Research roundup: Using bright light therapy beyond seasonal affective disorder

This issue reviews a sampling of research related to bright light therapy and possible implications for conditions other than seasonal affective disorder.

Bright light therapy (BLT) has been demonstrated to be helpful to individuals with seasonal affective disorder. More recent research is investigating whether and how it is helpful for other problems. After reading these summaries, those interested in using BLT may want to delve into the research more completely in order to make a determination of what may be useful in their practices.

Naus, T., Burger, A., Malkoc, A., Molendijk, M., & Haffmans, J. (2013). Is there a difference in clinical efficacy of bright light therapy for different types of depression? A pilot study. Journal of Affective Disorders. Advance online publication. doi:10.1016/j.jad.2013.07.017

Summary

Using a multilevel, mixed model design, this pilot study aimed to determine whether the therapeutic benefits of bright light therapy (BLT) that have been observed in treating seasonal affective disorder (SAD) could be generalized to other mood disorders, either as an alternative or complementary to other existing treatments. Forty eight individuals diagnosed with major depressive disorder were recruited from The Department of Mood Disorders, PsyQ, The Hague, Netherlands. Twenty of these participants had melancholic features and 28 had atypical features.

Participants were new patients (prior treatment experience unknown) who first received BLT upon admission to the outpatient clinic. BLT was administered during 30-minute sessions on weekdays for up to three consecutive weeks. Participants completed the Quick Inventory of Depressive Symptoms – Self Report (WJDS – SR16) to assess the severity of their depression, and also completed the Seasonal Pattern Assessment Questionnaire (SPAQ) to assess their mood and behavior changes. Participants completed these prior to beginning their BLT sessions, after completing their BLT sessions, and then 4 weeks after their final session.

Results indicated that BLT resulted in less severe depressive symptoms, regardless of type (melancholic or atypical). Additionally, seasonality of depressive symptoms did not predict response to treatment.

Practical Implications

While BLT is often recommended for individuals with noted seasonal variations in mood difficulties, this study suggests it could possibly be an effective alternative or add-on treatment for depression regardless of its seasonal component. It also appears to benefit individuals with a variety of different symptom presentations. Psychologists may want to consider whether BLT would be a useful addition to ongoing treatment with individuals who are depressed. As with any new treatment component or modality, psychologists and their patients would be encouraged to systematically track whether the addition of BLT appeared to result in changes in symptom presentation or important outcomes.

Gordijn, M. C. M., 't Mannetje, D, & Meesters, Y. (2012). The effects of blue-enriched light treatment compared to standard light treatment in seasonal affective disorder. Journal of Affective Disorders, 136(1-2), 72-80. doi:10.1016/j.jad.2011.08.016

Summary

Using a single-blind study design, the authors compared the effects of blue-enriched light therapy with standard light therapy for patients diagnosed with seasonal affective disorder (SAD). A sample of 52 patients were selected from an initial pool of 200 for treatment at the University Medical Center Groningen in the Netherlands. Participants were current outpatients who were screened for autumn and winter depression using the Beck Depression Inventory (BDI-II, Dutch version). The 52 individuals selected for the treatment paradigm were those who scored a 15 or higher on the BDI-II-NI (40 females, 12 males, mean age of 38.8 years). Twenty eight patients had received light therapy prior to the current study, and 24 patients had not.

Participants either received two weeks of 20-minutes of blue-enriched light, 30 minutes of blue-enriched light, or 30 minutes of standard light therapy. Results indicated no significant differences between the treatment paradigms, with all three groups demonstrating similarly high treatment effects.

Practical Implications

Psychologists who recommend BLT to patients may want to explain the pros and cons of different types of light therapy in order to help their patients make decisions regarding which device to use. Given that participants in this study with blue-enriched light achieved similar results in 20-minute sessions to those who had 30-minute standard sessions, some individuals might prefer the blue-enriched light for efficiency reasons. Understanding potential pros and cons (such as possible cost differences of devices relative to efficiency) will help psychologists and patients make more informed choices regarding devices.

Reeves, G. M., Nijjar, G. V., Langenberg, P. L., Johnson, M. A., Khabazghazvini, B., Sleemi, A., Vaswani, D., Lapidus, M., Manalai, P., Tariq, M., Acharya, M., Cabassa, J., Snitker, S., & Postolache, T. T. (2012). Improvement in depression scores after 1 hour of light therapy treatment in patients with seasonal affective disorder. The Journal of Nervous and Mental Disease, 200(1), 51 - 55.

Summary

The study sought to determine whether light therapy could rapidly improve mood in participants experiencing depression due to seasonal affective disorder (SAD). Researchers recruited 79 participants from an initial pool of 925 interested applicants. Eligibility was determined through a multi-step screening process: First, the researchers assessed applicants using the Seasonal Pattern Assessment Questionnaire (SPAQ); second, a subsequent face-to-face interview assessing seasonal affective disorder presentation was conducted; third, a repeat telephone screening utilizing the SPAQ 24 hours prior to the first dose of light therapy was administered; and finally, another SPAQ measurement was completed the morning before the first dose of light therapy to rule-out brief mood fluctuation in participants.

All 79 participants were exposed to two hours of light — one hour of bright light therapy and one hour of placebo, dim red light therapy. The type of light to which participants were exposed first and second was determined through a randomized process, resulting in 41 participants receiving bright light therapy during the first hour, and the remaining 38 receiving it the second hour. Results showed that exposure to bright light therapy resulted in a modest decrease of depressive symptoms associated with SAD, as measured by the Profile of Mood States Depression-Rejection (POMS-D) and the Beck Depression Inventory (BDI).

Practical Implications

Participants experienced a modest decrease in depressive symptoms after only one hour of exposure to standard light therapy. While the data do not indicate whether this improvement was lasting, this type of modest change after just one hour may be an indicator of whether someone will find light therapy beneficial. Psychologists may wish to have a BLT device available for patients to try so that patients can determine whether BLT might have a positive effect on their depressive symptoms.

Evans, M., Rohan, K. J., Sitnikov, L., Mahon, J. N., Nillni, Y. I., Tierney Lindsey, K.,& Vacek, P. M. (2013). Cognitive change across cognitive-behavioral and light therapy treatments for seasonal affective disorder: What accounts for clinical status the next winter? Cognitive Therapy and Research. Advance online publication. doi:10.1007/s10608-013-9561-0

Summary

This study was conducted to see if participants treated with cognitive behavioral therapy, light therapy, or a combination of both experienced a change in their cognition, and if this change was related to mood outcomes the following winter. Sixty nine participants received six weeks of cognitive behavioral therapy, light therapy or combination treatment. Participants were assessed for cognitive symptoms typically associated with depression/SAD, such as dysfunctional attitudes, negative automatic thoughts and rumination.

Several trends were observed: First, regardless of treatment modality, acute treatment was associated with reduced symptoms of dysfunctional attitude, negative automatic thoughts and rumination. Second, all three groups showed improvement the following winter although the effect appeared strongest for those in the CBT only condition. Acute treatment helped improve the participants' dysfunctional attitudes, negative automatic thoughts and rumination regardless of the treatment method being used. Additional analyses demonstrated that cognitive-behavioral therapy alone revealed a relationship between fewer dysfunctional attitudes and negative, automatic thoughts, and fewer depressive symptoms the following winter.

Practical Implications: While light therapy had a positive impact on participants' symptoms of depression, cognitive-behavioral therapy appeared to have a more lasting impact the following winter on the cognitive features that contribute to depression. While light therapy is often the first choice for SAD, actively addressing underlying cognitions and challenging thoughts may lead to sustained improvements in depressed mood. Psychologists will want to evaluate the best options and combinations of treatments in order to meet the individual needs of their patients.