Clearly, high anxiety and stress can cause all sorts of problems for us. But in some rare cases they can even lead to psychosis, an extreme mental state in which delusions and/ or hallucinations occur and thought processes may be altered.

Psychologists have suggested that psychosis is waking reality processed through the dreaming brain, and this has resonated with many people who have suffered from psychosis. "It was like living in the weirdest dream," sufferers have told their psychologists.

When we are dreaming, we are in the REM state. And when we experience bizarre events in dreams, we often at the time don't even find them odd. We are also less sensitive to pain or to other sensations (for instance, we don't feel uncomfortable at the time but might on waking, if one of our arms is trapped in an awkward position). And, if someone calls to us while we are asleep, their voice may be incorporated into our dream, thus appearing to be inside our own heads. All of this mirrors the altered reality, delusions, hallucinations and desensitisation that occur in psychosis too.

As explained earlier, when anxious thoughts are bombarding the brain, the need to discharge them through REM sleep is exacerbated. This leads to longer and more intense periods of REM sleep, in effect damaging the REM sleep mechanism. In cases of extreme stress and anxiety, it is conceivable that the damage could be even more pronounced, and that an individual could be dipping in and out of the REM state when awake. Although anxiety and stress may rarely result in psychosis, psychosis is almost always preceded by stress.

For instance, a psychologist once treated a man called Vic who had begun to hallucinate that his wife had turned into his mother. It didn't take Joe long to find out that Vic was under considerable stress at work and this, in tum, was putting his marriage under strain. Whenever his wife got angry with him or he felt she was nagging him, the hallucination occurred. Vic had had a very difficult relationship with his mother, who had been extremely controlling.

The psychologist suggested to Vic that he was experiencing dream phenomena, brought on by stress. He was pattern matching to images of his mother when his wife behaved in certain ways but, because his heightened stress pushed him into a waking REM state at such times, he experienced his wife as his mother instead of just being reminded of her. This explanation reduced Vic's anxiety considerably and he was able, with the psychologist's help, to calm down and address the stresses he was under in a practical way.

Continued in this article: Drugs are not the answer to anxiety