Evening types demonstrate reduced SSRI treatment efficacy

ABSTRACT

Selective serotonin reuptake inhibitors (SSRIs) have a profound effect on the circadian system's response to environmental light, which may impact treatment outcomes for patients depending on their habitual light exposure patterns. Here, we investigated the relationship between time-of-day preference, depressive symptoms and self-reported antidepressant treatment response. Evening types reported having taken a higher number of antidepressant medications in the previous 5 years and lower SSRI efficacy than morning types. While undergoing SSRI treatment, evening types also reported more depressive symptoms and suicidality. It is concluded that time-of-day preference may prove informative in predicting SSRI treatment responses.

KEYWORDS:

• Chronotype
• Depression
• Circadian rhythms
• Antidepressants
• Mood

Acknowledgements

EM McGlashan receives financial support from the Australian Government through a Research Training Program (RTP) Scholarship.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the data presented here, and the writing of the paper.