Beta-blockers for exams identify students at high risk of psychiatric morbidity

OBJECTIVES: Beta-blockers relieve the autonomic symptoms of exam-related anxiety and may be beneficial in exam-related and performance anxiety, but knowledge on related psychiatric outcomes is unknown. We hypothesized that beta-blocker therapy for exam-related anxiety identifies young students at risk of later psychiatric events.

METHODS: Using Danish nationwide administrative registries, we studied healthy students aged 14-30 years (1996-2012) with a first-time claimed prescription for a beta-blocker during the exam period (May-June); students who were prescribed a beta-blocker for medical reasons were excluded. We matched these students on age, sex, and time of year to healthy and study active controls with no use of beta-blockers. Risk of incident use of antidepressants, incident use of other psychotropic medications, and suicide attempts was examined by cumulative incidence curves for unadjusted associations and multivariable cause-specific Cox proportional hazard analyses for adjusted hazard ratios (HRs).

RESULTS: We identified 12,147 healthy students with exam-related beta-blocker use and 12,147 matched healthy students with no current or prior use of beta-blockers (median age, 19 years; 80.3% women). Among all healthy students, 0.14% had a first-time prescription for a beta-blocker during the exam period with the highest proportion among students aged 19 years (0.39%). Eighty-one percent of the students filled only that single prescription for a beta-blocker during follow-up. During follow-up, 2225 (18.3%) beta-blocker users and 1400 (11.5%) nonbeta-blocker users were prescribed an antidepressant (p < 0.0001); 1225 (10.1%) beta-blocker users and 658 (5.4%) nonbeta-blocker users were prescribed a psychotropic drug (p < 0.0001); and 16 (0.13%) beta-blocker users and 6 (0.05%) nonbeta-blocker users attempted suicide (p = 0.03). Exam-related beta-blocker use was associated with an increased risk of antidepressant use (adjusted HRs, 1.68 [95% confidence intervals (CIs), 1.57-1.79], p < 0.0001), other psychotropic medication use (HR, 1.93 [95% CI, 1.76-2.12] p < 0.0001), and suicide attempts (HR, 2.67 [95% CI, 1.04-6.82] p = 0.04).

CONCLUSION: In healthy students, use of beta-blockers during the exam period was associated with an increased risk of psychiatric outcomes and might identify psychologically vulnerable students who need special attention.