Mood and behavioral effects of four-week light treatment in winter depressives and controls

Adjunctive bright light therapy for treating bipolar depression: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

Bright light therapy (BLT) was reported as an effective adjunctive treatment option for bipolar disorder. Previous meta-analytic study showed that augmentation treatment with light therapy significantly decreased the severity of bipolar depression. However, most of included studies were case-control studies and several of them focused on BLT that was provided in combination with sleep deprivation therapy.

METHODS

In this meta-analysis, we used several electronic databases to search the studies and included only randomized controlled trial (RCT) studies to compare BLT with control experimental groups for treating bipolar depression with pharmacological treatment to clarify the adjunctive efficacy of BLT. We searched the databases of EMBASE, MEDLINE, Scopus, The Cochrane Central Register of Controlled Trials, the Cumulative Index to Nursing and Allied Health Literature, and Clinicaltrials.gov for studies published in English until September 19, 2019. Two researchers conducted the literature screening, data extraction, and methodological quality assessment independently. The main outcome was the response rate and remission rate. We used the Review Manager 5.3 Software for the meta-analysis.

RESULTS

Four trials with a total of 190 participants (intervention: 94, control: 96) with bipolar depression were evaluated to gauge the effects of light therapy. The meta-analysis showed risk ratios of 1.78 (95% CI 1.24-2.56, p = .002; I2  = 17%) demonstrating a significant effect of light therapy in the response rate of bipolar disorder. The meta-analysis shows risk ratios of 2.03 (95% CI 0.48-8.59, p = .34; I2  = 67%) demonstrating no significant effect of light therapy in the remission rate of patients with bipolar disorder. None of the articles reported any serious adverse effects. Manic switch rate was 1.1% in the light therapy group and 1.2% in the control group.

CONCLUSIONS

Bright light therapy is an effective treatment for reducing depression symptoms among patients with bipolar depression.

Use of "Lights" for Bipolar Depression

PURPOSE

In this review, we will review the background and diagnosis of bipolar disorder (BD); describe the efficacy data and potential circadian and neural mechanisms underlying the effects of bright light for bipolar depression; and discuss the implementation of light therapy in clinical practice.

RECENT FINDINGS

To date, morning bright light is the most widely tested form of light therapy for all mood disorders. Clinical trial reports suggest that midday or morning bright light treatment and novel chronotherapeutic interventions are effective for bipolar depression. Mechanisms of response may relate to effects on the circadian system and other changes in neural functioning. Using bright light to manage depressive symptoms in BD is reasonable but also requires concurrent antimanic treatment and careful clinical monitoring for response, safety, and mood polarity switch.

Rate of switch from bipolar depression into mania after morning light therapy: A historical review

Light therapy (LT) is efficacious for bipolar depression with effect sizes equivalent to those in antidepressant pharmacotherapy trials. Patients with bipolar disorder (BD) show a 15-40% rate of manic switches during antidepressant drug treatment. The rate of manic switches during LT has never been estimated. We searched all the literature studies reporting effects of antidepressant LT in BD. 41 studies described 799 patients with BD treated with antidepressant LT, from among which 7 (0.9%) switched into mania and 11 (1.4%) switched into hypomania. The method of assessment of treatment-emergent symptoms significantly influenced the detection of switches into mania: 0% when no method was reported, 0.8% with clinical mental state examination, and 3% with rating scales (χ² = 14.805, d.f. 4, p = 0.005). The rate of switch increased to 18.8% when considering the 16 patients with rapid-cycling BD. Switches occurred independent of treatment modality (light intensity, duration, and circadian timing of administration). The available literature shows that the highest reported rate of switch from bipolar depression into mania after LT is closely similar to the 4% switch rate expected during the placebo treatment of BD, thus not justifying specific concerns when using this treatment option.

Seasonal Variation in Bright Daylight Exposure, Mood and Behavior among a Group of Office Workers in Sweden

The purpose of the study was to investigate seasonal variation in mood and behavior among a group of office workers in Sweden (56°N). Thirty subjects participated in this longitudinal study. The subjects kept a weekly log that included questionnaires for ratings of psychological wellbeing and daily sleep-activity diaries where they also noted time spent outdoors. The lighting conditions in the offices were subjectively evaluated during one day, five times over the year. There was a seasonal variation in positive affect and in sleep-activity behavior. Across the year, there was a large variation in the total time spent outdoors in daylight. The subjects reported seasonal variation concerning the pleasantness, variation and strength of the light in the offices and regarding the visibility in the rooms. Finally, the subjects spent most of their time indoors, relying on artificial lighting, which demonstrates the importance of the lighting quality in indoor environments.

Smart environment architecture for emotion detection and regulation

This paper introduces an architecture as a proof-of-concept for emotion detection and regulation in smart health environments. The aim of the proposal is to detect the patient's emotional state by analysing his/her physiological signals, facial expression and behaviour. Then, the system provides the best-tailored actions in the environment to regulate these emotions towards a positive mood when possible. The current state-of-the-art in emotion regulation through music and colour/light is implemented with the final goal of enhancing the quality of life and care of the subject. The paper describes the three main parts of the architecture, namely "Emotion Detection", "Emotion Regulation" and "Emotion Feedback Control". "Emotion Detection" works with the data captured from the patient, whereas "Emotion Regulation" offers him/her different musical pieces and colour/light settings. "Emotion Feedback Control" performs as a feedback control loop to assess the effect of emotion regulation over emotion detection. We are currently testing the overall architecture and the intervention in real environments to achieve our final goal.

Light therapy in the treatment of patients with bipolar depression: A meta-analytic study

Light therapy (LT) has been widely used in the treatment of seasonal affective disorder. Recently some evidence indicated that LT may play a role in bipolar depression, either as monotherapy or in combination with total sleep deprivation (TSD). However, the studies examining the treatment effect of LT in bipolar depression resulted in inconsistent findings. To clarify the role of LT in the disorder, we conducted a meta-analysis to compare the efficacy of LT in the treatment of bipolar depression. The results of individual studies were synthesized by a random effects model. Nine studies including 489 patients with bipolar depression were included in this current meta-analysis. We found that disease severity was significantly decreased after LT, in both with and without TSD, and with concomitant medication (p<0.001). Augmentation treatment with LT significantly decreased disease severity compared to treatment without LT (p=0.024). Our results highlight the significant efficacy of LT, either as monotherapy or in combination with TSD, in the treatment of bipolar depression. However, the detailed mechanism of LT still remains elusive. Further well-designed controlled trials are required to investigate the optimal intensity and frequency of LT in the treatment of bipolar depression.

Seasonal affective disorder: is there light at the end of the tunnel?

Seasonal affective disorder, which is underdiagnosed in the primary care setting, is a mood disorder subtype characterized by episodic major depression that typically develops in winter when daylight hours are short. Patients with SAD experience increased morbidity and decreased quality of life. This article focuses on recognition and management of this condition. Light therapy is the preferred treatment for SAD because it is safe and easy to administer; light therapy may be combined with pharmacologic therapy. Cognitive behavioral therapy (CBT) also has a positive therapeutic effect when combined with light therapy and may help prevent SAD in subsequent seasons.

The influence of light administration on interpersonal behavior and affect in people with mild to moderate seasonality

Bright light is used to treat winter depression and may also have positive effects on mood in some healthy individuals. However, there is little information on how bright light treatment influences social behavior. We performed a cross-over study in winter comparing the effects of morning bright light administration with placebo (exposure to negative ions) on mood and social behavior in 38 healthy people with mild to moderate seasonality. Each treatment was given for 21days with a washout period of 14days between treatments. An event-contingent recording assessment was used to measure mood, and social behavior along two axes, agreeable-quarrelsome and dominant-submissive, during each 21-day treatment period. During treatments, participants wore a combined light-sensor and accelerometer to test this method for adherence to light treatment self-administered at home. Data were analyzed using multilevel modeling. Bright light improved mood but increased quarrelsome behavior and decreased submissiveness. Data from the light monitor and accelerometer suggested that 21% of the participants did not adhere to bright light treatment; when this group was analyzed separately, there was no change in quarrelsomeness or mood. However, results for individuals who followed the procedure were similar to those reported for the whole sample.

Exposure to bright light is associated with positive social interaction and good mood over short time periods: A naturalistic study in mildly seasonal people

Bright light is used to treat winter depression and might also have positive effects on mood in some healthy individuals. We examined possible links between bright light exposure and social interaction using naturalistic data. For 20 days in winter and/or summer, 48 mildly seasonal healthy individuals wore a light meter at the wrist and recorded in real-time their behaviours, mood, and perceptions of others during social interactions. Possible short-term effects of bright light were examined using the number of minutes, within any given morning, afternoon or evening, that people were exposed to light exceeding 1000 lux (average: 19.6min). Social interactions were labelled as having occurred under conditions of no, low or high bright light exposure. Independent of season, day, time, and location, participants reported less quarrelsome behaviours, more agreeable behaviours and better mood when exposed to high but not low levels of bright light. Given that the effects were seen only when exposure levels were above average, a minimum level of bright light may be necessary for its positive effects to occur. Daily exposure levels were generally low in both winter and summer. Spending more time outdoors and improving indoor lighting may help optimize everyday social behaviour and mood across seasons in people with mild seasonality.

Bright light exposure during acute tryptophan depletion prevents a lowering of mood in mildly seasonal women

We investigated the influence of bright light exposure on the mood-lowering effect of acute tryptophan depletion (ATD). Mildly seasonal healthy young women without a personal or family history of psychiatric disorders remained in either dim or bright light during two test days. Tryptophan-deficient and nutritionally balanced amino acid mixtures were administered in counterbalanced order. Mood state was assessed using the Profile of Mood States (POMS) and Visual Analogue Scales (VAS). In dim light, ATD decreased POMS scores across most subscales, indicating a worsening of mood. In bright light, mood was unaffected by ATD. Thus, bright light blocked the worsening of mood caused by ATD. This was also observed on the positive mood VAS. These results indicate a direct, immediate interaction between bright light and serotonin function. Bright light might help protect against ATD-induced mood change by increasing serotonin above the threshold level below which there is a lowering of mood.

A controlled trial of the Litebook light-emitting diode (LED) light therapy device for treatment of Seasonal Affective Disorder (SAD)

BACKGROUND

Recent research has emphasized that the human circadian rhythm system is differentially sensitive to short wavelength light. Light treatment devices using efficient light-emitting diodes (LEDs) whose output is relatively concentrated in short wavelengths may enable a more convenient effective therapy for Seasonal Affective Disorder (SAD).

METHODS

The efficacy of a LED light therapy device in the treatment of SAD was tested in a randomized, double-blind, placebo-controlled, multi-center trial. Participants aged 18 to 65 with SAD (DSM-IV major depression with seasonal pattern) were seen at Baseline and Randomization visits separated by 1 week, and after 1, 2, 3 and 4 weeks of treatment. Hamilton Depression Rating Scale scores (SIGH-SAD) were obtained at each visit. Participants with SIGH-SAD of 20 or greater at Baseline and Randomization visits were randomized to active or control treatment: exposure to the Litebook LED treatment device (The Litebook Company Ltd., Alberta, Canada) which delivers 1,350 lux white light (with spectral emission peaks at 464 nm and 564 nm) at a distance of 20 inches or to an inactivated negative ion generator at a distance of 20 inches, for 30 minutes a day upon awakening and prior to 8 A.M.

RESULTS

Of the 26 participants randomized, 23 completed the trial. Mean group SIGH-SAD scores did not differ significantly at randomization. At trial end, the proportions of participants in remission (SIGH-SAD less than 9) were significantly greater (Fisher's exact test), and SIGH-SAD scores, as percent individual score at randomization, were significantly lower (t-test), with active treatment than with control, both in an intent-to-treat analysis and an observed cases analysis. A longitudinal repeated measures ANOVA analysis of SIGH-SAD scores also indicated a significant interaction of time and treatment, showing superiority of the Litebook over the placebo condition.

CONCLUSION

The results of this pilot study support the hypothesis that light therapy with the Litebook is an effective treatment for SAD.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT00139997.

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 improves vitality and alleviates distress in healthy people

BACKGROUND

The relative shortage of light during the decreasing photoperiod may compromise well-being. Earlier studies suggest that bright-light exposure may be of help to alleviate winter-bound symptoms.

METHODS

We carried out a field study with exposure to bright light on office employees during winter.

RESULTS

Repeated bright-light exposure improved vitality and reduced depressive symptoms. The benefit was observed not only in healthy subjects with season-dependent symptoms but also in those not having the seasonal variation.

CONCLUSIONS

Bright-light exposure during winter appears to be effective at improving the health-related quality of life and alleviating distress in healthy subjects.

CLINICAL IMPLICATIONS

Administration of bright light is a useful option to improve vitality and mood among subjects working indoors in wintertime. LIMITATIONS OF STUDY: Our field setting used self-reports, not interviews, for the assessment of outcome.

Dawn simulation vs. lightbox treatment in winter depression: a comparative study

Dawn simulation, with gradually increasing bedside light in the morning, has shown promising results as an alternative to bright light treatment for winter depression. To compare these treatments, 61 out-patients with winter depression (20-70 years of age, 80% women) were randomized to receive either lightbox treatment with 1500-2500 lux white light for 2 h in the morning for 6 days on an out-patient basis (n=34), or dawn simulation treatment in their homes, with 60 or 90 min of light augmentation time to 100-300 lux, for 2 weeks (n=27). Patients' ratings of improvement on a visual analogue scale (correlating strongly with percentage reduction in an extended Montgomery-Asberg Depression Rating Scale (MADRS) score) at the end of treatment showed a mean of 40.0% (SD 27.7%) in the dawn simulation group and 57.4% (SD 29.9%) in the lightbox group (P=0.02). The majority of the patients in both groups maintained their improvement during a 9-week follow-up. Age, sex, current major depression or current use of antidepressants did not predict outcome in either group. No serious side-effects were observed.

Testing the hypothesis of a circadian phase disturbance underlying depressive mood in nonseasonal depression

In a crossover design, 8 nonseasonal depressed subjects, selected on the presence of diurnal mood variations, and 8 sex- and age-matched controls were exposed to dim light (< 10 lux) in the evening (18:00-21:00 h) and bright light (2500 lux) in the morning (ML, 6:00-9:00 h), to dim light in the morning and bright light in the evening (EL), or to dim light both in the evening and in the morning (DL) during 3 consecutive days in each of these conditions. There were no initial phase differences between depressed and healthy subjects in the timing of dim light melatonin onset, sleep termination, and body temperature. The phase shifts after EL and ML in both healthy and depressed subjects were as expected on the basis of a human phase response curve. On average, there was no therapeutic effect of the light exposure in the depressed patients. Two patients improved, but these effects do not seem to be related to shifts in the circadian system.

Suppression of melatonin secretion by bright light in seasonal affective disorder

Eleven patients with winter seasonal affective disorder and 10 healthy controls were exposed to light of 3300 lux for 5 min and for 1 hour respectively on consecutive evenings at 22:00 hours during winter and summer. In the winter, the measurements were undertaken both before and after the treatment with bright light for 2 weeks. In the summer, there was no treatment. Melatonin concentration in saliva and subjective sleepiness were measured at 22:00 and 23:00 hours on each test. There was no significant difference in the suppression of melatonin in response to the light tests between the patients and the controls. Exposure to light reduced the level of subjective sleepiness more among the patients compared to the control subjects. This reduction was not associated with the change in melatonin secretion nor the improvement in depressive symptoms.

L-tryptophan augmentation of light therapy in patients with seasonal affective disorder

OBJECTIVE

Up to one-third of patients with seasonal affective disorder (SAD) do not have a full response to light therapy. Given the evidence for serotonergic dysregulation in SAD, we examined the possible role of l-tryptophan as an augmentation strategy for nonresponders and partial responders to light therapy.

METHOD

Eligible drug-free patients meeting DSM-IV criteria for SAD were treated for 2 weeks using a standard morning light therapy regimen (10,000 lux cool-white fluorescent light for 30 minutes). Partial and nonresponders were treated for 2 weeks with open-label l-tryptophan (1 g 3 times daily) while light therapy was continued. Ratings at baseline and follow-up included the 29-item Structured Interview Guide for the Hamilton Depression Rating Scale, SAD version (SIGH-SAD) and the Clinical Global Impression (CGI) scale.

RESULTS

Sixteen patients began the l-tryptophan augmentation phase. Two patients discontinued medications within 3 days because of side effects. In the 14 patients completing treatment, the addition of l-tryptophan resulted in significant reduction of mean depression scores. Nine of 14 patients (64%) showed very good clinical responses to combined treatment and minimal side effects.

CONCLUSION

This open-label study suggests that l-tryptophan may be an effective augmentation strategy for those patients with SAD who show limited or poor response to bright ligh therapy. Further placebo-controlled studies are warranted to demonstrate efficacy.

Seasonal changes in affective state measured prospectively and retrospectively

BACKGROUND

The study was designed to investigate whether seasonal mood and behavioural changes are detectable prospectively in a non-clinical population in the way they have been reported in retrospective studies. The specificity of any seasonal fluctuation in affective state was also investigated by measuring anxiety as well as depression.

METHOD

To measure seasonal fluctuations in affect and behaviour prospectively, 25 women were interviewed every month for one year using four scales (depression, anxiety, stress, and behavioural change). Retrospective accounts of mood and behaviour at the end of the year were collected with the Seasonal Pattern and Assessment Questionnaire (SPAQ).

RESULTS

Seasonal depression peaked in winter as did atypical behaviour when measured either prospectively or retrospectively, but the difference between winter and summer was much more pronounced in the retrospective data. No seasonal effect was found for anxiety or psychosocial stressors.

CONCLUSIONS

The results obtained by retrospective techniques have limited reliability. In the future, more prospective studies with unbiased, standardised instruments are recommended to measure seasonal variations in affect and behaviour.

'Natural' light treatment of seasonal affective disorder

Patients with seasonal affective disorder (SAD) were treated for 1 week either with a daily 1-h morning walk outdoors (natural light) or low-dose artificial light (0.5 h@2800 lux). The latter treatment (given under double-blind conditions) can be considered mainly placebo and did not improve any of the depression self-ratings, whereas natural light exposure improved all self-ratings. According to the Hamilton depression score, 25% remitted after low-dose artificial light and 50% after the walk. Sleep duration or timing were not crucial for the therapeutic response. The morning walk phase-advanced the onset and/or offset of salivary melatonin secretion, but individual clinical improvement could not be correlated with specific phase-shifts. Morning cortisol was decreased. Low-dose artificial light did not modify melatonin or cortisol patterns. This is the first study to provide evidence for the use of outdoor light exposure as a potential alternative or adjuvant to conventional artificial light therapy in SAD.

Influence of phototherapy treatment duration for seasonal affective disorder: outcome at one vs. two weeks

Most previous phototherapy research has been conducted on trials of 1 week duration. This study compares response to phototherapy at weeks 1 and 2. All subjects (n = 26) were between 18 and 65 years and met Diagnostic and Statistical Manual of Mental Disorders, 3rd ed, revised, (DSM III-R) criteria for major depression, recurrent, seasonal pattern and had a Hamilton Depression Rating Scale score (HAM-D) > or = 20. A rater blinded to treatment schedule and study hypothesis repeated the HAM-D-31 1 and 2 weeks after baseline to assess treatment response to bright light. Response rates at week 1 defined by 50% reduction in HAM-D-31 and HAM-D-31 score < 8 were 62% and 27%, respectively. At week 2, however, 65% had a 50% reduction in HAM-D-31 and 62% had a HAM-D-31 < score 8 (chi-square = 6, p = 0.01). Four patients (15%) who were nonresponders at week 1 responded after 2 weeks. The results show a statistically different outcome after 2 weeks of treatment and suggest the necessity of longer trials of phototherapy.

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 in seasonal and nonseasonal depression

Ninety patients with major depressive disorder were classified according to seasonal (n = 68, 50 women) or nonseasonal (n = 22, 17 women) pattern according to DSM-III-R. They were also clinically evaluated and rated before and after morning (0600-0800) or evening (1800-2000) light treatment for 10 days in a room with a luminance of 350 cd/m2 (approximately 1500 lx) at eye level. Mood ratings were performed using both the Comprehensive Psychopathological Rating Scale and the Hamilton Depression Rating Scale. Depressed patients with seasonal pattern improved significantly more than those with a nonseasonal pattern suggesting a specific nonplacebo effect of light treatment in depressed patients with seasonal pattern. There were no significant differences in outcome when light treatment was given in the morning or in the evening, and not between patients with and without atypical symptoms such as carbohydrate craving or increased appetite.