Substance abuse and suicidality in schizophrenia: a common risk factor linked to impulsivity.

Lifetime substance abuse comorbidity is frequent in schizophrenic patients, but the clinical correlates remain unclear. We have explored the chronological relations between substance abuse and course of schizophrenia, and compared several clinical characteristics and personality dimensions in 50 schizophrenic patients with or without lifetime substance abuse or dependence. Abuse occurred mainly after the first prodromal symptoms and just before the first psychotic episode. Substance-abusing patients were not different from non-substance-abusing patients on the Chapman Physical Anhedonia Scale, PANSS total score, negative subscore or depression item, CGI, treatment response and demographic variables. In contrast, substance-abusing patients had higher scores on the Barratt Impulsivity Scale (total, cognitive and non-planning scores) and had attempted suicide more often. In patients with schizophrenia, as in the general population, substance abuse or dependence appears associated with higher impulsivity and suicidality. High impulsivity could facilitate substance abuse as a maladaptive behavior in response to prodromal symptoms, precipitating the onset of a characterized psychosis.

Impairment of predictive saccades in schizophrenia.

Using infrared oculography, we compared saccades toward predictable and pseudo-random visual targets in 19 neuroleptic-free patients with schizophrenia (including 13 neuroleptic-naïve patients) and in 29 age- and gender-matched healthy volunteers. Externally driven saccades were not different between patients and controls, whether or not the target was predictable. Anticipated saccades were specifically less accurate in the patients compared to the controls. The difference between primary gain of anticipated and non-anticipated saccades was markedly higher in the patients compared to controls (p=0.003). These results point to a deficit in the early step of internally driven oculomotor planning in schizophrenia.

Validation and factorial structure of a standardized neurological examination assessing neurological soft signs in schizophrenia.

Although neurological soft signs (NSS) have been consistently reported in patients with schizophrenia, their clinical relevance, the actual impact of treatment or their evolution during the disease are not well clarified, possibly because of methodological limitations of the available tools. We have developed a new standardized examination integrating the assessment of 23 NSS selected from the literature and the rating of well-validated scales for assessment of extra-pyramidal symptoms. We examined 161 subjects (controls, n=48; patients with schizophrenia, n=95; or recurrent mood disorder, n=18). Half of the patients were neuroleptic-free. Schizophrenic patients had significantly higher total score (14. 6+/-8) than mood disorder patients (12.0+/-7) and controls (5.0+/-2). Internal consistency (Cronbach's alpha=0.85) and inter-rater reliability were good. Principal component analysis found five consistent factors ('motor coordination', 'motor integrative function', 'sensory integration', 'involuntary movements or posture', 'quality of lateralization'). This scale thus confirmed a factorial structure in agreement with the conceptual areas of interest explored by NSS and should be a useful tool for assessment of the different dimensions of neurological dysfunction in schizophrenia.

[Clinical dimensions and visually guided saccades in schizophrenia]. / Dimensions cliniques et saccades visuellement guidées dans la schizophrénie.

Eye movement anomalies are more frequent in schizophrenic patients than in healthy subjects. This study deals with visually guided saccadic eye movements in seventeen schizophrenic patients [ten untreated (neuroleptic-naive or free), seven treated patients] and their correlations between symptoms presented by patients and oculomotor performances. There was no significant difference between the patients and the control group in visually guided saccades tasks. However, negative correlations between oculomotor performance and positive or disorganisation symptomatology were found. Thus, although no major oculomotor dysfunction in response to external stimulus was seen in schizophrenic patients, some symptoms were linked to oculomotor performance impairment. Thus psychiatric symptoms might share some common cerebral circuits which those involved in oculomotor tasks.