Bio-psycho-social model of mental health

This model was proposed by an American psychiatrist - George Engel, to explain mental health. It is derived from the General systems theory. This theory looks at the universe at different levels - from the level of subatomic particles to the macro cosmic universe, including living organisms. each level is more complex than the lower level.
Bio-psycho-social model proposes that mind is emerging from the brain's unique organization. The body is organized as cells, which aggregate to form tissues. Collection of tissues with similar function form organs (e g: liver is formed by a collection of specialized cell called hepatocytes). Organs with related functions are grouped together as organ systems. For example liver, stomach, intestines etc together form the gastro intestinal system. Brain is viewed as the highest level of organization of all the organ systems. All the other systems like heart and blood vessels, kidneys and urinary bladder etc are there to support the brain.
The property of consciousness emerges at the level of brain. But at the same time social and psychological factors can influence the way we live in this world and relate to our fellow human beings.
Social factors operate at the interpersonal level. Psychological factors operate within our subjective world - our own private fears, doubts, fantasies, feelings etc.
Brain is the final common pathway for all these experiences to enter our mind. The electrical and chemical processes taking place in the neurons and their connections give us our subjective world. But how does the physical events get transcoded as our rich internal world ? Neuroscientists are still working on this. It will be the ultimate mystery of nature. Will man be able to solve this riddle ?