Background: The majority of people with dementia have behavioral and psychological symptoms of dementia (BPSD), including depression, anxiety and agitation. These may be elicited or aggravated by disrupted circadian rhythms. Bright light treatment (BLT) is a promising non-pharmacological approach to the management of BPSD, but previous research has yielded mixed results.Methods: Eight nursing home dementia units (1 unit = 1 cluster) with 78 patients were invited to participate in a cluster randomized controlled trial from September 2017 to April 2018 investigating the effects of BLT on sleep and circadian rhythms (primary outcome) and BPSD (secondary outcome). Ceiling mounted LED-panels were installed in the intervention group (four units), providing light at 1000 lx and 6000 K (vertically at 1.2 m) between 10 a.m. and 3 p.m., with lower values in the mornings and evenings. Standard indoor light was used in the control group (four units). BPSD were assessed with The Cornell Scale for Depression in Dementia (CSDD) and the Neuropsychiatric Inventory Nursing Home Version (NPI-NH). Data collection took place at baseline and after 8, 16 and 24 weeks. Multilevel regression models with and without false discovery rate correction were used for the analysis, with baseline values and dementia stage entered as covariates.Results: Sixty-nine patients were included in the study at baseline. Compared to the control group, the intervention group had a larger reduction on the composite scores of both the CSDD (95% CI = − 6.0 – − 0.3) and the NPI-NH (95% CI = − 2.2 – − 0.1), as well as on the NPI-NH Affect sub-syndrome, and the CSDD Mood related signs sub-scale at follow-up after 16 weeks. With FDR correction, the group difference was significant on the CSDD Mood related signs sub-scale (95% CI = − 2.7 – − 0.8) and the NPI-NH Affect sub-syndrome (95% CI = − 1.6 – − 0.2). No differences were found between conditions at weeks 8 or 24.Conclusion: Compared to the control condition, affective symptoms were reduced after 16 weeks in the group receiving BLT, suggesting BLT may be beneficial for nursing home patients with dementia.Trial registration: ClinicalTrials.govIdentifier:NCT03357328. Retrospectively registered on November 29, 2017.

Adequate illumination plays an important part in providing a healthy environment for nursing home patients with dementia. With increasing awareness of non-visual responses to light, new approaches to quantifying illuminance have emerged. In the present study, we assessed the illuminance in nursing home dementia units in terms of melanopic equivalent daylight illuminance, a metric which aims to quantify the non-visual physiological effects of light by weighing irradiance according to non-visual photoreception. It is among the most comprehensive studies of light conditions conducted in dementia units in terms of melanopic equivalent daylight illuminance to date, and the first to elucidate seasonal differences in melanopic illumination. Light conditions were assessed in all 15 nursing homes with dedicated long-term dementia units in Bergen municipality (60.39°N), Norway, during summer and winter. Results indicated that seasonal differences and gaze direction had some impact on melanopic equivalent daylight illuminance, but most measurements still fell below even conservative recommendations across seasons. The findings indicate a need for additional light sources that can compensate for limited natural daylight in dementia units. The ubiquity of insufficient melanopic equivalent daylight illuminance in dementia units suggests a role for lighting interventions in future research seeking to improve entrainment, sleep and mental health of dementia unit residents.

Bright light treatment is an effective way to influence circadian rhythms in healthy adults, but previous research with dementia patients has yielded mixed results. The present study presents a primary outcome of the DEM.LIGHT trial, a 24-week randomized controlled trial conducted at nursing homes in Bergen, Norway, investigating the effects of a bright light intervention. The intervention consisted of ceiling-mounted LED panels providing varying illuminance and correlated color temperature throughout the day, with a peak of 1000 lx, 6000 K between 10 a.m. and 3 p.m. Activity was recorded using actigraphs at baseline and after 8, 16, and 24 weeks. Non-parametric indicators and extended cosine models were used to investigate rest–activity rhythms, and outcomes were analyzed with multi-level regression models. Sixty-one patients with severe dementia (median MMSE = 4) were included. After 16 weeks, the acrophase was advanced from baseline in the intervention group compared to the control group (B = −1.02, 95%; CI = −2.00, −0.05). There was no significant difference between the groups on any other rest–activity measures. When comparing parametric and non-parametric indicators of rest–activity rhythms, 25 out of 35 comparisons were significantly correlated. The present results indicate that ambient bright light treatment did not improve rest–activity rhythms for people with dementia.

Rates of gambling disorder (GD) have been found to be higher among people receiving disability benefit, but few studies have investigated whether receiving disability benefit prospectively actually increases the risk of GD. The present study investigated whether those with a disability benefit had an increased risk of developing GD using a case-control design. The study sample was retrieved from the Norwegian Patient Registry (NPR, N = 5,131) and consisted of all adults in Norway (18 years and older) who had received a GD diagnosis (F63.0 according to ICD-10) between 2008 and 2018. The study group was age and sex matched with a random sample from the (1) general population (FD-trygd, n = 30,164), and (2) and individuals with other somatic or psychiatric illnesses (NPR, n = 30,476). The results of logistic regression analysis showed that people receiving disability benefit had higher odds of later being diagnosed with GD compared to the general population (odds ratio [OR] = 2.27, 95% CI [2.02, 2.54]), and compared to individuals in the NPR (OR = 2.13, 95% CI [1.90, 2.38]). Recipients of disability benefit constitute a group who is vulnerable in terms of developing GD. Although the present study found evidence for a prospective association, causality could not be established. The study identified a cohort that may benefit from targeted prevention and intervention strategies regarding gambling behavior.