The effects of ultraviolet-A wavelengths in light therapy for seasonal depression

Indoor tanning: Evidence surrounding advertised health claims

Indoor tanning continues to remain common, despite evidence of an increased risk of skin cancer from artificial ultraviolet (UV) radiation. In the hopes of gaining customers, the tanning bed industry has marketed health benefits of indoor tanning such as increased vitamin D production, development of a base tan, enhanced mood, and treatment of certain dermatologic conditions. To better educate their patients, providers need a comprehensive reference reviewing the evidence that support or oppose these claims. In this work, we conducted an evidence-based review of the literature to identify and grade studies that investigate health claims related to UV exposure. Results indicate that there is little evidence to support each of these proposed health benefits. Tanning beds emit primarily UVA radiation, which is relatively ineffective at activating vitamin D or mood enhancing pathways, and the effects are minimal in regard to tanning beds generating a protective base tan or treating dermatologic conditions compared with the increased risk of skin cancer. Health care providers must continue to warn and educate patients about the misleading information propagated by the tanning bed industry as well as about the dangers of artificial UV radiation.

Light therapy: is it safe for the eyes?

OBJECTIVE

Light therapy has become an increasingly popular treatment for depression and a range of other neuropsychiatric conditions. Yet, concerns have been raised about the ocular safety of light therapy.

METHOD

We conducted the first systematic review into the ocular safety of light therapy. A PubMed search on January 4, 2017, identified 6708 articles, of which 161 were full-text reviewed. In total, 43 articles reporting on ocular complaints and ocular examinations were included in the analyses.

RESULTS

Ocular complaints, including ocular discomfort and vision problems, were reported in about 0% to 45% of the participants of studies involving light therapy. Based on individual studies, no evident relationship between the occurrence of complaints and light therapy dose was found. There was no evidence for ocular damage due to light therapy, with the exception of one case report that documented the development of a maculopathy in a person treated with the photosensitizing antidepressant clomipramine.

CONCLUSION

Results suggest that light therapy is safe for the eyes in physically healthy, unmedicated persons. The ocular safety of light therapy in persons with preexisting ocular abnormalities or increased photosensitivity warrants further study. However, theoretical considerations do not substantiate stringent ocular safety-related contraindications for light therapy.

Daylight exposure and the other predictors of burnout among nurses in a University Hospital

The purpose of the study was to investigate if daylight exposure in work setting could be placed among the predictors of job burnout. The sample was composed of 141 nurses who work in Akdeniz University Hospital in Antalya, Turkey. All participants were asked to complete a personal data collection form, the Maslach Burnout Inventory, the Work Related Strain Inventory and the Work Satisfaction Questionnaire to collect data about their burnout, work-related stress (WRS) and job satisfaction (JS) levels in addition to personal characteristics. Descriptive statistics, parametric and non-parametric tests and correlation analysis were used in statistical analyses. Daylight exposure showed no direct effect on burnout but it was indirectly effective via WRS and JS. Exposure to daylight at least 3h a day was found to cause less stress and higher satisfaction at work. Suffering from sleep disorders, younger age, job-related health problems and educational level were found to have total or partial direct effects on burnout. Night shifts may lead to burnout via work related strain and working in inpatient services and dissatisfaction with annual income may be effective via job dissatisfaction. This study confirmed some established predictors of burnout and provided data on an unexplored area. Daylight exposure may be effective on job burnout.

Perspectives in melanoma prevention: the case of sunbeds

The incidence of cutaneous malignant melanoma (melanoma) and of basal cell carcinoma is still increasing in most fair-skinned populations. The fashion of intermittent exposure to solar ultraviolet (UV) radiations is considered the main cause of this increase. In 20 years time, tan acquisition through exposure to artificial sources of UV radiations has become frequent among fair-skinned adolescents and young adults. Modern sunbeds are powerful sources of UV radiations that do not exist in the nature, and repeated exposures to high doses of UVA constitute a new phenomenon in humans. A large prospective cohort study on 106,379 Norwegian and Swedish women conducted between 1991 and 1999 has provided evidence for a significant, moderate increase in melanoma risk among regular sunbed users. Failure of past case-control studies to document with consistency the sunbed-melanoma association was probably due to a too short latency period between sunbed use and melanoma diagnosis, and to too few subjects with high total durations of sunbed use. Regulations of sunbed installation, operation and use should become standardised across the 25 European Union countries. Enforcement of regulations in tanning parlours remains inadequate. In contrast, the existence of regulations is presented by many tanning salon operators as a guarantee that sunbed use is safe. We stress the need for the control of information disseminated by the "tanning industry" on suppositions that sunbed use is safer than sun exposure, and on the hypothetical health benefits of tanning. New fluorescent UV lamps are proposed that have a spectrum similar to the midday sun. Given the known association between intermittent sun exposure and melanoma, public-health authorities should reconsider the soundness of the commercialisation of these lamps.

Light treatment of mood disorders

In 1981, seven patients with nonseasonal depression were treated with bright white light in 1982, bright artificial light was used to treat a manic-depressive patient with a seasonal mood cycle. In the last 20 years, a plethora of studies have further defined the depressive populations, who are responsive to light treatment; the optimal timing, intensity, spectral frequency, and duration of treatment; its comparison with other pharmacological interventions; predictors of response; side-effect profiles; viable placebo-control conditions; alternative devices and forms of administration; potential mechanisms and anatomical pathways mediating light's physiological effects; and its application to other disorders and subsyndromaI states. These studies have been conducted across multiple countries with surprisingly consistent results. Further work is needed, as highlighted in this review, to clarify the specific mechanism of action in subtypes of depressive disorders and differential age and gender effects. Although the majority of work in this area is relatively new, it behooves the reader to remember that Solomon, almost 3000 years ago, wrote in Ecclesiastes: "Truly the light is sweet and a pleasant thing it is for the eyes to behold the sun" (11:7).

Bright light treatment decreases depression in institutionalized older adults: a placebo-controlled crossover study

BACKGROUND

An important parallel exists between patients with seasonal affective disorder and institutionalized older adults. Many older patients, as a result of global physical decline and immobility, are confined to their rooms, experiencing little natural sunlight. Thus, institutionalized older adults are at risk for chronic light deprivation. Testing the hypothesis that chronic light deprivation might be responsible, at least in part, for some depression among institutionalized older adults, the aim of this study was to investigate the efficacy of morning bright light treatment on depression among older adults residing in a long-term care facility.

METHODS

In a placebo controlled, crossover design, participants (N = 10, six women and four men; M age = 83.8) received each of the following: (i) 1 week (5 days) of 10,000 lux (therapeutic dose); (ii) 1 week (5 days) of 300 lux (placebo); or 1 week of no treatment (control). Each week of light treatment was 5 consecutive days, 30 minutes daily, with a wash-out period consisting of 1 week between conditions.

RESULTS

Geriatric Depression Scale (GDS) scores at baseline during all treatment conditions were positively correlated (r = .81, p < .01) with months of institutionalization, where participants with higher GDS scores experienced more time institutionalized. Scores on the GDS remained unchanged during the placebo and control conditions, but depression scores decreased significantly during the 10,000 lux treatment (pretest GDS M = 15 vs posttest GDS M = 11, p < .01). After the 10,000 lux treatment, 50% of the participants no longer scored in the depressed range. Improvement during the 10,000 lux condition was positively correlated (r = .62, p < .05) to baseline GDS scores, where participants with higher GDS scores experienced greater improvement following the 10,000 lux treatment.

CONCLUSIONS

The results of the present study suggest that bright light treatment may be effective among institutionalized older adults, providing nonpharmacological intervention in the treatment of depression. Furthermore, the length of institutionalization may play an important role in determining the efficacy of bright light treatment for older adults in the nursing-home setting.

Prophylactic treatment of seasonal affective disorder (SAD) by using light visors: bright white or infrared light?

BACKGROUND

Thirty-eight patients with SAD participated in a light visor study addressing two questions. 1. Can the development of a depressive episode be prevented by daily exposure to bright light started before symptom onset in early fall and continued throughout the winter? 2. Does the light have to be visible in order to have beneficial effects?

METHODS

Three groups participated in the study: I (n = 14) received bright white light (2500 lux); II, (n = 15) received infrared light (0.18 lux); III (n = 9, control group) did not receive any light treatment at all.

RESULTS

Infrared light is just as effective as bright white light. Both are more effective than the control condition.

CONCLUSIONS

Light visors can be effectively used to prevent the development of SAD. The fact that exposure to infrared light was as effective as exposure to bright white light questions the specific role of visible light in the treatment of SAD.

Dose-response relationship of phototherapy for seasonal affective disorder: a meta-analysis

OBJECTIVE

The therapeutic effect of phototherapy for seasonal affective disorder (SAD) has been widely investigated. However, the antidepressant effect of various light intensities is inconclusive. The purpose of this study was to evaluate the dose-response relationship of phototherapy for SAD.

METHOD

A meta-analytical methodology was applied to 39 studies of phototherapy for SAD. The studies collected were screened for study quality by a threats-to-validity method before inclusion. The fixed-effects-model analysis of variance procedures were used for data analysis.

RESULTS

The results indicated that different light intensities produced different effects in reducing the typical symptoms, as measured by the Hamilton Depression Rating Scale, of patients with SAD. However, no significant differences in these effects were revealed between strong, medium and dim light in reducing the atypical symptoms of patients.

CONCLUSION

These findings showed that light intensity varied positively with the antidepressant effect for typical but not for atypical symptoms of SAD, suggesting that light intensity tended to have different therapeutic effects on the typical and atypical symptoms of SAD.

Pathophysiological mechanism of seasonal affective disorder

Despite the long history in medicine, the pathophysiological mechanism(s) of seasonal affective disorder (SAD) remain largely unknown. By employing a meta-analytic methodology, the authors of this study attempted to verify the validity of different pathophysiological mechanism(s) proposed for SAD. The findings showed that for phototherapy of medium light intensity, a combination of morning-evening therapy regime yielded the best therapeutic effect, and the antidepressant effect of the morning-evening light regime was superior to a single pulse of light administered at other times of day. Furthermore, the data showed that the antidepressant effect of a single pulse of light was similar for morning, midday, and evening light. These findings supported the photon-count hypothesis and refuted the proposed photoperiod, melatonin, and phase-shifting models of SAD.

Spectral properties of phototherapy for seasonal affective disorder: a meta-analysis

The general therapeutic effect of light on seasonal affective disorder (SAD) has been widely acknowledged. However, the antidepressant effect of light does not seem to be the same for different spectra of light. In this study, the authors attempted to study the spectral properties of phototherapy for SAD using a meta-analytical procedure. The findings suggested that light of short to medium wavelengths (blue/green/yellow) seem to be essential for the therapeutic effect of light on SAD. Red wavelengths were relatively ineffective. It was then postulated that SAD may be predisposed and/or precipitated by the inefficiency of the S and M cones in the retina. Furthermore, ultraviolet (UV) waves did not seem to be essential for SAD symptom alleviation by artificial light. Therefore, these potentially harmful UV waves should be blocked in any clinical application of phototherapy for SAD.

Treatment of seasonal affective disorder: a review

OBJECTIVE

To review the status of current treatment of seasonal affective disorder (SAD).

METHOD

Treatment studies of SAD published between January 1989 and March 1995 were identified using a computerized MEDLINE literature search. Additional citations were obtained from the reference sections of these articles. Studies included in this review were selected using operational methodologic criteria.

RESULTS

Many studies support the efficacy of bright light therapy using a fluorescent light box. The best studied protocol is > 2500 lux white light for 2 hours per day, but newer protocols using 10,000 lux for 30 minutes have comparable response rates. Studies of light visors and other head-mounted devices also report similar response rates, but have not yet shown superiority over putative control conditions. There are fewer medication studies in SAD, but controlled studies suggest that fluoxetine, d-fenfluramine and propranolol are effective. Other treatments such as dawn simulation require further study. No studies of psychological treatments for SAD were found. Many studies had methodologic limitations, including brief treatment periods, small sample sizes, and lack of replication, that limit the generalizability of findings.

CONCLUSION

There are several well-studied, effective treatments for SAD, including light therapy and medications. However, further research must be done to demonstrate sustained treatment response over time, to clarify the intensity-response relationship of light therapy, to clarify the role of light therapy and medications, and to assess combination treatments.

Light treatment for seasonal affective disorder: theoretical considerations and clinical implications

The concept of seasonal affective disorder (SAD) includes any depression whose onset is related to a certain season. Reduced environmental light is hypothesized to be the main precipitating factor of winter depression. Light treatment is used to prevent the onset of depressive episodes and to reduce depressive symptoms in patients with depression during winter months. The mechanisms of action which lead to the well-documented antidepressant response are still unknown. Several hypotheses of the pathogenesis of SAD are discussed, and the clinical practice of light treatment is reviewed.