Incidence of SSRI treatment and psychiatric specialist care in new-onset adult epilepsy: are newer antiseizure medications associated with more treatment of anxiety/depression?

BackgroundPersons with epilepsy are at increased risk of depression/anxiety. Older antiseizure medications (ASMs) had drug-drug interactions that complicated pharmacotherapy of depression/anxiety; newer ASMs lack this drawback but can have psychiatric side effects. Anxiety/depression are increasingly recognized and treated pharmacologically. We hypothesized that the likelihood of treatment with selective serotonin uptake inhibitors (SSRI) would have increased in adult-onset epilepsy when prescription habits shifted towards newer ASMs. MethodsWe linked national health registers and included 28569 persons with epilepsy incident in 2006-2020 and 68509 age- and sex matched controls. We assessed the risk of starting SSRI treatment compared to age- and sex-matched controls across three incidence periods: 2006-2010, 2011-2015, and 2016-2020. Cox regression was used to estimate adjusted hazard ratios (HRs), and subgroup analyses explored age, sex, and comorbidities. Specialist psychiatric care was also assessed as a measure of more severe depression. Analysis including persons with SSRI-use before the epilepsy diagnosis were used for sensitivity analyses. FindingsPersons with epilepsy had higher risks of starting SSRIs compared to controls; 1986/9561 (20.8%) received SSRI during follow-up after epilepsy in 2006-2010 and 2020/9165 (22.0%) in 2016-2020; adjusted HRs were 1.92 (95%CI:1.79 - 2.06) in 2006-2010, 1.84 (95%CI:1.72-1.97) in 2011-2015, and 1.81 (95%CI:1.69 - 1.94) in 2016-2020. Among individuals aged 18-30 years at their epilepsy diagnosis, the proportion receiving SSRIs remained the same between the first and last calendar periods (18.2%). Because of increased treatment of controls, the adjusted HRs of SSRI-treatment decreased from 2.33, (95% CI:1.96 - 2.78) to 1.63, (95% CI 1.39 to 1.91). The HR of specialist psychiatric care was not significantly different between the time periods. Most comorbidities were consistently associated with increased likelihood of SSRI treatment, whereas intellectual disability decreased the likelihood in some periods. InterpretationWe found no evidence of overall increased SSRI initiation or psychiatric care after the shift to newer ASMs. Person with epilepsy remain more likely to receive SSRI treatment, but probably not to a level matching the higher prevalence of depression. Increased SSRI treatment of younger age adults has not been matched by increased treatment of young adults with epilepsy. This suggests a potentially widening treatment gap and a need for increased recognition of depression in young adults with epilepsy. FundingSwedish Research Council (2023-02816), Swedish state through the ALF-agreement (ALFGBG-1006343), Knut och Ragnvi Jacobsson foundation, Swedish Society for Medical Research (S18-0040), Swedish Society of medicine (SLS-881501), Epilepsifonden, Rune och Ulla Amlovs stiftelse.