Social cognition in schizophrenia, Part 1: performance across phase of illness

Social cognitive impairments are consistently reported in schizophrenia and are associated with functional outcome. We currently know very little about whether these impairments are stable over the course of illness. In the current study, 3 different aspects of social cognition were assessed (emotion processing, Theory of Mind [ToM], and social relationship perception) at 3 distinct developmental phases of illness: prodromal, first episode, and chronic. In this cross-sectional study, participants included 50 individuals with the prodromal risk syndrome for psychosis and 34 demographically comparable controls, 81 first-episode schizophrenia patients and 46 demographically comparable controls, and 53 chronic schizophrenia patients and 47 demographically comparable controls. Outcome measures included total and subtest scores on 3 specialized measures of social cognition: (1) emotion processing assessed with the Mayer-Salovey-Caruso Emotional Intelligence Test, (2) ToM assessed with The Awareness of Social Inference Test, and (3) social relationship perception assessed the Relationships Across Domains Test. Social cognitive performance was impaired across all domains of social cognition and in all clinical samples. Group differences in performance were comparable across phase of illness, with no evidence of progression or improvement. Age had no significant effect on performance for either the clinical or the comparison groups. The findings suggest that social cognition in these 3 domains fits a stable pattern that has outcome and treatment implications. An accompanying article prospectively examines the longitudinal stability of social cognition and prediction of functional outcome in the first-episode sample.     

A closer look at the relationship between the subdomains of social functioning,social cognition and symptomatology in clinically stable patients with schizophrenia

Impairments in social functioning commonly seen in schizophrenia are thought to be mediated by deficits in the domains of social cognition. Some previous research has explored how social cognitive skills and psychotic symptoms are associated with social functioning, however these associations are still under debate. The main aim of this study was to investigate the relationship between different domains of social cognition and psychotic symptomatology, and also to look at the relationships with individual subdomains of social functioning within a clinically stable schizophrenia population. 45 outpatients were recruited and symptoms were assessed with the PANSS, and measures of emotion processing, affective and cognitive theory of mind (ToM), mental state reasoning attributional biases, and social functioning were taken. A correlational analysis was performed with the data. Following this, a regression analysis was used to reveal which domains of social cognition best predicted psychotic symptoms. In this stable group of patients, our results support the suggestion of a likely distinction between affective and cognitive components of ToM. The study also demonstrated that ToM and mental state reasoning were the best predictors of psychotic symptoms. Here we reveal that cognitive ToM had the most widespread relationship with social functioning, across multiple subdomains, while only some specific subdomains of social functioning correlated with other domains of social cognition and symptomatology. Further to this, positive symptoms were associated with much fewer subdomains of social functioning than negative and general symptoms. These findings imply that different aspects of social functioning may be served by different domains of social cognition and symptomatology.     

The Effect of Context Processing on Different Aspects of Social Cognition in Schizophrenia

Background: It is well known that individuals with schizophrenia have impaired social cognition. The construct of social cognition involves several components, including perception, interpretation, and the ability to integrate context (Adolphs R. The neurobiology of social cognition. Curr Opin Neurobiol. 2001;11:231–239; Brothers L. The social brain: a project for integrating primate behavior and neurophysiology in a new domain. Concepts Neurosci. 1990;1:27–61). Importantly, a number of studies have suggested that deficits in context processing underlie cognitive dysfunction in schizophrenia (Penn DL, Corrigan PW, Bentall RP, Racenstein JM, Newman L. Social cognition in schizophrenia. Psychol Bull. 1997;121(1):114–132; Green MF, Nuechterlein KH. Should schizophrenia be treated as a neurocognitive disorder? Schizophr Bull. 1999;25:309–319). Thus, the purpose of the current study was to investigate the relationship between context processing and different aspects of social cognition in schizophrenia. Method: Individuals with schizophrenia (n = 41) and the healthy controls (n = 32) participated in this study. The participants completed 2 sections of The Awareness of Social Inference Test: (1) social inference minimal (SI-M) and (2) social inference enriched (SI-E). They also completed face and voice emotion discrimination tasks. In addition, we used the AX-Continuous Performance Test (AX-CPT) to measure context processing and the n-back task to measure working memory more generally. Results: AX-CPT performance in schizophrenia was positively correlated with both SI-M and SI-E performance but not with either the face or the voice discrimination. Furthermore, the correlation between AX-CPT performance and SI-M/SI-E performance was significantly stronger in individuals with schizophrenia than in controls. Conclusion: These results suggest that impairments in context processing are related to inferential components of social cognition in schizophrenia but not to the ability to recognition facial or vocal emotion. As such, deficits in context processing may contribute to deficits in both “hot” and “cold” aspects of cognition in schizophrenia.     

A multidimensional assessment of social cognition in psychometrically defined schizotypy

Individuals with schizophrenia exhibit impairments in multiple social cognitive domains. There is evidence that these impairments may be trait-related vulnerability markers for schizophrenia. However, the literature focusing on individuals vulnerable to developing schizophrenia-spectrum disorders, referred to as schizotypy, has produced inconsistent findings. This study's primary aim was to provide a more comprehensive understanding of social cognitive functioning within schizotypy than previous studies by employing a broad array of measures to assess multiple social cognitive domains, and examine how these domains relate to specific schizotypy traits (i.e., positive, negative, and disorganized) and Quality of Life (QOL). Facial emotion recognition, Theory of Mind (ToM), and aspects of emotional intelligence related to regulating one's own emotions (emotion management) and other's emotions (social management) were measured. Individuals with psychometrically defined schizotypy (n=36) and controls (n=26) were examined. The schizotypy group performed significantly worse than controls on facial emotion recognition, ToM, and emotion management, but not social management. Generally speaking, poorer social cognition performance was not a function of specific schizotypy traits. However, negative traits were associated with poorer facial emotion recognition, and disorganized traits were associated with better social management. Facial emotion recognition was associated with QOL in the schizotypy group.     

Neurocognitive predictors of social cognition in remitted schizophrenia

Knowledge of how specific neurocognition (NC) abilities predict social cognition (SC) in schizophrenia has potential to guide novel integrated cognitive-remediation therapies. The scope of studies conducted in this field is limited as they have not examined a comprehensive set of SC domains and they employ small sample sizes of heterogeneous patient groups. We studied a broad range of NC (sustained attention, processing speed, verbal/visual memory and visual processing/encoding, cognitive flexibility and planning) and SC [different levels of theory of mind (ToM)], attributional bias, emotion recognition and social perception] abilities in 170 remitted schizophrenia patients. Multivariate regression analyses revealed attention and planning as predictors of 1st order ToM. Memory encoding was the strongest predictor of 2nd order ToM. Faux-pas recognition, social perception and emotion recognition were influenced by a combination of cognitive flexibility and memory encoding abilities. Overall, NC predicted anywhere between ~4% and 40% of variance observed in specific SC sub-dimensions of attributional bias (4%), 1st order (19%) and 2nd order (12%) theory of mind, faux-pas recognition (28%), social perception (29%) and emotion recognition (39%). Individual SC abilities are predicted by distinctive as well as shared NC abilities. These findings have important implications for integrated cognitive remediation.     

Do patients with high-functioning autism have similar social cognitive deficits as patients with a chronic cause of schizophrenia?

Objective: There is substantial evidence that both patients with schizophrenia and patients with autism spectrum disorders (ASD) have impaired social cognition including theory of mind (ToM) deficits. However, it remains unclear if both verbal (explicit) and non-verbal (implicit) ToM as well as social perception are similarly affected in both disorders.

Methods: Twenty-one patients diagnosed with schizophrenia and 11 patients diagnosed with ASD were matched one-to-one to healthy controls based on gender, age, and educational level. Social functioning was measured by Personal and Social Performance (PSP) scale. Neurocognition was measured using Brief Assessment of Cognition in Schizophrenia (BACS-DK), and four subtests from Wechsler Adult Intelligence (WAIS-IV) scale were applied to estimate IQ. The Animated Triangles Task was used to measure implicit ToM, while explicit ToM and social perception were measured by The Awareness and Social Inference Test (TASIT).

Results: Patients with schizophrenia had deficits in implicit ToM and complex social perception compared to their matched controls, but no problems with explicit ToM. Surprisingly, patients with ASD solely had deficits with regard to complex social perception compared to their matched controls. The two patient groups were similar regarding estimated IQ, social functioning and years of education, but differed in age and neurocognition. When adjusting the p-values for age and neurocognitive deficits, both patients groups had similar social cognitive deficits.

Conclusions: Results imply that we compared schizophrenia patients with substantial neurocognitive deficits to a group of high-functioning patients with ASD. However, these two subgroups may have the same level of social cognitive deficits.     

Reduced Mirror Neuron Activity in Schizophrenia and Its Association With Theory of Mind Deficits: Evidence From a Transcranial Magnetic Stimulation Study

Background: The “mirror-neuron system” has been proposed to be a neurophysiological substrate for social cognition (SC) ability. We used transcranial magnetic stimulation (TMS) paradigms to compare putative mirror neuron activity (MNA) in 3 groups: antipsychotic-naive, medicated schizophrenia patients, and healthy comparison subjects. We also explored the association between MNA and SC ability in patients. Methods: Fifty-four consenting right-handed schizophrenia patients (33 antipsychotic naive) and 45 matched healthy comparison subjects completed a TMS experiment to assess putative premotor MNA. We used 4 TMS paradigms of eliciting motor-evoked potentials (MEP) in the right first dorsal interosseous (FDI) muscle. These were applied while the subjects observed a goal-directed action involving the FDI (actual action and its video) and a static image. The difference in the amplitude of the MEP while they observed the static image and the action provided a measure of MNA. Subjects also underwent SC assessments (theory of mind [ToM], emotion processing, and social perception). Results: Two-way repeated measures ANOVA revealed significant group × occasion interaction effect in 3 TMS paradigms, indicating deficient motor facilitation during action observation relative to rest state in antipsychotic-naive schizophrenia patients as compared with the other two groups. Among patients, there were significant direct correlations between measures of MNA and ToM performance. Conclusions: Antipsychotic-naive schizophrenia patients have poorer MNA than medicated patients and healthy controls. Measures of putative MNA had significant and consistent associations with ToM abilities. These findings suggest a possibility of deficient mirror neuron system underlying SC deficits in schizophrenia.Key words: mirror neurons, social cognition, mental state attribution, psychosis, antipsychotic-naive, embodied simulation     

The Social Cognition Psychometric Evaluation Study: Results of the Expert Survey and RAND Panel

Background: In schizophrenia, social cognition is strongly linked to functional outcome and is increasingly seen as a viable treatment target. The goal of the Social Cognition Psychometric Evaluation (SCOPE) study is to identify and improve the best existing measures of social cognition so they can be suitably applied in large-scale treatment studies. Initial phases of this project sought to (1) develop consensus on critical domains of social cognition and (2) identify the best existing measures of social cognition for use in treatment studies. Methods: Experts in social cognition were invited to nominate key domains of social cognition and the best measures of those domains. Nominations for measures were reduced according to set criteria, and all available psychometric information about these measures was summarized and provided to RAND panelists. Panelists rated the quality of each measure on multiple criteria, and diverging ratings were discussed at the in-person meeting to obtain consensus. Results: Expert surveys identified 4 core domains of social cognition—emotion processing, social perception, theory of mind/mental state attribution, and attributional style/bias. Using RAND panel consensus ratings, the following measures were selected for further evaluation: Ambiguous Intentions Hostility Questionnaire, Bell Lysaker Emotion Recognition Task, Penn Emotion Recognition Test, Relationships Across Domains, Reading the Mind in the Eyes Test, The Awareness of Social Inferences Test, Hinting Task, and Trustworthiness Task. Discussion: While it was possible to establish consensus, only a limited amount of psychometric information is currently available for the candidate measures, which underscores the need for well-validated and standardized measures in this area.Key words: schizophrenia, measurement, emotion processing, social perception, theory of mind, attributions, SCOPE     

Disturbances of social cognition in schizophrenia

Social cognition is an ability to perceive socially relevant stimuli and to behave accordingly. It is connected with the processing of information brought about by significant social stimuli. Recently, social cognition is a topic of intensive research in psychology, neurosciences and psychiatry. Processes involved in social cognition include: perception of emotion, input of eye contact, reaction to voice prosody or decision-making in social situations. A particular role is played by the mentalizing capabilities (mind-reading) i.e. ability to interpret behaviour of others by attributing them certain mental states. Such an ability is often conceptualized as the Theory of Mind (ToM). This paper is a review of issues connected with disturbances of social cognition in patients with schizophrenia. Deficits in perceptions of face emotion and disturbances of Theory of Mind function in schizophrenia were discussed with special regard to their potential role as endophenotypes of vulnerability to schizophrenia. Also, relations between social cognition and basic neurocognitive processes were presented, as well as the effect on social cognition of different methods of schizophrenia treatment.     

Cognition sociale dans la schizophrénie et les troubles du spectre de l’autisme : points de convergences et différences fonctionnelles

Introduction

Schizophrenia and autistic spectrum disorder (ASD) are two neurodevelopmental disorders that have different symptom presentations, ages of onset and developmental courses. Both schizophrenia and ASD are characterized by marked deficit in communication, social interactions, affects and emotions. Social cognitive impairments in ASD and schizophrenia were demonstrated separately in both disorders. It was reported that these impairments have direct relation with social deficits of both disorders. The apparent similarity between social cognition impairments in ASD and schizophrenia highlights questions about the existence of common or different neurocognitive mechanisms related to social dysfunctions. In order to examine these questions, the present article provides a comprehensive review of all published studies which directly compare individuals with ASD and schizophrenia on the same cognitive tasks of social cognition.

Insight in schizophrenia: associations with empathy

Many people with schizophrenia (50–80 %) demonstrate impaired insight, something which has been associated with a poorer outcome. Two types of empathy can be distinguished: affective empathy via shared emotions and cognitive empathy, also referred to as Theory of Mind (ToM). ToM can be subdivided into cognitive ToM (knowledge about beliefs of other people via perspective taking) and affective ToM (knowledge about other people’s emotions via perspective taking). Recent studies show a relationship between Theory of Mind (ToM) and insight. However, the relationship between affective empathy and insight in schizophrenia was not examined previously. This was the aim of the present study. We expected that affective empathy would show a stronger relationship with insight than both cognitive and affective ToM. We assessed forty-six patients with a diagnosis of schizophrenia, and fifty-three healthy controls were assessed with a test battery consisting of tests of social cognition (a self-rating scale for affective empathy, a ToM task assessing both cognitive and affective ToM, and two tests of emotion perception), verbal memory, executive functioning, psychomotor speed, and intelligence. Insight was assessed with item G12 of the PANSS-interview. A regression equation showed that affective empathy made the strongest unique contribution to insight, followed closely by affective ToM. Together, they explained 45 % of the variance in insight. None of the other independent variables made a unique contribution to the prediction of insight. Both affective ToM and affective empathy are associated with insight in schizophrenia. Being able to take empathize with other peoples feeling at both the affective and cognitive level may enhance insight in schizophrenia.     

A review of emotion deficits in schizophrenia

Emotion deficits in schizophrenia have been described since the time of Kraepelin. However, no comprehensive review of clinical emotion studies has ever been conducted. In this work, studies that used diagnostic criteria and were published in English were selected from an extensive PubMed search. Fifty-five studies on emotion expression repeatedly showed that individuals with schizophrenia (IWSs) display fewer overt expressions than nonpatient comparison subjects (NCSs) in verbal, facial, and acoustic channels. No clear differences were found between IWSs and depressed subjects. Sixty-nine studies examined emotion experience in schizophrenia. IWSs report higher anhedonia, and they tend to show more negative emotions in real-life event studies. In evocative studies, they report a similar degree of pleasantness and a similar or higher degree of unpleasantness. From 110 studies, it can be concluded that emotion recognition is impaired in schizophrenia in all channels. These deficits in social perception are correlated with neurocognitive deficits and some social skills. IWSs show dysfunction in the three domains of emotion expression, emotion experience, and emotion recognition, and these dysfunctions appear to be independent of each other across domains. These deficits in basic emotion processing may be linked to psychopathology and functional outcomes.     

Could schizophrenic subjects improve their social cognition abilities only with observation and imitation of social situations?

Schizophrenics display impairments in domains of social cognition such as theory of mind and emotion recognition. Recent studies, showing that the relationship of social cognition abilities with functional outcome is more significant than other neuro-cognitive functions, have considered these abilities as a target for intervention research. This article describes preliminary data from a new group-based study focused on Emotion and ToM Imitation Training (ETIT), an imitation treatment aimed at improving social cognition and social functioning in schizophrenia.

In the present study, 16 outpatients with schizophrenia completed ETIT assessment and were compared with 17 outpatients who participated to a Problem Solving Training group. Participants were assessed at pre- and post-test on measures of emotion recognition, theory of mind, cognition, flexibility and social functioning. We compared the rehabilitation training effects on neuro-physiological activation through the event-related potentials (ERPs) method, which was recorded pre- and post-rehabilitation training. The results showed that when compared to the control group, ETIT participants improved on every social cognitive measure and showed better social functioning at post-test. Improvement in social cognition, in particular in emotion recognition, is also supported by ERP responses: we recorded an increase in electroactivity of medio-frontal areas only after ETIT treatment. Action observation and imitation could be regarded as a new frontier in rehabilitation.     

Social cognition as a mediator of cognition and outcome among deaf and hearing people with schizophrenia

It has been suggested in the research literature that facial affect processing (FAP) and theory of mind (ToM) are both potential mediators of the well-established relationship between cognition and functional outcome among people with schizophrenia. The current project tests the mediating potency of these two domains of social cognition among deaf and hearing people with schizophrenia. Sixty-five people (34 deaf, 31 hearing) were assessed using measures of verbal and visual memory, attention, visual processing, FAP, and ToM. The results suggest that each domain of cognition, save vigilance, exerts an effect on functional outcome indirectly through its influence on social cognition. The patterns of mediation varied when the samples were broken down by hearing status and analyzed separately. Namely, the cognitive tasks directly involving linguistic ability (early visual processing [EVP] and word memory) were best mediated by social cognition for hearing subjects. For deaf subjects, the nonlinguistic cognitive tasks (e.g., visual-spatial memory-recall and copy [VSM-recall and VSM-copy]) were best mediated by social cognition. While FAP and ToM were equally effective as mediators for hearing subjects, FAP was a more potent mediator than ToM for deaf subjects. This study extends prior work in the area of social cognition and schizophrenia and indicates that the development of cognitive rehabilitation strategies should include not only interventions targeting specific cognitive abilities, such as attention and memory, but should include an emphasis on social-cognitive domains, including FAP and ToM. Further, deaf and hearing subjects may benefit from interventions addressing aspects of cognition that support linguistic ability, especially as they relate to social cognition.     

Reduction in Tonal Discriminations Predicts Receptive Emotion Processing Deficits in Schizophrenia and Schizoaffective Disorder

Introduction: Schizophrenia patients show decreased ability to identify emotion based upon tone of voice (voice emotion recognition), along with deficits in basic auditory processing. Interrelationship among these measures is poorly understood. Methods: Forty-one patients with schizophrenia/schizoaffective disorder and 41 controls were asked to identify the emotional valence (happy, sad, angry, fear, or neutral) of 38 synthesized frequency-modulated (FM) tones designed to mimic key acoustic features of human vocal expressions. The mean (F0M) and variability (F0SD) of fundamental frequency (pitch) and absence or presence of high frequency energy (HF500) of the tones were independently manipulated to assess contributions on emotion identification. Forty patients and 39 controls also completed tone-matching and voice emotion recognition tasks. Results: Both groups showed a nonrandom response pattern (P < .0001). Stimuli with highest and lowest F0M/F0SD were preferentially identified as happy and sad, respectively. Stimuli with low F0M and midrange F0SD values were identified as angry. Addition of HF500 increased rates of angry and decreased rates of sad identifications. Patients showed less differentiation of response across frequency changes, leading to a highly significant between-group difference in response pattern to maximally identifiable stimuli (d = 1.4). The differential identification pattern for FM tones correlated with deficits in basic tone-matching ability (P = .01), voice emotion recognition (P < .001), and negative symptoms (P < .001). Conclusions: Specific FM tones conveyed reliable emotional percepts in both patients and controls and correlated highly with deficits in ability to recognize information based upon tone of voice, suggesting significant bottom-up contributions to social cognition and negative symptom impairments in schizophrenia.     

An Event-Related Potential Investigation of Early Visual Processing Deficits During Face Perception in Youth at Clinical High Risk for Psychosis

Impairments in early visual face perception are well documented in patients with schizophrenia. Specifically, event-related potential (ERP) research in patients with schizophrenia has demonstrated deficits in early sensory processing of stimulus properties (P1 component) and the structural encoding of faces (N170 component). However, it is not well understood if similar impairments are present in individuals at clinical high risk (CHR) for psychosis (ie, those in the putative prodromal stage of the illness). Thus, it is unknown if face perception deficits are the result of illness onset or are present in the high-risk period for the illness. The present study used the ERP technique to examine neural activation when viewing facial emotion expressions and objects in 44 CHR and 47 control adolescents and young adults (N = 91). P1 amplitude was similar across groups, indicating that early sensory processing impairments did not substantially contribute to face perception deficits in CHR youth. CHR youth exhibited reduced N170 amplitude compared to controls when viewing faces but not objects, implicating a specific deficit in the structural encoding of faces rather than a general perceptual deficit. Further, whereas controls demonstrated the expected face-selective N170 effect (ie, larger amplitude for faces than objects), CHR youth did not, which suggests that facial emotion expressions do not elicit the expected preferential perceptual processing for critical social information in individuals at CHR for psychosis. Together, these findings provide valuable information regarding the specific impairments contributing to face perception deficits in the high-risk period where treatment stands to aid in preventing illness progression.     

Are Deficits in the Decoding of Affective Cues and in Mentalizing Abilities Independent?

It has been hypothesized that deficits in theory of mind (ToM) and emotion recognition abilities in subjects with autisticlike disorders are independent. We examined the relationships between deficits in the various social cognitive domains in children with an autistic disorder (N = 20), in children with a pervasive developmental disorder not otherwise specified (PDDNOS) (N = 20), and in psychiatric control (N = 20) and normal children (N = 20). The clinical groups were matched person-to-person on age and verbal IQ. The clinical children were 8–18 years old, the normal children 8–13 years old. The test battery included tasks for the matching and the context recognition of emotional expressions, and a set of first- and second-order ToM tasks. ToM and emotion recognition functioning proved to be better integrated in the non-PDD children than in the PDD children, but also in the PDD children significant correlations were found between ToM and emotion recognition measures.     

Theory of mind in schizophrenia: clinical aspects and empirical research

The term Theory of Mind (ToM) refers to the capacity to infer one's own and other persons' mental states. A substantial body of research has highlighted impaired ToM in a variety of neuropsychiatric disorders, including schizophrenia. There is good empirical evidence that ToM is specifically impaired in schizophrenia and that many psychotic symptoms--for instance, delusions of alien control and persecution--may best be understood in light of a disturbed capacity in patients to relate their own intentions to executing behavior, and to monitor others' intentions. However, it is still under debate if impaired ToM in schizophrenia is a state- or trait marker and whether patients could benefit from cognitive training in this domain. Recently, research has not only emphasized social cognitive deficits in patients, but has also focussed on interactions between ToM with language and other cognitive functions. Furthermore, interest in subprocesses of social cognition in psychotic spectrum disorders (e. g. schizotypy) is growing. The aim of this article is to line out clinical aspects of disturbed social cognition, to clarify terms used in this context as well as to present the latest research approaches into social cognition deficits.     

Social Cognition and Interaction Training (SCIT) for inpatients with schizophrenia spectrum disorders: preliminary findings

Individuals with schizophrenia exhibit consistent deficits in social cognition such as emotion perception, attributional style, and theory of mind, which may be targets of psychosocial treatments. Previous intervention studies have typically focused on only one aspect of social cognition and have not assessed generalization of treatment to improvements in social functioning. This paper describes preliminary data from a new group-based treatment, Social Cognition and Interaction Training (SCIT), aimed at improving social cognition in schizophrenia. Eighteen inpatients with schizophrenia spectrum disorders completed SCIT and were compared with 10 inpatients who completed a coping skills group. Participants were assessed at pre-test and post-test on measures of emotion and social perception, theory of mind, attributional style (e.g., blame, hostility, and aggression), cognitive flexibility, and social relationships. We also collected data on the frequency of aggressive incidents on the treatment ward. The results showed that compared to the control group, SCIT participants improved on all of the social cognitive measures and showed better self-reported social relationships and fewer aggressive incidents on the treatment unit at post-test. Importantly, this change was independent of changes in clinical symptoms over time and supports the unique role of SCIT in improving social cognitive deficits in schizophrenia.     

Alterations of theory of mind network activation in chronic cannabis users

Chronic cannabis use is associated with cognitive impairment and has been identified as a risk factor for schizophrenia. Patients with schizophrenia show profound deficits in social cognition such as the ability to attribute mental states to others, referred to as "theory of mind" (ToM). Aberrant activation of the ToM network has been demonstrated across different phases of schizophrenia, including at-risk stages. Accordingly, we aimed to investigate the ToM network in chronic cannabis users. Fifteen cannabis users received functional brain imaging during performance of a ToM cartoon story task. Findings were compared with 14 control subjects. Cannabis users showed less activation in the left parahippocampal gyrus, the right precuneus and cuneus, but greater activation in the left cuneus and the right anterior cingulate gyrus compared to healthy controls. These activation patterns resemble those found in at-risk populations, suggesting that cannabis use can affect the processing of social information similar to other risk factor constellations for psychosis.