When depression latches on, it settles in and rearranges you to get a better grip. You stop loving the things you loved. You stop looking forward to anything. You feel hopeless and you feel sad.
In the Western world, 1 in 10 people will suffer depression during the course of their life. It has more of an effect on physical health than diabetes or arthritis.
A fascinating theory has been put forward by Turhan Canli PhD, Associate Professor of Psychology and Radiology at Stony Brook University, which could change the future direction for research and treatments of depression.
According to Dr Canli, depression should be re-conceptualised as an infectious disease. His argument is a compelling one.