Switches and early discontinuations of antidepressant medication in young adults with depression.

Background: Receiving treatment for depression is increasingly common among young adults. Antidepressants (AD) are important in depression treatment and modification of medication is common. We examined switches and discontinuations of ADs among young Finnish adults aged 18-29 years.

Methods: All persons diagnosed with depression in inpatient or specialized outpatient care or having received sickness absence or disability pension due to depression at age of 18-29 years during 2004-17 were included (N = 110761). Among them, we focused on incident AD users (N = 52855, 47.7%) who were identified with a 6 month washout before AD initiation. The follow-up was 2 years.

Results: The majority (76.3%) initiated with selective serotonin reuptake inhibitors (SSRIs). The initial AD was switched in 17.4% of cases. Switching was most common when treatment was initiated with tricyclic antidepressants (TCA) or polytherapy, and least common when initiated with SSRIs or serotonin-noradrenaline reuptake inhibitors. Factors associated with switch included initiation with polytherapy, TCA or mirtazapine, and use of benzodiazepines or Z-drugs at baseline. During the first 3 months, 27.6% discontinued AD use, and only 14.1% used AD for 2 years. Factors associated with discontinuation included substance abuse, ADHD, previous suicide attempt and initiation with mirtazapine. SSRIs had the longest time to discontinuation (median 144 days, IQR 64-302).

Limitations: Our data sources lack those treated in primary care only, without receiving a sick leave of ≥2 weeks. In addition, we do not have data on severity of depression, social factors or psychotherapy.

Conclusions: Special emphasis should be paid to persons with increased risk of discontinuation, including those with previous self-harm/suicide attempt or substance abuse.