Clinical Usefulness of Bright White Light Therapy for Depressive Symptoms in Cancer Survivors: Results from a Series of Personalized (N-of-1) Trials.

Ian M Kronish,Jenny Lee,Ying Kuen Cheung,Dawn L Hershman,Jerry Suls,Karina W Davidson,Faith Parsons,Jacob Julian,Paige Green,Sunmoo Yoon,Heidis Valdimarsdottir

doi:10.3390/healthcare8010010

Abstract

Purpose: Little is known about the effectiveness of bright white light therapy (BWL) for depressive symptoms in cancer survivors, many of whom prefer non-pharmacological treatments. The purpose of this study was to compare the effectiveness of BWL versus dim red light therapy (DRL) on depressive symptoms within individual cancer survivors using personalized (N-of-1) trials. Methods: Cancer survivors with at least mild depressive symptoms were randomized to one of two treatment sequences consisting of counterbalanced crossover comparisons of three-weeks of lightbox-delivered BWL (intervention) or DRL (sham) for 30 min each morning across 12 weeks. A smartphone application guided cancer survivors through the treatment sequence and facilitated data collection. Cancer survivors tracked end-of-day depressive symptoms (primary outcome) and fatigue using visual analog scales. Within-patient effects of BWL were assessed using an autoregressive model with adjustment for linear time trends. Results: Eight of nine cancer survivors completed the 12-week protocol. Two survivors reported significantly (i.e., p < 0.05) lower depressive symptoms (−1.3 ± 0.5 and −1.30 ± 0.9 points on a 10-point scale), five reported no difference in depressive symptoms, and one reported higher depressive symptoms (+1.7 ± 0.6 points) with BWL versus DRL. Eight of nine cancer survivors recommended personalized trials of BWL to others. Conclusions: There were heterogeneous effects of three-week BWL on self-reported depressive symptoms among cancer survivors, with some finding a benefit but others finding no benefit or even harm. Implications for Cancer Survivors: Personalized trials can help cancer survivors learn if BWL is helpful for improving their depressive symptoms.

Highlights

More than one in five cancer survivors has elevated depressive symptoms, three-fold the prevalence in the general population [1,2,3]
Even though evidence for their effectiveness is often lacking, complementary and alternative medicine (CAM) treatments have become increasingly popular among cancer survivors, with up to 80% of cancer survivors reporting CAM use at least once after diagnosis [10,11,12]
Recent small randomized clinical trials (RCTs) suggest that bright white light therapy (BWL) may be effective for reducing depressive symptoms and fatigue in cancer survivors [14,15,16]

Summary

Introduction

More than one in five cancer survivors has elevated depressive symptoms, three-fold the prevalence in the general population [1,2,3]. Depressive symptoms are a major contributor to poor quality of life in cancer survivors [4]. Cancer survivors with depressive symptoms are at risk of poor adherence to preventive therapies, [5,6] worse prognosis, [7,8], and higher health care costs [9]. Among CAM treatments for depressive symptoms, there is growing evidence in support of bright white light therapy (BWL) [13]. Recent small randomized clinical trials (RCTs) suggest that BWL may be effective for reducing depressive symptoms and fatigue in cancer survivors [14,15,16]. RCTs, estimate the effect of BWL for the average patient in the trial, and provide limited information on the treatment effect that an individual patient can expect to receive

Objectives

Methods

Results

Discussion

Conclusion