Table 2.
Characteristics and outcomes of personalized trials of light therapy for depressive symptoms (N = 9).
| Patient | Season (Months) | Treatment Sequence | Percent of Days with Symptom Assessments | Mean Depressive Symptoms (0, None to 10, Severe) |
Mean Fatigue Symptoms (0, None to 10, Severe) |
Treatment Preference at end of Trial | Likelihood of Continuing Light Therapy (Not at All to Very Much) |
Helpfulness of Participation (Not at All to Very Much) |
Recommend to Others (Not at All to Very Much) |
|---|---|---|---|---|---|---|---|---|---|
| 1 (7702) |
Fall (September-December) |
W-R-R-W | 19% | Insufficient | Insufficient | Neither | Not at all likely to continue | Not at all helpful | Recommend a little bit |
| 2 (7703) | Fall (September-December) |
R-W-W-R | 62% † | R: 5.9 W: 6.7 Difference: 0.7 SE 0.8, p = 0.40 |
R: 7.0 W: 8.2 Difference: 1.3 SE 0.5, p = 0.001 |
R | Somewhat likely to continue | Somewhat helpful | Recommend a little bit |
| 3 (7705) |
Fall (October–January) |
W-R-R-W | 80% | R: 3.6 W: 5.1 Difference: 1.3 SE 0.6, p = 0.04 |
R: 4.7 W: 5.7 Difference: 0.9 SE 0.7, p = 0.17 |
R | Somewhat likely to continue | Very much helpful | Recommend strongly |
| 4 (7706) |
Fall (November–January) |
W-R-R-W | 64% | R: 2.6 W: 2.8 Difference: −0.01 SE 0.3, p = 0.98 |
R: 2.6 W: 2.6 Difference: −0.2 SE 0.2, p = 0.43 |
Neither | Not at all likely to continue | Not at all helpful | Recommend not at all |
| 5 7707 |
Fall (November–January) |
R-W-W-R | 66% | R: 3.0 W: 1.8 Difference: −1.3 SE 0.5, p = 0.005 |
R: 3.8 W: 3.7 Difference: −0.3 SE 0.5, p = 0.59 |
W | Very likely to continue | Very much helpful | Recommend strongly |
| 6 7708 |
Winter (November–February) | W-R-R-W | 57% | R: 3.0 W: 1.3 Difference: −1.3 SE 0.9, p = 0.17 |
R: 4.6 W: 2.9 Difference: −1.7 SE 0.7, p = 0.03 |
W | Very likely to continue | Very much helpful | Recommend strongly |
| 7 7709 |
Winter (December–March) | W-R-R-W | 64% | R: 3.6 W: 4.0 Difference: 0.3 SE 1.0, p = 0.74 |
R: 4.8 W: 6.0 Difference: 0.6 SE 1.0, p = 0.55 |
W | Very likely to continue | Very much helpful | Recommend strongly |
| 8 7710 |
Spring (March–June) | W-R-R-W | 77% | R: 2.2 W: 3.0 Difference: 0.7 SE 0.7, p = 0.32 |
R: 3.1 W: 3.4 Difference: 0.3 SE 0.6, p = 0.60 |
Either | Unlikely to continue | Somewhat helpful | Recommend strongly |
| 9 7713 |
Spring (April–June) | R-W-W-R | 89% | R: 1.1 W: 1.0 Difference: −0.1 SE 0.1, p = 0.51 |
R: 7.3 W: 7.1 Difference: −0.2 SE 0.4, p = 0.65 |
Either | Unlikely to continue | A little bit helpful | Recommend strongly |
Abbreviations: W, bright white light therapy; R, dim red light therapy; SE, standard error. Depressive and fatigue symptoms were assessed at the end of each day on a scale from 0 (none) to 10 (severe). † Assessments were interrupted in the middle third of the study due to an interruption in the smartphone application.