What links schizophrenia and dreaming? Common phenomenological and neurobiological features of schizophrenia and REM sleep

Aim. The aim of this theoretical study is to present common phenomenological and neurobiological features of schizophrenia and REM sleep.Results. A review of professional literature was conducted in order to synthesize current findings about associations between schizophrenia and REM sleep. Many researches reveal that both states share some common phenomenological and neurobiological features. Autism, lack of insight and a loss of autonomy in relation to mental content are just some of the characteristics that occur on a phenomenological level in both dreams during REM sleep (lucid dreaming excluded) and schizophrenia. Data from experimental conditions revealed that the waking mentation of patients suffering from schizophrenia has a similar degree of formal cognitive bizarreness as dream narratives obtained from both non-clinical and clinical populations. On the other hand, some common neurobiological features of the REM sleep stage and schizophrenia are: lack of central inhibitory processes, intracerebral disconnections, dysfunction of the dorsolateral prefrontal cortex or nucleus accumbens and disturbed responsiveness. Moreover, there is similaractivation of dopamine, acetylcholine, noradrenaline, serotonin and glutamate in both states.Conclusions. Common phenomenological and neurobiological characteristics of these two states suggest that data about REM sleep could help introduce a useful experimental model of schizophrenia.