Our observations of hundreds of depressed patients had confirmed that excessive worry puts huge stress on the REM sleep mechanism. This led us to hypothesise that schizophrenia develops in those particularly imaginative, highly sensitive people who become so stressed that the REM sleep discharge mechanism cannot take the strain, and so their ability to separate waking reality from the metaphorical reality of the dream world (where the metaphors themselves seem totally real), becomes impaired. When they wake up, they cannot properly switch out of the REM state and become stuck in it.
Naturally their thinking is then predominantly driven from the right hemisphere, the part of the brain most active in metaphorical pattern matching and dreaming. Many of their bodily behaviours could be expected to derive from those found in normal dreaming. In other words, the left hemisphere’s role, which is normally to analyse and organise reality in a rational way, and is predominantly in charge during wakefulness, has been usurped. The delicate working partnership of the brain’s hemispheres has shattered.
This, to our minds, provides a plausible way of explaining the wide variety of psychotic symptoms. The phenomenon of ‘word salad’ – the loosening of meaningful associations between words and phrases that results in people talking in a stream of apparent nonsense – is just what one might expect if the left hemisphere of the brain were to be out of sync with the metaphorical mind of the right hemisphere, as the latter would continue to generate associations without waiting for the left hemisphere to check them out and articulate them.
Catatonia, where patients can stand, sit or lie motionless for long periods in strange postures, oblivious to pain, is what the body also does during REM state dreaming, when the anti-gravity muscles are paralysed. Indeed, resistance to pain is often observed among schizophrenic patients and is even more marked during severe episodes. This is easily understood when we realise that, in dreaming also, cut off from all sensation, we experience no physical pain. That, too, is a REM state phenomenon (and is why hypnotised people can have major surgery painlessly without anaesthetic, as we have discussed).
Hearing voices is entirely predictable from our theory too. Talking is primarily a left hemisphere activity, whereas right hemisphere activity is mainly concerned with processing pattern matching and tagging emotions to those patterns to prompt action. We don’t talk when the right hemisphere is dominant during dreaming in REM sleep, although talking whilst in slow-wave sleep is common (but the content rarely seems to make sense to the awake mind.) However, during a psychotic episode, if the person were in the REM state awake, there would still be some logical activity and thinking taking place in the left hemisphere.
But, because the REM state is not anticipating any input from the left hemisphere, it has to interpret those thoughts metaphorically and comes up with the image of alien voices, which can seem to be commenting on the person’s every move, or haranguing them or giving ‘instructions’. (It might be expected that such thoughts would often be critical because the left hemisphere would, to some degree, still be able to analyse what was going on and ‘logically’ know that the behaviour is not normal.) This could further be interpreted metaphorically by the right hemisphere as being spied upon, or being persecuted, or that aliens are inside their head or that they are being followed everywhere by strange ‘rays’ that know everything they are doing. (Neurophysiological evidence confirms that, when schizophrenic people are hearing voices, the speech centres in the left neocortex are activated. And other researchers have observed and filmed REM activity when patients hear voices.)
The visual hallucinations or delusions associated with psychosis are also totally characteristic of the dream state, the function of which is to generate such hallucinatory realities. Neuroscientists have shown the same neuronal pathways are activated in psychotic episodes. Whilst dreaming we all believe completely in the reality of our dreams, just as the schizophrenic person believes in their reality.
Creativity and mental illness
It has long been suggested that there is a connection between creativity and mental illness. Certainly, people prone to schizophrenia tend to come from creative families. And even if they themselves are not productively creative, then high rates of creativity are found among their siblings and other relatives.
Furthermore, creative people tend to be more sensitive to the emotional environment around them and are less robust in withstanding hostility, intolerance or criticism. Indeed, the higher the level of emotional criticism within the family context, the higher the rate of schizophrenic and depressive relapses. When people go into a psychotic REM trance due to emotional arousal any criticism may well be acting like a post-hypnotic suggestion, compounding the condition.