The number of elderly in the society increases because of an increase in life expectancy due to improved medical care and prevention of disease and because of the baby boom from 1946 – 1970. Diagnosing mental disorders in the elderly is difficult, as mental health is tied to physical problems and it is thus difficult to distinguish between a normal age-related change in function and neurocognitive disorders.

There are differences in circadian rhythm (1), temperature levels (2), cortisol level (3), metabolism (4) and heart rate (5) over the course of the day in the elderly. There is a flattening of daily cycle (1), fewer hours of sleep (2), peak shifts to the morning (3) and increased need for naps (4) with normal ageing. This leads to a decrease in cognitive abilities, a shift in peak performance, decrease in memory consolidation and a higher risk of brain disorders.

A problem with medication for the elderly is that the elderly often experience multiple medical issues, they take a number of medications, their medication is not adjusted to their age, medications are often tested on the young and there is a lot of medication nonadherence.

Ageism is an irrational prejudice against old people and/or ageing. There are several biases about ageing or being old. This includes being lonely (1), focussing on poor health (2) and being unhappy (3). There is social selectivity in older people, a shift of attention from forming new social interactions to cultivating the few important social interactions and older people are better at emotion regulation.

Age effects are the consequences of being a certain chronological age. Cohort effects are the consequences of growing up during a particular time period. Time-of-measurement effects are the effects of testing people at a particular time in history (e.g: after a terror attack). Consequences of longitudinal studies include selective mortality.

The prevalence of mental disorders is lower in the elderly and this could be due to reporting bias, cohort effects and selective mortality in research, but it likely reflects better mental health due to growing out of symptoms and enhanced coping abilities.

Dementia is a descriptive term for the deterioration of cognitive abilities to the point that functioning becomes impaired. In frontotemporal dementia, there is rapid progression of the disease and memory is not severely impaired, but there is functional impairment of executive function (1), ability to inhibit behaviour (2), empathy (3) and there is hyperorality (4), compulsive or perseverative behaviour (5) and apathy (6). It is caused by a loss of neurons in the frontal and temporal regions of the brain.

In dementia with Lewy bodies (DLB), protein deposits called Lewy bodies form in the brain and cause cognitive decline. It often occurs in the context of Parkinson’s disease, but this is not necessary. It is likely to include visual hallucinations, fluctuating cognitive symptoms and intense dreams with movement and vocalizing. Vascular dementia is caused by cerebrovascular disease. The onset of dementia is quicker in vascular dementia than in other types of dementia.

Cognitive reserve is the idea that some people can compensate for a form of dementia by using alternative brain networks or cognitive strategies so that cognitive symptoms are less pronounced. The change in circadian rhythm with age plays a role in the development of many types of dementia, as sleep disruptions are often at the heart of mental disorders and sleep disruptions are part of many types of dementia.

The heritability of Alzheimer’s is ±79%. The apolipoprotein (ApOE-4) interferes with the clearing of beta-amyloid and could be a risk factor for Alzheimer’s together with depression. Exercise, cognitive engagement and diet are protective factors. The cause of Alzheimer’s includes excessive production and decreased clearance of beta-amyloid plaques, which leads to an accumulation of beta-amyloid plaques. There are also tangles, synaptic deficits and a loss of neurons in the hippocampus, entorhinal cortex. The cerebral cortex shrinks and the ventricles become enlarged.

Delirium is a clouded state of consciousness. It is caused by a medical condition, substance intoxication or withdrawal of toxin. The mortality rate of delirium is high if it’s untreated, but a complete recovery is possible if the underlying cause is treated promptly and effectively.