Oneirophrenia is a hallucinatory, dream-like, state caused by several conditions such as prolonged sleep deprivation, sensory deprivation, or drugs (such as ibogaine).
It has some of the characteristics of simple schizophrenia, such as a confusional state and clouding of consciousness, but without presenting the dissociation symptoms which are typical of this disorder.
Persons affected by oneirophrenia have a feeling of dream-like unreality which in its extreme form may progress to delusions and hallucinations. Therefore, it is considered a schizophrenia-like acute form of psychosis which remits in about 60% of cases within a period of two years. It is estimated that 50% or more of schizophrenic patients present oneirophrenia at least once.