Quantitative-Qualitative Assessment of Dream Reports in Schizophrenia and Their Correlations with Illness Severity

People with schizophrenia spectrum disorders report fewer and shorter dreams than healthy controls, with fewer characters, settings, and emotions. The reduction in emotional content in dreams correlates with greater symptom severity, suggesting that dreaming plays a role in emotion regulation during wakefulness—a function that may be impaired in psychosis.

Study at a glance

Abstract

Dreams and positive symptoms of schizophrenia are similar in many aspects, such as bizarre-ness, impairment of reality testing, intense emotional participation. Hallucinations, delusions, and disorganized thoughts have been proposed to be an intrusion of the dreaming state in wake-fulness: conversely, psychotic patients’ abnormal cognitive and behavioral features could over-flow into sleep, transferring peculiar features to their dreams which would differ, in quantity and quality, from those of healthy people. Here we assess this latter hypothesis by analyzing the dreams of 46 patients, hosted in a residential facility or in a day-treatment center, affected by disorders of the schizophrenic spectrum with psychotic symptoms, versus those of 28 healthy controls, in terms of several quantitative and qualitative characteristics. In patients, we also in-vestigated whether dream variables correlated with the severity of symptoms assessed via the Brief Psychiatric Rating Scale. Overall, patients reported fewer and shorter dreams than controls, with a reduction of many ele-ments like characters and settings. The greatest differences regarded emotions, which were less frequent in patients and inversely correlated with symptoms’ severity. This evidence supports the hypothesis that dreams are crucial for emotion regulation during wakefulness and that this func-tion could be totally or partially ineffective in psychoses.