Researchers at the European Science Foundation have been discussing the latest research on dreams. They looked into a phenomenon called lucid dreaming in which people are aware that they are dreaming. They found it creates distinct patterns of electrical activity in the brain similar to the patterns made by psychosis. In lucid dreaming the brain is said to be in a dissociated state having lost conscious control over mental processes such as logical thinking and emotional reaction - again something that also occurs in psychosis. People suffering from nightmares can sometimes be treated by training them to dream lucidly so that they can consciously wake up, something it is hoped could be applied to people with psychosis. Dreaming is thought to have emerged to enable early humans to rehearse responses to the many dangerous events they faced in real life and some researchers think that paranoid delusions might occur because of a replay of this "threat response rehearsal," during waking life. However, not all dreams are threatening and other scientists see them as part of a learning process consolidating information acquired during the day. This theory is supported by the fact that people often remember things better the day after they learnt them i.e. after a night's sleep, than shortly afterwards.
You can find out more about this research at