Having a good time can strengthen different centres in the brain and help it grow healthy brain cells, or neurones, while stress can shrink brain structures and slow down the growth of neurones.
Dr Ian Reid, professor of mental health at the University of Aberdeen, told delegates that for many years psychiatrists believed that poor mental health was just caused by imbalances in various brain chemicals.
However, new research has shown that different parts of the brain, such as the hippocampus, the amygdala, the cingulate gyrus and the prefrontal cortex - all of which direct our emotions and behaviour; change shape and shrink when someone is under stress.
People with depression, post-traumatic stress disorder, borderline personality disorder and those with a history of childhood abuse or adversity show changes in the structure of their brains as measured by brain scans. The good news, said Prof Reid, is that drug treatment or behavioural therapy can make the human brain structure return to normal.
Similarly, it was thought that human beings were born with a fixed number of brain cells, but again research has shown that humans grow new cells a processes called neurogenesis throughout their lives in an area of the brain called the hippocampus. "We don't make that many maybe 30 or 40 but you only need a network of 30 to breathe and 40 for orgasm" said Prof Reid.
Many of the studies on deprivation in childhood are conducted on animals, with baby rats being taken away from their mothers for several hours, then returned and the changes to their brains compared to rats which had remained with their mothers. The separated rats showed brain changes. Similarly, rats who enjoyed an enriched environment with exciting toys in their cages had healthier brains than rats with few, if any, toys.