Sundowning

The following social, economic, and physiological adverse outcomes are correlated with individuals affected by sundowning and their caregivers: • Long-term admission to psychiatric care facilities. • Increased stress and burnout of caregivers due to the timing of sundowning symptom onset. ==Symptoms==

Symptoms are not limited to but may include: • Increased general confusion as natural light begins to fade and increased shadows appear. • Agitation ==Causes==

While the specific causes of sundowning have not been empirically proven, some evidence suggests that circadian rhythm disruption increases sundowning behaviors. In humans, sunset triggers a biochemical cascade that involves a reduction of dopamine levels and a shift towards melatonin production as the body prepares for sleep. In individuals with dementia, melatonin production may be decreased, which may interrupt other neurotransmitter systems. Other causes or precipitating factors that may lead to sundown syndrome may include hormonal changes, disturbances in REM sleep, individual and/or caregiver fatigue, inappropriate medication use, or being predisposed to behavioral disorders from chronic neurological diseases. Resources in an institution's environment can also play a role as a symptom trigger. A reduced number of staff in the evening can be attributed to more unmet needs and a lower threshold for agitation for individuals with sundown syndrome. Sundowning should be distinguished from delirium, and could be presumed to be delirium when it appears as a new behavioral pattern until a causal link between sunset and behavioral disturbance is established. People with established sundowning and no obvious medical illness may be suffering from impaired circadian regulation, or may be affected by nocturnal aspects of their institutional environment such as shift changes, increased noise, or reduced staffing (which leads to fewer opportunities for social interaction). Delirium is generally an acute event that can span hours to days. In addition to the effects on circadian rhythm, serotonin is also known to be involved in the regulation of aggression. Risk factors Elderly people often experience multiple comorbidities that may contribute to the phenomenon of sundowning syndrome through neurodegeneration. • Neurological disorders: Alzheimer's disease, Parkinson's disease, Huntington's disease, Lewy body dementia, fronto-temporal dementia, subcortical dementia. • Neurobehavioral disorders: anxiety and depression. ==Treatment==

Scant clinical trials exist to guide treatment. Non-pharmacological treatments • If possible, a consistent sleeping schedule and daily routine that a patient is comfortable with can reduce confusion and agitation. • Reducing the amount of overwhelming noise in the late afternoon or early evening can help the transition to sleep. • Exercising at consistent times daily has been proposed to improve circadian rhythm and reduce the symptoms of sundown syndrome in people with Alzheimer's and dementia. Pharmacological treatments • Some evidence supports the use of melatonin to induce sleep. • Drug classes such as hypnotics, benzodiazepines, acetylcholinesterase inhibitors (AChIs), N-methyl D-aspartic acid antagonists (NMDA), selective serotonin reuptake inhibitors (SSRIs), and sedative antipsychotics have been used to treat sundowning, but their side effects limit their overall effectiveness in a risk versus benefit balance. Various side effects in the risk category include increased fall risk, vivid dreams, or nocturnal agitation. == Research directions ==

There are several pathways in the pipeline for scientists seeking therapeutic options for sundowning syndrome. • NADH cytochrome C reductase is an enzyme involved in the synthesis of neuron energy. Stress, hypometabolism, and oxidative damage may decrease physiologic reserve in the elderly and can lead to a decrease in neuron energy production and an increase in neuron damage. == Controversy ==

In addition to sundown syndrome not being officially recognized in the DSM-5, there is also the thought that sundown syndrome may be a phenomenon of caretakers' perception of patient agitation in the early afternoon to evening. == References ==