychiatric inventory-questionnaire (NPI-Q) was utilized to assess the severity and distress of symptoms, the geriatric depression scale: short form (GDS:SF) was used to analyze depression, and the national sleep foundation sleep diary was employed to track patient's sleep.
There were 13 patients who underwent the study. Six of the patients were male, and seven were female. The mean age was 84 years. There were no significant differences in serum serotonin compared to baseline for any of the single aromatherapy courses. After using lavender oil for two weeks, there was a significant decrease in free cortisol levels in the urine and a significant decrease in number of days taking a nap. After using Roman chamomile for two weeks, there was a significant increase in the norepinephrine levels in urine, a significant decrease in free cortisol levels in urine, and a significant increase serum serotonin level. Lastly, after using valerian for two weeks, there was a significant decrease in the frequency of night awakenings, and the number of excessive daytime sleepiness; and a significant increase in serum serotonin level.
It was found mixture A led to a significant increase in serum serotonin levels. Mixture A also resulted in reduced frequency of night awakenings and the number of days taking a nap. Mixture B indicated an increase in serotonin and a decrease in free cortisol in urine, the frequency of night awakenings and the number of days taking a nap. Mixture C showed a significant increase in norepinephrine. All groups saw a significant decrease in NPQ-1 and GDS:SF indicating a decrease in anxiety, depression, alertness, and wandering.
The authors conclude that valerian shows the most beneficial effect on sleep in patients with dementia; however, valerian is not an ideal option due to its pungent smell and toxic substance thujone. The blended essential oils may be the best option to deliver valerian at a lower but still effective amount to improve sleep quality. More research is needed to understand the efficacy, safety, and long-term effects of valerian, Roman chamomile, and lavender essential oils and blends.
The authors do not mention if they have a conflict of interest or not. It is noted the study was supported by the Sookmyung Women’s University in Korea.