Abstract
Aromatherapy is often considered an alternative or complementary therapy and probably suffers as a result. Complementary medicine seems to survive and prosper in the absence of supporting scientific evidence and in the presence of charlatans and gullible patients. Not so aromatherapy which, perhaps uniquely, has supporting it a growing body of cogent evidence and plausible explanations for its effects. In this issue, Moss and Oliver describe the results of their experiments with 1,8-cineole, the major constituent of rosemary essential oil. Subjects were exposed to rosemary oil aroma for varying lengths of time and their cognitive performance, mood and, most importantly, plasma 1,8-cineole were measured. Exposure to the essential oil improved both mood and cognition, and these improvements correlated with plasma levels of 1,8-cineole. The study thus demonstrated that 1,8-cineole is absorbed by inhalation, affording plasma levels that were seemingly therapeutically active. These observations, combined with earlier work showing that 1,8-cineole enhances cholinergic, noradrenergic and dopaminergic functions complete a full evidence-based picture of therapeutic activity of rosemary oil. Although a small study (20 subjects), this experiment has clear implications.
It is probably true to say that, within medicine itself, there are complementary treatments: those without much evidence to recommend them but might in theory be useful. There are many examples in psychiatry, one being the use of modafinil (and its isomer armodafinil) in the treatment of negative and cognitive symptoms of schizophrenia. Laura Wittkampf and colleagues review in this issue what little evidence there is to support this practice. A total of 15 studies were examined, 10 of these being randomized, controlled trials. They found little to support a role for modafinil in decreasing fatigue or inactivity and contradictory evidence for activity against cognitive deficits. Bigger, longer, dose-ranging studies are clearly needed.
A third paper in this issue examines in some detail a known adverse consequence of risperidone treatment: hyperprolactinaemia. This is common outcome of the use of antipsychotics and one which can occur as frequently with some atypical antipsychotics (risperidone, amisulpride) as with older, conventional drugs. Debate continues as to the clinical relevance of raised prolactin as it is often superficially symptomless (or at least patients rarely complain). Nonetheless, hyperprolactinaemia is known to cause menstrual disturbance, lowered libido, gynaecomastia and galactorrhoea, and suspected of causing reductions in bone mineral density in long-term use. Jeffery Bishop and coworkers examined prolactin and markers of bone resorption in 30 subjects given risperidone. Prolactin levels increased by more than 400% while bone resorption decreased significantly over the first 4 weeks of treatment. This is the first time this effect on bone integrity has been demonstrated to be an acute effect. The two outcomes were related at a trend level.
All three papers in this issue clearly emphasize the need for well-constructed research designed carefully to disprove or otherwise theories of drug action and to examine relationships that might support any positive findings.