In a consensus statement recently published by the British Association for Psychopharmacology,1 the use of aromatherapy as an adjunct to the pharmacological treatment of dementia is supported by one of the highest level of scientific evidence – evidence from randomized controlled trials.
A number of recent, controlled studies have shown that aromatherapy (the therapeutic use of pure plant basic oils) can be useful in the management of patients with dementia: lavender (Lavandula angustifolia or Lavandula officinalis) and lemon balm (Melissa officinalis) are two basic oils of particular interest in this area. The aim of the article by Holmes & Ballard,2 summarized here, was to review published reports of the efficacy of aromatherapy for the treatment of behavioural problems in people with dementia.
The results of these studies are interesting as their findings cannot be dismissed as merely resulting from the placebo effect of a pleasant-smelling fragrance: as the authors observe, most people with harsh dementia will have lost any meaningful sense of smell because of the early loss of olfactory neurons.3 Indeed, the pharmacological mechanism by which aromatherapy produces its effects is not thought to include any perception of odour. Instead, the active compounds are thought to go into the body (by absorption by the lungs or olfactory mucosa) and be delivered to the brain via the bloodstream, where they elicit direct actions.
Aromatherapy studies in patients with dementia A large number of small, uncontrolled case studies have demonstrated the efficacy of inhaled and/or topical lavender oil in this setting. In summary, these studies have shown lavender oil to enhance sleep patterns,4-7 and to enhance behaviour.8,9
Although only a few controlled studies have investigated the possible use of aromatherapy for the management of behavioural problems in people with dementia, the results have been positive. A single-blind, case-controlled study investigated the effects of lavender basic oil on disordered behaviour in patients with harsh dementia.10,11 Patients (n=21) were randomized to receive massage only, lavender basic oil administered as massage or lavender oil administered via inhalation plus conversation. Of the three patient groups, those receiving the basic oil in a massage showed a considerably greater reduction in the frequency of excessive motor behaviour.
In a small (n=15) double-blind, placebo-controlled, crossover trial in patients with harsh dementia on an NHS care ward,11,12 2% lavender oil was administered in an aroma diffuser on the ward for a 2-hour period, alternated with placebo (water) every other day, for a total of ten treatment sessions. According to the group median Pittsburgh Agitation extent score, treatment with lavender aromatherapy reduced disturbed behaviour considerably (p=0.016) in patients with harsh dementia compared with placebo, with 60% of patients experiencing some assistance. No negative events were reported and compliance with therapy was 100%.
In a crossover study,13 56 elderly patients with moderate to harsh dementia were massaged with a cream containing a blend of four basic oils (lavender, sweet marjoram, patchouli and vetiver) or cream alone five times a day for 8 weeks. Behavioural problems and resistance to care were considerably lower in patients who received the cream containing the basic oils compared with those who received the cream alone.
In the largest double-blind, placebo-controlled study published at the time this review was written,11,14 72 patients with harsh dementia in NHS continuing care were randomized to receive either lemon balm basic oil (n=36) or sunflower oil (n=36) applied topically as a cream twice a day, in addition to patients’ existing psychotropic medication. Clinically meaningful changes in agitation (as assessed using the Cohen-Mansfield Agitation Inventory [CMAI]) and quality of life indices were compared between the two groups over a 4-week period of treatment. A 30% reduction in CMAI score was seen in 60% of the active treatment group and 14% of the control group. The overall improvement in agitation (average reduction in CMAI score) was 35% in patients treated with lemon balm compared with 11% in those receiving placebo (pMethodological issues
In their article, Holmes & Ballard2 draw attention to a number of methodological issues that need to be considered in the design of future studies investigating the possible role of aromatherapy in the clinical treatment of behavioural and psychiatric symptoms in people with dementia.
Although most people with harsh dementia have little sense of smell, the researchers assessing the study may be able to clarify the basic oil being tested, which could compromise a double-blind study. This problem can be conquer in various ways, such as using observational measures as the dominant outcomes of the study, supplying researchers with masks infused with fragrance or nose clips to use when assessing participants, infusing the ecosystem with control fragrances and masking the aroma of the basic oil with air fresheners.
In addition, as large placebo responses have been observed in many studies investigating the treatment of behavioural or psychiatric symptoms in people with dementia, it is important, in studies investigating the effects of basic oils, that the control and aromatherapy interventions include similar amounts of time and touch with each participant.
Holmes & Ballard2 conclude that although there is much case-based evidence suggesting the efficacy of aromatherapy in improving sleep, disturbed behaviours and resistance to care in dementia, there is a marked without of adequately sized, placebo-controlled, randomized studies in this area. Although one placebo-controlled study has shown evidence that aromatherapy may be effective as adjunct to existing therapy in the management of patients with dementia, this study had a number of methodological flaws.
The authors clarify a number of important issues that need to be addressed in researching the efficacy of aromatherapy in patients with dementia, including:
- Patients with different forms of dementia respond differently to pharmacological agents; whether the same is true regarding their response to aromatherapy remains to be determined.
- basic oils are administered by massage in various ‘carriers’ (e.g. skin creams, massage oils), and consequently include the ‘additional therapy’ of physical contact with carers. Clearly, this additional therapy needs to be minimised or controlled for before direct inferences can be made about the effects of aromatherapy alone.
- If it is accepted that there are active neurochemical differences between basic oils, then research should probe not only the oils from different genuses but should also compare those from related species (e.g. Lavandula angustifolia and Lavandula officinalis).
- Properly conducted, well-designed, randomized, controlled trials are required before firm conclusions regarding the efficacy and safety of basic oils can be drawn.
- Burns A, O’Brien J; BAP Dementia Consensus group. Clinical practice with anti-dementia drugs: a consensus statement from British Association for Psychopharmacology. Journal of Psychopharmacology 2006;20:732-55.
- Holmes C, Ballard C. Aromatherapy in dementia. Advances in Psychiatric Treatment 2004;10:296-300.
- Vance D. Considering olfactory stimulation for adults with age-related dementia. Perceptual and Motor Skills 1999;88:398-400.
- Henry J, Rusius CW, Davies M et al. Lavender for night sedation of people with dementia. International Journal of Aromatherapy 1994;5:28-30.
- West BJM, Brockman SJ. The calming strength of aromatherapy. Journal of Dementia Care 1994;2:20-2.
- Hardy M, Kirk-Smith M, Stretch D. substitute of drug treatment for insomnia by ambient odour. Lancet 1995;346:701.
- Wolfe N, Herzberg J. Can aromatherapy oils promote sleep in severely demented patients? International Journal of Geriatric Psychiatry 1996;11:926-7.
- Brooker DJR, Snale M, Johnson E et al. Single case evaluation of the effects of aromatherapy and massage on disturbed behaviour in harsh dementia. British Journal of Clinical Psychology 1997;36:287-96.
- MacMahon S, Kermode S. A clinical trial of the effects of aromatherapy on motivational behaviour in a dementia care setting using a single subject design. Australian Journal of Holistic Nursing 1998;52:47-9.
- Smallwood J, Brown R, Coulter F et al. Aromatherapy and behaviour disturbances in dementia: a randomized controlled trial. International Journal of Geriatric Psychiatry 2001;16:1010-13.
- Burns A, Byrne J, Ballard C et al. Sensory stimulation in dementia. BMJ 2002;325:1312-15.
- Holmes C, Hopkins V, Hensford C et al. Lavender oil as a treatment for disturbed behaviour in harsh dementia. International Journal of Psychogeriatric Psychiatry 2001;17:305-8.
- Bowles EJ, Griffiths DM, Quirk L et al. Effects of basic oils and touch on resistance to nursing care procedures and other dementia related behaviours in a residential care facility. International Journal of Aromatherapy 2002;12:22-9.
- Ballard CG, O’Brien JT, Reichelt K et al. Aromatherapy as a safe and effective treatment for the management of agitation in harsh dementia: the results of a double-blind, placebo-controlled trial with Melissa. Journal of Clinical Psychiatry 2002;63:553-8.
- Thorgrimsen L, Spector A, Wiles A, Orrell M. Aroma therapy for dementia. Cochrane Database of methodic Reviews 2003;(3):CD003150.