History of Lifetime Cannabis Use Is Associated with Better Cognition and Worse Real-World Functioning in Schizophrenia Spectrum Disorders

Abstract

Background: Data on associations between cannabis use and psychopathology, cognition and functional impairment in schizophrenia spectrum disorders (SSD) is controversial. Objectives: To examine the effect of cannabis on psychopathology, cognition and real-world functioning in SSD patients. Method: Naturalistic cross-sectional study, 123 clinically stable SSD outpatients. Assessment: demographic and clinical data, psychometric evaluation: Positive and Negative Syndrome, Hamilton Depression Rating, Clinical Global Impression (CGI), Personal and Social Performance and Screen for Cognitive Impairment in Psychiatry (SCIP) scales. Patients were classified as cannabis user patients (CUP) and non cannabis user patients (NCUP) according to self-report, both lifetime and last year. Statistical analysis: chi-square, Student t test, ANOVA (Duncan post hoc), and general linear model analysis for adjusting for antipsychotic doses. Results: Mean age 40.75, 66.7% male, single (66.7%), prior hospital admissions 2.75, mean length of illness 13.85 years. 53.7% were lifetime cannabis users and 8.9% last year users. Lifetime CUP had more hospitalizations (p = 0.013) at a younger age (p = 0.002), and showed better cognitive functioning globally (CGI-C: p = 0.045) and on working memory and processing speed (SCIP-2: p = 0.039; SCIP-5: p = 0.033) and worse functioning in socially useful activities (p = 0.014) than NCUP. All these differences remained after adjusting for antipsychotic doses. Last year cannabis users had worse mood (Hamilton Depression Rating Scale 9.66 vs. 5.64; p = 0.002), but this difference disappears when adjusting for antipsychotic doses. Conclusions: Lifetime cannabis use is associated with better working memory and processing speed and worse real-world functioning in the area of socially useful activities in patients with schizophrenia-related disorders. Clinicians should, therefore, be aware of it to provide patient-centred care in their daily clinical practice.

Introduction to JINS Special Issue: Clarifying the Complexities of Cannabis and Cognition

“…Filbey et al 2021;Schacht et al, 2012;Taurisano et al, 2021), psychiatric comorbidities (e.g. Bogaty et al, 2018;Menendez-Miranda et al, 2019;Wallace et al, 2019), and lifestyle factors that influence brain health (Lisdahl et al, 2014). For the latter, this Special Issue includes an article by Sullivan and colleagues reporting novel relationships between aerobic fitness, cannabis use and brain volume in healthy adolescents and young adults.…”

Consumo de cannabis y alteraciones cognitivas en esquizofrenia y primeros episodios psicóticos

“…Las tipos de memoria evaluados en los diferentes estudios han sido diversos, memoria visual (Sanchez-Torres et al, 2013;Yucel et al, 2012), verbal (Rabin et al, 2017;Sanchez-Torres et al, 2013;Schnell et al, 2009;Setien-Suero et al, 2018), episódica (Mallet, Ramoz, Le Strat, Gorwood, y Dubertret, 2017), inmediata (Nunez et al, 2016), de trabajo (Gonzalez-Pinto et al, 2016;Meijer et al, 2012;Menendez-Miranda et al, 2019;Nunez et al, 2016;Schnell et al, 2009;Yucel et al, 2012) o a largo plazo (Nunez et al, 2016). Asimismo, los datos de los mismos no son concluyentes.…”

“…Asimismo, los datos de los mismos no son concluyentes. En pacientes con esquizofrenia con historia de consumo de cannabis en algunos casos se ha observado una mejor adquisición de conocimiento (Meijer et al, 2012), mejor desempeño en tareas de memoria (DeRosse et al, 2010;Menendez-Miranda et al, 2019), incluso pacientes que habían sido consumidores graves antes del inicio de la enfermedad parecían mostrar una mejor memoria episódica (Mallet et al, 2017). Sin embargo, en hermanos de pacientes con esquizofrenia una historia de consumo de cannabis a lo largo de la vida se ha asociado con un efecto negativo en la memoria declarativa, tanto visual como verbal (Sanchez-Torres et al, 2013).…”

“…El consumo de cannabis a lo largo de la vida en personas con trastornos psicóticos (Power et al, 2015) o esquizofrenia (Menendez-Miranda et al, 2019) también se ha asociado con la velocidad de procesamiento, pero de nuevo se observan resultados dispares, mientras que unos observan un mejor desempeño (DeRosse et al, 2010; Rabin, Zakzanis, Daskalakis, y George, 2013), otros encuentran un peor rendimiento (Meijer et al, 2012). Sin embargo, una vez que se controlan ciertas variables confusoras (edad, edad de inicio de la enfermedad, CI premórbido y el índice socioeconómico) desaparece la asociación entre cannabis y velocidad de procesamiento (Power et al, 2015).…”

Investigating repetitive transcranial magnetic stimulation on cannabis use and cognition in people with schizophrenia

“…Globally, 21 million people suffer from schizophrenia 1 . The high prevalence of cannabis use in schizophrenia is well-established, with lifetime rates of 53.7% 2 . A meta-analysis found that 25% of people with schizophrenia have cannabis use disorder (CUD) 3 compared to ~3% in general population 4 .…”