Herbal medicine use in adults experiencing anxiety: Understanding a complex health behaviour

Anxiety is a significant mental health problem in Australia, and Australians
are high users of herbal medicines. Little is known about how adults experiencing anxiety are using herbal medicines in contemporary Australia. Therefore, the overall aims of this research are to describe the herbal medicine use behaviour of Australian adults who experience anxiety, explore their beliefs and attitudes to using herbal medicines, and identify the key predictors of intention to use herbal medicines for anxiety symptoms.

This research used a mixed-methods sequential exploratory design. First, a
critical literature review was conducted with two aims: to identify the prevalence of herbal medicine use in adults with anxiety, and to identify the beliefs and attitudes that predict the intention to use herbal medicines or actual herbal medicine use behaviour. The prevalence of herbal medicine use in people experiencing anxiety ranged from 2.39% to 22% across four countries. A number of beliefs and attitudes were found to predict attitudes to and use of CAMs and herbal medicines.

Second, a qualitative study explored the beliefs and attitudes towards herbal
medicine among adults who experienced anxiety. Using purposive sampling eight Australian adults with a subjective experience of anxiety who used herbal medicines were interviewed. Critical thematic analysis revealed three major themes: herbal medicines being different to pharmaceuticals, evidence and effectiveness, and barriers to herbal medicines. Findings informed the development of a quantitative questionnaire.

Third, a cross-sectional online survey was conducted. A questionnaire was
developed that measured demographics, subjective experience of anxiety, herbal and pharmaceutical medicine use, communication with health care providers, information sources use, disclosure of herbal medicine use, and beliefs and attitudes to herbal medicine use. Two validated measures of anxiety were also used. Purposive criterion sampling was used to recruit adults representative of the Australian population who used herbal medicines and experienced anxiety (N = 400). Findings supported previous research that Australian adults are using herbal medicines to treat anxiety symptoms. They are consulting with a range of health practitioners; however, there were high rates of self-prescription of herbal medicines with many people not disclosing their herbal medicine use to doctors or other health professionals, and using non-professional information sources. People with an anxiety disorder diagnosis were more likely to use
herbal medicines than those without, and those with more severe anxiety symptoms in the previous week had greater current use of herbal medicines for anxiety symptoms compared to those with milder symptoms.

The theory of planned behaviour was used to develop a hypothesised
theoretical model predicting the intention to use herbal medicines for anxiety symptoms that was tested using structural equation modeling. The model was supported and demonstrated that attitudes to herbal medicines, subjective norms, control beliefs, and anxiety symptoms were significant predictors of intention to use herbal medicines for anxiety symptoms.

The research findings provide an understanding of herbal medicine use
behaviour in adults who experience anxiety that has implications for conventional and non-conventional health practitioners who treat anxiety, people with anxiety symptoms who use herbal medicines, policy makers in the area of herbal medicine regulation, and will guide future research.