"Some people have become so cynical that they don't believe in anything any more. In them, healthyscepticism has been replaced by a total breakdown in trust, the belief that everybody lies.
Only the severe end was even considered. There was no sense of spectrum. Paranoia was very much seen as inexplicable, un-understandable, if anything some kind of biological system that had gone wrong. I remember thinking that seemed very reductionalist, that there must be some kind of psychology to it. Once I started looking at it as a spectrum, once you make the connection to things such as depression and anxiety, it really opens it up. People with depression have higher levels of paranoia because of a sense of vulnerability and low self-esteem. Anxiety is linked too. But whereas anxiety may lead to fearing harm from a spider, or of being humiliated in a social situation, it doesn't lead to a belief that the spider or others intend to humiliate or hurt us. It's the attribution of intent that distinguishes paranoia.
This is another main reason why I believe paranoia is on the increase. Because we are constantly reminded, in the press, of threats from other people, we overestimate the chances of these events happening to us. There is a lot of research on this. It is what is known as the 'availability heuristic'. We make an estimate of the likelihood of a particular event simply by how easily we bring it to mind. Our children are getting fat because we aren't letting them out to play enough. We're scared they will be run over or abducted by strangers. In fact, the risks to the health from obesity are much higher than the risks of either of those events.