Early discontinuation of antidepressant treatment and suicide risk among persons aged 50 and over: a population-based register study.

BACKGROUND

As many as 47% of adults over age 50 discontinue treatment with antidepressants after redeeming only one prescription. The study aim was to assess the risk of suicide in adults aged 50+ who discontinue antidepressants at an early stage of treatment.

METHOD

Case control study of all individuals aged 50+ living in Denmark and who initiated antidepressant treatment between July 1st 1995 and December 31st 2000 (N=217,123). Hazard ratios were calculated using Cox regression analyses, propensity score matching techniques, and marginal structural models.

RESULTS

During the study period, 78,594 men and 138,529 women aged 50+ began treatment with an antidepressant medication, of whom 309 men and 229 women died by suicide. Men aged 50+ who discontinued treatment early had a suicide rate of 167 per 100,000 compared with 175 per 100,000 in those who continued refilling prescriptions; hazard ratio=0.98 [CI-95%: 0.78-1.23]. The suicide rate in women who discontinued treatment was 52 per 100,000 compared with 74 per 100,000 in those who continued refilling; hazard ratio=0.72 [CI-95%: 0.55-0.94]. Although people with previous psychiatric hospitalizations had greater risk of suicide than those without past hospital admissions, the difference was not significant in the adjusted model.

LIMITATIONS

Prescriptions redeemed at pharmacies are our only indicator of treatment adherence. Also, information on severity of depression was not available.

CONCLUSIONS

We did not find a lower suicide risk among people over age 50 who seemingly follow treatment in comparison with those who discontinued treatment with antidepressants at an early stage.