Impairments in self-recognition (i.e. recognition of own thoughts and actions) have been repeatedly shown in individuals with schizophrenia. According to classical clinical characterizations, schizophrenia is included in a continuum encompassing a large range of genetic statuses, psychotic states and symptoms. The current meta-analysis aims to determine whether self-recognition is affected by individuals within the psychosis continuum.

Three populations were considered: people with an at-risk mental state for psychosis (ARMS), hallucination-prone individuals and unaffected relatives of patients with schizophrenia. Eleven studies contrasted self-recognition between these three populations (n = 386) and healthy controls (n = 315) and four studies used correlational analysis to estimate comparable effects (n = 629). Eligible studies used experimental paradigms including source-monitoring and self-monitoring.

We observed significantly reduced self-recognition accuracy in these populations [g = −0.44 (−0.71 to −0.17), p = 0.002] compared to controls. No influence of the type of population, experimental paradigm or study design was observed.

The present analysis argues for self-recognition deficits in populations with no full-blown psychotic symptoms represented across the continuum of psychosis.

Based on the observed clinical overlap between obsessive–compulsive disorder (OCD) and schizophrenia (SCZ), both conditions may share, at least in part, common cognitive underpinnings. Among the cognitive deficits that could be involved, it has been hypothesized that patients share a failure in their abilities to monitor their own thoughts (source monitoring), leading to confusion between what they actually did or perceived and what they imagined. Although little is known regarding source-monitoring performances in patients with OCD, numerous studies in patients with SCZ have observed a relationship between delusions and/or hallucinations and deficits in both internal source- and reality-monitoring abilities.

The present work compared source-monitoring performances (internal source and reality monitoring) between patients with OCD (n = 32), patients with SCZ (n = 38), and healthy controls (HC; n = 29).

We observed that patients with OCD and patients with SCZ displayed abnormal internal source-monitoring abilities compared to HC. Only patients with SCZ displayed abnormalities in reality monitoring compared to both patients with OCD and HC.

Internal source-monitoring deficits are shared by patients with OCD and SCZ and may contribute to the shared cognitive deficits that lead to obsessions and delusions. In contrast, reality-monitoring performance seems to differentiate patients with OCD from patients with SCZ.

We investigated whether source-monitoring deficits (here a discrimination between imagined and performed actions) underlie hallucinations among patients with a history of hallucinations in the course of their alcohol dependence.

We assessed 29 patients with alcohol dependence who had no history of hallucinations during their course of alcoholism and 29 patients with a history of at least one episode of hallucinations of any modality during their course of alcohol dependency. The control group consisted of 24 healthy participants. Participants were assessed with an action memory task. Simple actions were presented to the participants verbally or non-verbally. Some actions were performed physically and others were imagined. In the recognition phase, participants were asked whether the action was presented verbally or non-verbally (action presentation type discrimination) and whether the action was performed or imagined (self-monitoring). A confidence score related to self-monitoring responses was also obtained.

Alcoholics with a history of hallucinations misremembered imagined actions as perceived ones more frequently than patients without hallucinations, but not the reverse. Only patients with a history of hallucinations committed more errors of this type than healthy subjects. There were no group differences regarding discrimination between an action presentation type. Both clinical groups committed errors with a higher degree of confidence than healthy subjects.

Our results tentatively suggest that a specific type of source-monitoring deficit (i.e. confusing imagery with reality) may be involved in the hallucinations in patients with alcohol dependence. The findings are discussed in the light of a transdiagnostic approach to hallucinations.