Psychosis — a dream-like state of mind?
Have you ever thought of psychosis as a dream-like state of mind? Dreaming does actually bear strong similarities with the psychotic state of mental illnesses such as schizophrenia. Psychotic states are characterized by hallucinations, loosening of associations, incongruity of personal experience, and a loss of self-reflective capacity. Dreams can also be seen as a kind of delusional thought during which there is a complete lack of insight into one’s true state of consciousness. Both the psychotic patient and the dreamer are in a state of acceptance of nonsensical experiences as real.
That dreaming may be a model for psychosis is a long-standing idea that has now been supported by recent studies on dream phenomenology. There are extensive similarities in measures of cognitive bizarreness between the waking thoughts of psychotic patients and dream reports of both psychotic patients and healthy controls. But whereas healthy subjects shut down those hallucinations while awake, psychotic patients continuously experience such dream-like mental activity.
One of the key aspects of the dreaming-psychosis model is the issue of insight, i.e. awareness of the mental state. Lack of insight into the dream state is a hallmark of the dream experience; likewise, 50–80% of schizophrenia patients have poor insight into their illness.
However, in contrast to normal dreaming, there is a special kind of dreaming in which the sleeping subject becomes fully aware of the mental state: lucid dreaming. In lucid dreams, the dreamer is aware that he is dreaming and is frequently able to control the ongoing dream. During normal rapid eye movement (REM) sleep, when the most vivid dreams occur, there is an increased activity in higher visual and motor areas, reflecting the occurrence of visuomotor hallucinations, the hallmark of typical dreaming.
In contrast, areas associated with willingness and critical thinking show decreased activity. During lucid REM sleep, on the other hand, there is increased activation of regions involved in attention and in higher cognitive processes like intelligence or working memory. Nevertheless, lucid REM sleep still includes all classic dream features such as visuomotor hallucinations, but the lucid dreamer can recognize dreams as such.
Lucidity during dreaming represents what patients during psychosis lack: insight into the delusional nature of their state of consciousness. Given these characteristics, it has been suggested that lucidity during dreaming may be a good model for insight in the dreaming-psychosis model. This model hypothesizes that the neural processes of lucid dreaming extensively overlap with those of insight into the psychotic state, and that the means to achieve lucidity during normal dreaming may also increase insight into the pathological state in psychotic patients.
Actually, for all brain regions associated with lucid dreaming there has been at least one study demonstrating the involvement of that region also in psychotic insight deficits; likewise, brain regions linked to insight problems in psychosis have shown remarkable overlap with brain regions in which activation increases during lucid dreaming, which strongly supports the theoretical idea that dreaming may indeed serve as a model of psychosis.
Interventions to promote insight are thought to be a promising alternative for schizophrenia therapy. Lucid dreaming can be trained, which makes this phenomenon an interesting tool and research topic, even though it occurs rarely in untrained subjects. Insight deficits in psychosis have been targeted with different interventions, but without noteworthy success.
Lucidity training has already been applied to other clinical settings such as nightmare therapy. If it proves to be successful in enhancing insight capabilities during psychosis, lucidity training may allow the psychotic patient to become aware of his state and, hopefully, even control it.
Originally published at brainblogger.com on December 6, 2014
Dresler M, Wehrle R, Spoormaker VI, Steiger A, Holsboer F, Czisch M, & Hobson JA (2014). Neural correlates of insight in dreaming and psychosis. Sleep medicine reviews PMID: 25092021
Kahn D, & Gover T (2010). Consciousness in dreams. International review of neurobiology, 92, 181–95 PMID: 20870068
Limosani I, D’Agostino A, Manzone ML, & Scarone S (2011). The dreaming brain/mind, consciousness and psychosis. Consciousness and cognition, 20 (4), 987–92 PMID: 21288741
Stumbrys T, Erlacher D, Schädlich M, & Schredl M (2012). Induction of lucid dreams: a systematic review of evidence. Consciousness and cognition, 21 (3), 1456–75 PMID: 22841958