Interview conducted by April Cashin-Garbutt, BA Hons (Cantab)
Please could you give a brief introduction to anxiety, depression and insomnia drugs? How do they work?
Anxiety, depression and insomnia drugs have been commonly used to treat mental and emotional disorders, or improve sleep-related problems. They affect the central nervous system (CNS) by interacting with a variety of neurotransmitters, and as a result, alter chemical levels in the brain that cause a various changes in behavior and impair the cognitive and psychomotor abilities.
How many people take anxiety, depression and insomnia drugs?
The frequency of people taking anxiety, depression and insomnia drugs vary across different areas and countries. Approximately, 5-10 percent of people take anxiety, depression and insomnia drugs, and estimated prevalence of taking these drugs may be even higher in women and/or the elderly than in general population.
How did your research into these drugs and the risk of having a driving accident originate?
While most studies have mainly examined the effect of benzodiazepines on driving accidents, limited studies (maybe one or two) have comprehensively and simultaneously examined the effect of various classes of psychotropic drugs such as anxiety, depression and insomnia drugs on driving accidents in a single nationwide registry population-based study.
More importantly, most studies have previously done in Caucasian populations, only few in Asian populations.
What did your research show?
The findings from our research showed that exposure to anxiety, depression and insomnia drugs was significantly associated with an increased risk of motor vehicle accidents.
Moreover, significant dose effects in some types of anxiety, depression and insomnia drugs were observed on the risk of experiencing a driving accident.
Did your work show that there was a difference in the risk of having a driving accident with different types of drugs?
Based on the results from this work, we found that subjects taking antidepressants (adjusted odds ratio (AOR)=1.73, 95% confidence interval (CI)=1.34-2.22 for one month; AOR=1.71, 95%CI=1.29-2.26 for one week; and AOR=1.70, 95%CI=1.26-2.29 for one day) tended to have higher risk of having a driving accident than those taking benzodiazepines (AOR=1.56, 95%CI=1.38-1.75 for one month; AOR=1.64, 95%CI=1.43-1.88 for one week; and AOR=1.62, 95%CI=1.39-1.88 for one day). However, further investigation will be warranted to validate this observed difference.
Did your research demonstrate that there was a causative relationship between these drugs and the risk of having a driving accident, i.e. did your work show that the anxiety, depression and insomnia drugs caused the increased risk of driving accident, or could this be just be an association?
We have demonstrated a temporal relationship between these drugs and the risk of having a driving accident in this research. We defined “psychotropic users as having a prescribed claims record of psychotropic drug supply prior to the index date—the first outpatient claim of a motor vehicle accident” in this work. As such, we showed that the anxiety, depression and insomnia drugs increased the risk of driving accidents.
What impact do you think your research will have?
Our findings underscore that subjects taking these psychotropic medications should pay particular attention to their driving performance in order to prevent the occurrence of motor vehicle accidents. Therefore, I would suggest clinicians should carefully evaluate the condition of their patients before prescribing psychotropic drugs. In addition, it is also important that clinicians provide their patients with accurate advice, and advise their patients not to drive, especially under the influence of psychotropic medications.
Do you have any plans for further research into this area?
Yes, we are planning to expand our current research in this area. For example, we did not consider weather conditions, accident-occurrence date (weekday or weekend) and/or time of the day in this work. As such, we are planning to link our registry medical claims data to the data collected by the Central Weather Bureau in Taiwan to account for this issue and further confirm the effect of anxiety, depression and insomnia drugs on driving accidents.
Would you like to make any further comments?
Not at this point. However, as indicated in the press release of British Journal of Clinical Pharmacology, I would highly suggest that “Doctors and pharmacists should choose safer treatments, provide their patients with accurate information and advise them not to drive while taking psychotropic medications.”
Where can readers find more information?
Readers can fine more information in the following link: http://www.wiley.com/WileyCDA/PressRelease/pressReleaseId-104997.html
About Hui-Ju Tsai
Dr. Tsai is an Associate Investigator in the Division of Biostatistics and Bioinformatics, Institute of Population Health Sciences, National Health Research Institutes in Taiwan; and an Adjunct Assistant Professor in the Department of Pediatrics, Northwestern University Feinberg School of Medicine.
Dr. Tsai received her education and training in epidemiology, molecular biology, and statistical genetics. Her research interests are in the fields of genetic epidemiology, psychiatric epidemiology and pharmacoepidemiology. She has published over 40 peer-reviewed papers in these related fields, including first-author papers in the American Journal of Human Genetics, and the Journal of Allergy and Clinical Immunology; corresponding-author papers in the British Journal of Psychiatry, and Obstetrics and Gynecology; and coauthor papers in Biologic Psychiatry, and Addiction Biology.