Assessing cognitive-related disability in schizophrenia: Reliability, validity and underlying factors of the evaluation of cognitive processes involved in disability in schizophrenia scale.

PURPOSE: We have developed a new scale that assesses disability caused by cognitive impairments in schizophrenia, in order to evaluate the functional impact of schizophrenia and help the prescription of rehabilitation interventions. The aim of the study was to assess its psychometrical properties. MATERIALS AND METHODS: Mental healthcare professionals and relatives of individuals with schizophrenia developed and rated the evaluation of cognitive processes involved in disability in schizophrenia scale, which included 13 items. Its construct validity was assessed through a factorial analysis; its concurrent validity was evaluated based on ecological outcomes, its convergent validity was tested against the World Health Organization Disability Assessment Schedule (WHODAS II), and its reliability was estimated based on internal consistency and inter-rater reliability. RESULTS: Overall, 215 patients were included. Our findings supported a two-factor structure which accounted for 46% of the variance. The internal consistency and inter-rater reliability were good. The convergent validity showed a strong correlation with the WHODAS II. The concurrent validity showed strong relationships with work status, independent living, level and adequacy of institutional care. CONCLUSIONS: The good psychometric properties of the scale suggest a role for this tool in assessing schizophrenia-related disability and evaluating the need for cognitive remediation. Implication for Rehabilitation Schizophrenia is a chronic disorder leading to a severe psychiatric handicap. The scale showed good psychometric properties in individuals with schizophrenia and severe psychiatric disability. The scale is easy and quick to administer (about 15 min). The scale may help to identify targets for rehabilitation interventions in individuals with schizophrenia.

Clinical practice of rTMS reveals a functional dissociation between agency and hallucinations in schizophrenia.

We report here the case of a hospitalized 11 year-old boy (YP) with a positive diagnosis of 'Childhood Onset Schizophrenia'. YP experienced verbal-auditory hallucinations, a delusion of alien control and hetero-aggressive behaviour. Antipsychotic drugs were unsuccessful and furthermore provoked severe acute dystonia. fMRI-guided rTMS applied over several cortical regions provided the means to reveal for the first time a functional dissociation between auditory-verbal hallucinations and agency. These results demonstrate the efficacy of rTMS for young patients suffering from drug-resistant hallucinations but they furthermore question the physiopathology of the hallucinatory process by suggesting that agency and hallucinations may be sub-served by different neural networks.

A pre-reflective indicator of an impaired sense of agency in patients with Schizophrenia.

In schizophrenia, passivity phenomenon are clinically related to an abnormal sense of agency, which has been experimentally studied through self-recognition tasks. However, Tsakiris et al. (Cognition 96(3):215-231, 2005) have recently shown in healthy controls that the sense of agency is distinct from self-recognition abilities. We propose a simple motor task to obtain an implicit indicator of the working status of the pre-reflective sense of agency in schizophrenia. Collision dynamics gave us the means to further dissociate agency from motor prediction. Twenty-four patients and a group of matched controls used a hand-held object to stop the fall of a pendulum that was released either by the Subject (task S) or by the Experimenter (task E). The objective indicator of the sense of agency was taken as the efficiency difference between tasks S and E, before the availability of afferent information from collision. Qualitative feedback was provided to assess the top-down effect of explicit information. Motor prediction was as accurate in patients as in controls in tasks E and S. Controls were more efficient in S than in E. Patients revealed similar efficiency levels in both tasks. Qualitative feedback helped but did not affect the efficiency difference between tasks. Our results suggest an impairment of a pure efferent-driven sense of agency in schizophrenia, which is (1) distinct from motor prediction and (2) not under voluntary control. The abnormal judgments previously reported in schizophrenia for self-recognition abilities might be the consequence of a low order deficit of a pre-reflective sense of agency.