Study Design

How the study is structured

FELIX is a randomized, double-blinded, placebo-controlled clinical trial. This means that neither participants nor researchers know who receives active treatment and who receives placebo.

Active group

40 Hz masked flickering light

Placebo group

Continuous light matched in color temperature and brightness

Treatment period

6 weeks of daily light therapy for 1 hour at home

Follow-up

Final visit at week 8 to assess lasting effects

What We Measure

Study endpoints and assessments

Primary endpoint

Change in depression severity measured by the Hamilton Depression Rating Scale (HAM-D6) from baseline to week 6.

Secondary endpoints

  • Self-reported depression (MDI)
  • Neurocognitive function
  • Sleep quality (PSQI)
  • Quality of life (WHO-5)
  • EEG changes

Study visits

5 visits with clinical assessments: baseline, day 7, day 21, day 42, and day 56.

Timeline

How the study unfolds

Screening

Eligibility assessment, informed consent, and baseline measurements.

1

Week 1

First follow-up visit with depression scoring and neurocognitive testing.

2

Week 3

Mid-point visit with clinical evaluation of symptoms and sleep.

3

Week 6

End of treatment. Primary endpoint measured.

4

Week 8

Follow-up visit to assess lasting effects after treatment cessation.

5