Cannabis and Neurological Soft Signs in Schizophrenia: Absence of Relationship and Influence on Psychopathology

Abstract

Background: Cannabis is a possible risk factor for the onset of schizophrenia and can induce neurocognitive, behavioural and motor co-ordination alterations. The aim of this study was to evaluate the role of cannabis in the occurrence of neurological soft signs (NSS) and, considering that this drug has been related to positive symptoms, whereas NSS have been linked to negative symptoms, we also examined the role of clinical features. Methods: The study investigated NSS in 25 male cannabis-consuming and 25 male non-consuming schizophrenic patients, using the Neurological Evaluation Scale. Clinical features were studied using SANS and SAPS. Results: Significant differences emerged after comparison analysis, with more NSS in non-consuming patients. The SANS subscales Alogia and Anhedonia-asociality were also statistically significant in this group of patients. Discussion: If non-consuming patients show a higher incidence of both NSS and negative symptoms, which, according to the literature, seem to be associated, then these findings suggest that NSS are relatively independent from cannabis, but not from clinical features.

Deficit of Executive Functions in Schizophrenia: Relationship to Neurological Soft Signs and Psychopathology

“…NSS include difficulty in right and left discrimination, impairment in coordination and in complex motor sequencing, sensorial deficits and developmental reflexes such as grasp and suck reflexes. On a clinical level, NSS appear to be related to a chronic course of the illness [22], thought disorders [23], negative symptoms [24], poor response to neuroleptic treatment [25] and less prevalence of cannabis abuse [26]. Several studies indicate an increased prevalence of NSS also in drug-free schizophrenic patients [27,28] and in individuals at high risk of schizophrenia before the onset of their illness [29]: these findings suggest the independence of the NSS from neurological abnormalities related to neuroleptic treatment.…”

Anhedonia and Substance-Related Symptoms in Detoxified Substance-Dependent Subjects: A Correlation Study

“…The Scale for the Assessment of Negative Symptoms (SANS) by Andreasen [30] was used in schizophrenic patients with or without abuse of cannabis [31][32][33] . The Bech-Rafaelsen Melancholia Scale (BRMS) [34] was administered not only to melancholic patients but also to acute schizophrenic subjects, rating the latent dimension of depressive and negative symptomatology and showing a positive correlation with SANS [35] .…”

Revisión sobre el consumo de cannabis como factor de riesgo de la esquizofrenia

“…En un seguimiento realizado a 232 sujetos tras un primer episodio psicótico, se observó la presencia de más síntomas positivos en los consumidores de drogas, la mayoría consumidores de cannabis (Buhler, Hambrecht, Loffler, van der Heiden y Hafner, 2002). Igualmente, otros autores señalaron que los sujetos con esquizofrenia que presentan consumo de cannabis tienen más síntomas psicóticos positivos ( Bersani, Orlandi, Gherardelli y Pancheri, 2002;Margolese, Negrete, Tempier y Gill, 2006) y un metaanálisis confirma estos hallazgos (Talamo, Centorrino, Tondo, Dimitri, Hennen y Baldessarini, 2006).…”

“…Algunos autores apoyan una menor presencia de estos entre los adictos (Bersani, et al, 2002;Compton, Furman y Kaslow, 2004) o, al menos, con menos intensidad (Buhler, et al, 2002). Nosotros también observamos una menor severidad de los síntomas negativos en los dependientes de cannabis, aunque señalamos un posible efecto diferencial del efecto de cada droga, así el consumo de tabaco y de cannabis se asoció con menos síntomas negativos pero, por el contrario, el de alcohol se asoció con una mayor presencia de estos (Arias, et al, 2002a).…”

“…Hay que señalar que, aunque con frecuencia se observa que el consumo de cannabis es más precoz que la esquizofrenia, tenemos que considerar la distinta historia natural de cada trastorno. De igual forma, hasta un tercio de los psicóticos comienza el consumo de cannabis posteriormente al inicio de su cuadro (Bersani, et al, 2002).…”