Are we still in the dark? A systematic review on personal daily light exposure, sleep-wake rhythm, and mood in healthy adults from the general population.

Insufficient light exposure is assumed to be related to a wide array of health problems, though few studies focus on the role of whole-day light exposure in the habitual setting in the development of these health problems. The current review aims to describe the association between personal light exposure in the habitual setting and sleep-wake rhythm and mood in healthy adults from the general population. Five databases (Embase, Medline Epub, Web of Science, PsycINFO, and Google Scholar) were searched in June 2019. The inclusion criteria included: assessment directly of light exposure on the participants for at least one full day; reporting on both individual personal light exposure and outcomes. The quality of the papers was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies of the National Heart, Lung and Blood Institute. The current review followed the PRISMA guidelines. In total, 8140 papers were identified in the database search. Twenty-five papers were eventually included in this review. All included studies were cross-sectional, and individual light exposure was usually measured with a wrist-worn device. Five studies received a "good" quality rating, 16 received a "fair" rating, and the remaining 4 a "poor" quality rating. The overall quality of the included studies was considered low because of the lack of intervention studies and the fact that light exposure was measured on the wrist. Given the low quality of the included studies, the current review can only provide a first exploration on the association between light exposure and sleep-wake rhythm and mood in healthy adults from the general population. Limited evidence is presented for a positive relationship between the amount and timing of light exposure on the one hand and rest-activity rhythm and some estimates of sleep architecture on the other. The evidence on an association between light exposure and circadian phase, sleep estimates, sleep quality, and mood is conflicting. Data from intervention studies are needed to gain insight into the causal mechanism of the relationship between light exposure and sleep-wake rhythm and mood.

Hair glucocorticoids in adults with intellectual disabilities and depressive symptoms pre- and post-bright light therapy: First explorations.

BACKGROUND: Depressive symptoms and stress are common in adults with intellectual disabilities. Our aim was to explore long-term biological stress levels, assessed by hair cortisol (HairF) and cortisone (HairE) concentrations, in adults with intellectual disabilities and depressive symptoms and to investigate the effects of bright light therapy (BLT) on hair glucocorticoids. METHOD: Scalp hair samples (n = 14) were retrospectively examined at baseline and post-BLT (10.000 and 300 lux). Liquid chromatography-tandem mass spectrometry was used to measure hair glucocorticoids. RESULTS: A significant correlation was found between baseline HairF and depression scores (r = .605, p = .028). Post-intervention HairE levels were significantly increased ([95% CI: 11.2-17.4 pg/mg], p = .003), in particular after dim light (300 lux) ([95% CI: 10.0-18.3 pg/mg], p = .020). CONCLUSIONS: This study showed that retrospectively examining biological levels of stress in adults with intellectual disabilities seems a potentially promising and objective method to gain insight in the stress level of adults with intellectual disabilities.

The effect of bright light therapy on depressive symptoms in adults with intellectual disabilities: Results of a multicentre randomized controlled trial.

BACKGROUND: Although a large number of adults with intellectual disabilities have depressive symptoms, non-pharmacological treatments are scarce. The present authors investigated whether bright light therapy (BLT) is effective in decreasing depressive symptoms compared to care as usual. METHODS: This multicentre randomized controlled trial consisted of three study groups (10,000 lux BLT, dim light BLT and a no-BLT group). Participants received BLT for 30 min in the morning (14 consecutive days), additional to their regular care. Primary outcome was as follows: depressive symptoms measured with the ADAMS Depressive Mood subscale 1 week after the end of BLT (same time period in the no-BLT group). RESULTS: Forty-one participants were included in our trial. In both BLT groups, a significant decrease in depressive symptoms was seen. No significant differences were found between 10,000 lux BLT and no-BLT (p = .199) and no significant differences between dim light BLT and no-BLT (p = .451). A minimum amount of side effects and no adverse events were reported. CONCLUSIONS: In both BLT interventions, a decrease in depressive symptoms was seen. With 10,000 lux BLT, depressive symptoms decreased even below the clinical cut-off point, which makes BLT a promising intervention for clinical practice.

Reliability and validity of the Dutch Anxiety, Depression And Mood Scale in adults aged <50 years with intellectual disabilities.

BACKGROUND: Reliable and valid screening instruments for depression and anxiety are needed for adults with intellectual disabilities. METHODS: Internal consistency (n = 198), inter-rater reliability (n = 41), test-retest reliability (n = 37) and criterion validity (n = 43) were studied in adults aged between 18 and 49 years. Internal consistency was also studied in a sample with epilepsy (n = 98). RESULTS: Internal consistencies of the Dutch ADAMS total scale and subscales were satisfactory to good (α = 0.76-0.92), as well as in the subgroup with epilepsy (α = 0.74-0.88). Inter-rater reliability and test-retest reliability were fair to excellent for the total scale (ICC's: 0.57-0.84) and subscales (ICC's: 0.43-0.86). The criterion validity of the Dutch ADAMS Depressive Mood subscale was good with a sensitivity of 88% (95% CI: 53%-98%) and a specificity of 80% (95% CI: 64%-90%). CONCLUSIONS: Our study shows that the Dutch ADAMS is a reliable and valid instrument for adults aged between 18 and 49 years with intellectual disabilities (and comorbid epilepsy).

A multicenter randomized controlled trial for bright light therapy in adults with intellectual disabilities and depression: Study protocol and obstacle management.

Due to the limited cognitive and communicative abilities of adults with intellectual disabilities (ID), current treatment options for depression are often limited to lifestyle changes and pharmacological treatment. Bright light therapy (BLT) is an effective intervention for both seasonal and non-seasonal depression in the general population. BLT is an inexpensive, easy to carry out intervention with minimal side effects. However, knowledge on its anti-depressant effect in adults with ID is lacking. Obstacles in realizing a controlled intervention study in this particular study population may have contributed to this lack. To study the effect of BLT on depression in this population, it is necessary to successfully execute a multicenter randomized controlled trial (RCT). Therefore, the study protocol and the management of anticipated obstacles regarding this trial are presented.