"A healthy brain is one that can perform all the mental processes that are collectively known as cognition, including the ability to learn new things, intuition, judgment, language and remembering" [the CDC]
Cognition, which originates from the Latin verb cognosco (‘to know’), refers to mental processes such as attention, memory, knowledge, reasoning, computation, decision-making, judgement, language function, perception, visuospatial abilities, and aspect of social interaction (social cognition). Psychologists distinguish it from emotion and behaviour (conation), although all are dependent on brain processes that are often seamless. As with other aspects of health, cognition varies from individual to individual, and with age, and a host of other factors. Good cognition is critical for optimal functioning at work, in the family and the community. As mental health usually has a focus on normality of emotion and behaviour, it is appropriate to place a separate emphasis on cognition, and state that there is ‘no health without cognitive health’.
Globally, the rising incidence of dementia has negatively impacted cognitive health. There are approximately 50 million people living with dementia worldwide of which Alzheimer's disease is the most common (contributing to 60–70% of cases); this is projected to reach 82 million in 2030 and 152 in 2050. Whilst dementia is one of the major causes of disability and dependency among older people worldwide, it also has a physical, psychological, social, and economical impact, not only on people with dementia, but also on their carers, families and society at large.
Beyond dementia, there are growing number of people with mild cognitive impairment (MCI) who have more subtle impairment owing to varying levels of cognitive dysfunction not severe enough to be diagnosed as dementia. In addition, whilst most cognitive health issues address ageing populations, cognitive health is not age limited. For instance, in children, the worldwide prevalence of attention-deficit hyperactivity disorder is estimated at 5%, with a considerable impact on education, work performance, and functioning in society. Cognition may be affected by many disorders in both childhood and adulthood including psychiatric disorders such as depression and anxiety which can often lead to impairment in concentration and working memory,
Cognitive health is recognized as a major factor in ensuring quality of life and optimal independence across the life span. Impaired cognition is associated with considerable socioeconomic burden, adding to the public health imperative.