How has our understanding of dementia changed?
Our understanding of the brain and dementia have changed significantly over time. In ancient Egypt (200BC), the heart and the diaphragm were believed to contain our mental life. By the beginning of the Common Era during the Greek Empire (100AD), the location of the mind was believed to be the lungs and liver.
Modern understandings of the brain and mind
From the work of Rene Descartes in the 17th century, we have come to regard the brain as the locus of control for our body. The term ‘Cartesian dualism’ describes the separation of mind and body. However, Descartes himself acknowledged that we do not control the body using our minds ‘like a pilot in a ship’ - it’s much more complex than that.
What we think and feel is connected to what our body experiences. Regular bodily experiences and common thought processes can alter the connections in our brains. Brain pathways or what are called ‘cortical pathways’ develop from regular bodily activities - as actions are repeated, they develop memory traces that help us build our motor skills. These can be daily actions such as fastening buttons, tying shoe laces etc., to more specialist ‘in the hand’ knowledge such as touch typing, or carpentry. Through repetition, we learn to perform them without conscious effort. We can also develop particular ways of thinking: the emotional responses, gestures and postures we commonly adopt contribute to who we are - they make us recognisable to others as individuals.
It is now becoming increasingly common to describe the brain as if it were a computer processor - efficiently storing and retrieving information. But we do not upload information from our senses in the same way as a computer does - our brains are highly selective and can be unpredictable. When the brain is affected by a disease such as dementia, we are less able to rely on the brain to perform many of the cognitive and physical functions we take for granted.
Our understanding of dementia
The term ‘dementia’ was first coined in writing by the founder of modern psychiatry Philippe Pinel in 1797, but the term may have been in use before this time. It comes from the Latin ‘demens’, which is ‘without mind’.
Alois Alzheimer was researching brain diseases at Munich at the end of the 19th century/beginning of the 20th century. His name was given to describe what was at first considered to be a rare condition. Over the course of the 20th century, a number of sub-types were identified, grouped together into syndromes or classified as distinct conditions. For example, fronto-temporal dementia (FTD) was described from the late 19th century by Arnold Pick, whose name is associated with the entire FTD spectrum as Pick’s disease. Similarly, in 1912, Fritz Heinrich Lewy discovered ‘neuronal inclusions’ in people with Parkinson’s disease, which later became known as ‘Lewy bodies’.
By 1994 dementia was defined as ‘a loss of intellectual abilities of sufficient severity to interfere with social or occupational functioning’ by the American Psychiatric Association.
The last few decades have seen the most dramatic developments in scientific understanding of dementia. There is now greater public awareness and understanding of dementia as a progressive disease of the brain. Alzheimer’s disease is now a common household word, and other types of dementia are becoming better known. Because of increased understanding of the molecular biology of different diseases, there is increasing hope of improved treatments.
How has your personal understanding of dementia changed?
© Newcastle University, amended from Boller and Forbes 1998