In the 1990s, David H. Barlow (professor of psychology and psychiatry at Boston University and founder of the Center for Anxiety and Related Disorders) and colleague Timothy Brown began a closer study of the role neuroticism played in the mood and anxiety disorders found in their patients. What they discovered was that negative affect contributed substantially to all the disorders in the clinic — in particular generalized anxiety disorder and depression. The findings have since been replicated many times, Barlow said.
Today it is believed that two other factors play a key role in shaping the neurotic temperament. The first is that people predisposed to this behavior don’t handle intense emotions well. One study conducted a few years ago confirmed that patients in Barlow’s clinic found emotions less acceptable than well-matched participants outside the clinic and typically tried to suppress them.