Trends in prescribing for anxiety in UK primary care

Problem

Prescribing of antidepressants - for any indication and for depression - has increased substantially over the past two decades. However, little is known about trends in the prescribing of these and other drugs (such as benzodiazepines, beta-blockers, anticonvulsants and antipsychotics) for the treatment of anxiety in UK primary care. Several changes may have affected prescribing for anxiety: the introduction of IAPT in 2007/8; the 2008 economic recession; and the 2011 NICE anxiety guidelines recommendation that antipsychotics should not be prescribed for anxiety. Therefore, this study examined trends in prescribing for anxiety in UK primary care between 2003 and 2018.

Approach

We used data from adults (n=2,569,153) registered with UK general practices that contributed to the Clinical Practice Research Datalink (CPRD) between 2003-2018. Annual prevalence rates and incidence rates with 95% confidence intervals (CIs) were calculated for anxiolytic prescriptions for patients with anxiety. Analyses were conducted for any anxiolytic prescription, and separately for each drug class. Duration of treatment for those starting medication in each drug class was also examined.

Findings

Prevalence of prescribing of any anxiolytic increased from 24.8/1000 person-years at risk (PYAR) in 2003 to 43.6/1000PYAR in 2018. This was driven by increases in those starting treatment, rather than an increase in long-term use. Between 2003 and 2008, the incidence of any anxiolytic prescription decreased from 12.8/1000PYAR to 9.3/1000PYAR; after which incidence remained fairly constant before rising to 13.1/1000PYAR in 2018. A similar trend was seen for the incidence of antidepressant prescriptions. The incidence of beta-blocker prescriptions increased over the 16-year period, from 2.3/1000PYAR in 2003 to 4.1/1000PYAR in 2018. Whereas the incidence of benzodiazepine prescriptions decreased from 6.4/1000PYAR in 2003 to 4.6/1000PYAR in 2018. Antipsychotics and anticonvulsants were prescribed infrequently, although incidence gradually increased between 2003 and 2018. Whilst long-term prescribing of benzodiazepines declined over the study period, just under half the prescriptions in 2017 were longer than the recommended maximum of 4 weeks. When stratified by age, the incidence of prescriptions of each drug class, including benzodiazepines, rose notably in young adults in recent years.

Consequences

The increase in incident prescribing for anxiety in recent years, which was most notable in young adults, may reflect better detection of anxiety and increasing acceptability of pharmacological treatment. However, some of this prescribing is not based on robust evidence of effectiveness, such as the use of beta-blockers, and there is limited evidence on the effect of taking antidepressants long-term and, as such, there may be unintended harm. Importantly, some of this prescribing may contradict guidelines, such as the prescribing of antipsychotics, and the long-term use of benzodiazepines.