Skip to main content Accessibility help
×
Home
Hostname: page-component-55597f9d44-mm7gn Total loading time: 0.446 Render date: 2022-08-10T01:19:49.243Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "useRatesEcommerce": false, "useNewApi": true } hasContentIssue true

Cannabis use and neuropsychological performance in healthy individuals and patients with schizophrenia

Published online by Cambridge University Press:  17 December 2009

K. E. Scholes*
Affiliation:
Centre for Clinical Research in Neuropsychiatry, Graylands Hospital, Perth, WA, Australia School of Medicine and Pharmacology, University of Western Australia, Perth, WA, Australia
M. T. Martin-Iverson
Affiliation:
Centre for Clinical Research in Neuropsychiatry, Graylands Hospital, Perth, WA, Australia School of Medicine and Pharmacology, University of Western Australia, Perth, WA, Australia
*
*Address for correspondence: K. E. Scholes, Centre for Clinical Research in Neuropsychiatry, Post Office Private Bag No. 1, Claremont, WA, 6910, Australia. (Email: kirsty.scholes@health.wa.gov.au)

Abstract

Background

The effects of cannabis use on neuropsychological indices that show characteristic disturbances in schizophrenia are unclear. The effect of cannabis use on these cognitive functions is of particular interest given the hypothesized association between cannabis use and schizophrenia. Therefore, this study aimed to examine the effects of cannabis use on attentional control, working memory and executive functioning, in both healthy individuals and patients with schizophrenia.

Method

Neuropsychological performance was assessed in 36 cannabis users who were otherwise healthy, 35 healthy non-users, 22 cannabis-using patients with schizophrenia, and 49 non-using patients with schizophrenia. Participants were administered the Stroop task, the letter–number sequencing and spatial span subtests of the Wechsler Memory Scale, and the Wisconsin Card Sorting Test (WCST).

Results

Patients with schizophrenia (both cannabis users and non-users) showed significantly poorer performance across all neuropsychological tasks, relative to controls; however, there were no significant differences between schizophrenic cannabis users and schizophrenic non-users on any measures, with the exception of increased non-perseverative errors on the WCST in cannabis-using patients. Similarly, healthy cannabis users showed no significant differences from healthy non-users in any of the cognitive domains, with the exception of a schizophrenic-like increase in perseveration on the WCST.

Conclusions

Amongst both healthy individuals and patients with schizophrenia there appears to be little difference in cognitive performance between cannabis users and non-users, suggesting that cannabis use has only subtle effects on the neurocognitive performance indices assessed here, which have been well established to be disturbed in schizophrenia.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Addington, J, Addington, D (1997). Substance abuse and cognitive functioning in schizophrenia. Journal of Psychiatry and Neuroscience 22, 99–104.Google Scholar
Amorim, P, Lecrubier, Y, Weiller, E, Hergueta, T, Sheehan, BD (1998). DSM-III-R psychotic disorders: procedural validity of the Mini International Neuropsychiatric Interview (MINI). Concordance and causes for discordance with the CIDI. European Psychiatry 13, 2634.CrossRefGoogle ScholarPubMed
Andreasen, NC (1994). The mechanisms of schizophrenia. Current Opinion in Neurobiology 3, 245251.CrossRefGoogle Scholar
Atkins, M, Burgess, A, Bottomley, C, Riccio, M (1997). Chlorpromazine equivalents: a consensus of opinion for both clinical and research applications. Psychiatric Bulletin 21, 224226.CrossRefGoogle Scholar
Bolla, KI, Brown, K, Eldreth, D, Tate, K, Cadet, JL (2002). Dose-related neurocognitive effects of marijuana use. Neurology 59, 13371343.CrossRefGoogle ScholarPubMed
Bustini, M, Stratta, P, Daneluzzo, E, Pollice, R, Prosperini, P, Rossi, A (1999). Tower of Hanoi and WCST performance in schizophrenia: problem-solving capacity and clinical correlates. Journal of Psychiatric Research 33, 285290.CrossRefGoogle Scholar
Castle, DJ, Jablensky, A, McGrath, JJ, Carr, V, Morgan, V, Waterreus, A, Valuri, G, Stain, H, McGuffin, P, Farmer, A (2006). The diagnostic interview for psychoses (DIP): development, reliability and applications. Psychological Medicine 36, 6980.CrossRefGoogle ScholarPubMed
Chey, J, Lee, J, Kim, Y, Kwon, S, Shin, Y (2002). Spatial working memory span, delayed response and executive function in schizophrenia. Psychiatry Research 110, 259271.CrossRefGoogle Scholar
Cleghorn, JM, Kaplan, RD, Szechtman, B, Szechtman, H, Brown, GM, Franco, S (1991). Substance abuse and schizophrenia: effect on symptoms but not on neurocognitive function. Journal of Clinical Psychiatry 52, 2630.Google Scholar
Coulston, CM, Perdices, M, Tennant, CC (2007). The neuropsychological correlates of cannabis use in schizophrenia: lifetime abuse/dependence, frequency of use, and recency of use. Schizophrenia Research 96, 169184.CrossRefGoogle Scholar
Curran, HV, Brignell, C, Fletcher, S, Middleton, P, Henry, J (2002). Cognitive and subjective dose–response effects of acute oral Δ9-tetrahydrocannabinol (THC) in infrequent cannabis users. Psychopharmacology 164, 6170.CrossRefGoogle Scholar
Degenhardt, L, Hall, W (2006). Is cannabis use a contributory cause of psychosis? Canadian Journal of Psychiatry 51, 556565.CrossRefGoogle Scholar
Degenhardt, L, Hall, W, Lynskey, M (2003 a). Exploring the association between cannabis use and depression. Addiction 98, 14931504.CrossRefGoogle ScholarPubMed
Degenhardt, L, Hall, W, Lynskey, M (2003 b). Testing hypotheses about the relationship between cannabis use and psychosis. Drug and Alcohol Dependence 71, 3748.CrossRefGoogle ScholarPubMed
D'Souza, DC, Perry, E, MacDougall, L, Ammerman, Y, Cooper, T, Wu, Y, Braley, G, Gueorguieva, R, Krystal, JH (2004). The psychotomimetic effects of intravenous delta-9-tetrahydrocannabinol in healthy individuals: implications for psychosis. Neuropsychopharmacology 29, 15581572.CrossRefGoogle Scholar
Egan, MF, Goldberg, TE, Kolachana, BS, Callicott, JH, Mazzanti, CM, Straub, RE, Goldman, D, Weinberger, DR (2001). Effect of COMT Val108/158 Met genotype on frontal lobe function and risk for schizophrenia. Proceedings of the National Academy of Sciences USA 98, 69176922.CrossRefGoogle ScholarPubMed
Eldreth, D, Matochik, JA, Cadet, JL, Bolla, KI (2004). Abnormal brain activity in prefrontal brain regions in abstinent marijuana users. NeuroImage 23, 914920.CrossRefGoogle ScholarPubMed
El Hamaoui, Y, Elyazaji, M, Yaalaoui, S, Rachidi, L, Saoud, M, d'Amato, T, Moussaoui, D, Dalery, J, Battas, O (2006). Wisconsin card sorting task in patients with schizophrenia and their siblings. Canadian Journal of Psychiatry 51, 4854.Google ScholarPubMed
Elvevåg, B, Goldberg, TE (2000). Cognitive impairment in schizophrenia is the core of the disorder. Critical Reviews in Neurobiology 14, 121.CrossRefGoogle ScholarPubMed
Everett, J, Lavoie, K, Gagnon, JF, Gosselin, N (2001). Performance of patients with schizophrenia on the Wisconsin Card Sorting Test (WCST). Journal of Psychiatry and Neuroscience 26, 123130.Google Scholar
Evins, AE, Deckersbach, T, Cather, C, Freudenreich, O, Culhane, MA, Henderson, DC, Green, MF, Schoenfeld, DA, Rigotti, NA, Goff, DC (2005). Independent effects of tobacco abstinence and bupropion on cognitive function in schizophrenia. Journal of Clinical Psychiatry 66, 11841190.CrossRefGoogle Scholar
George, TP, Vessicchio, JC, Termine, A, Sahady, DM, Head, CA, Pepper, WT, Kosten, TR, Wexler, B (2002). Effects of smoking abstinence on visuospatial working memory function in schizophrenia. Neuropsychopharmacology 26, 7585.CrossRefGoogle Scholar
Gold, JM, Carpenter, C, Randolph, C, Goldberg, TE, Weingerger, DR (1997). Auditory working memory and Wisconsin card sorting test performance in schizophrenia. Archives of General Psychiatry 54, 159165.CrossRefGoogle Scholar
Golden, CJ, Freshwater, SM (2002). Stroop Color and Word Test: A Manual for Clinical and Experimental Uses. Stoelting Co: Chicago.Google Scholar
Gruber, SA, Yurgelun-Todd, D (2005). Neuroimaging of marijuana smokers during inhibitory processing: a pilot investigation. Cognitive Brain Research 23, 107118.CrossRefGoogle ScholarPubMed
Haney, M, Hart, CL, Vosburg, SK, Nasser, J, Bennett, A, Zubaran, C, Foltin, RW (2004). Marijuana withdrawal in humans: effects of oral THC or divalproex. Neuropsychopharmacology 29, 158170.CrossRefGoogle ScholarPubMed
Haney, M, Ward, AS, Comer, SD, Foltin, RW, Fischman, MW (1999 a). Abstinence symptoms following oral THC administration to humans. Psychopharmacology 141, 385394.CrossRefGoogle Scholar
Haney, M, Ward, AS, Comer, SD, Foltin, RW, Fischman, MW (1999 b). Abstinence symptoms following smoked marijuana in humans. Psychopharmacology 141, 395404.CrossRefGoogle ScholarPubMed
Hart, CL, Ward, AS, Haney, M, Comer, SD, Foltin, RW, Fischman, MW (2002). Comparison of smoked marijuana and oral Δ9-tetrahydrocannabinol in humans. Psychopharmacology 164, 407415.CrossRefGoogle ScholarPubMed
Hartman, M, Steketee, MC, Silva, S, Lanning, K, Andersson, C (2003). Wisconsin Card Sorting Test performance in schizophrenia: the role of working memory. Schizophrenia Research 63, 201217.CrossRefGoogle ScholarPubMed
Harvey, MA, Sellan, JD, Porter, RJ, Frampton, CM (2007). The relationship between non-acute adolescent cannabis use and cognition. Drug and Alcohol Review 26, 309319.CrossRefGoogle ScholarPubMed
Heaton, RK, Chelune, GJ, Talley, JL, Kay, GG, Curtiss, G (1993). Wisconsin Card Sorting Test Manual. Revised and Expanded. Psychological Assessment Resources Inc.: Lutz, FL.Google Scholar
Heaton, RK, PAR, Staff (2005 a). WCST: Computer Version 4 Scoring Program: Research Edition. Psychological Assessment Resources Inc.: Lutz, FL.Google Scholar
Heaton, RK, PAR, Staff (2005 b). WCST: Computer Version 4: Research Edition. Psychological Assessment Resources Inc.: Lutz, FL.Google Scholar
Heinrichs, RW, Zakzanis, KK (1998). Neurocognitive deficit in schizophrenia: a quantitative review of the evidence. Neuropsychology 12, 426445.CrossRefGoogle Scholar
Henderson, A, Coulston, CM, Lagopoulos, J, Degabriele, R, Das, P, Malhi, G (2009). Cannabis use and cognitive functioning in schizophrenia. In Abstracts of the 9th World Congress of Biological Psychiatry, p. 126. World Federation of Societies of Biological Psychiatry: Paris.Google Scholar
Henik, A, Salo, R (2004). Schizophrenia and the Stroop effect. Behavioral and Cognitive Neuroscience Reviews 3, 4259.CrossRefGoogle ScholarPubMed
Henquet, C, Rosa, A, Krabbendam, L, Papiol, S, Fananas, L, Drukker, M, Ramaekers, JG, Van Os, J (2006). An experimental study of catechol-O-methyltransferase Val158Met moderation of Δ-9-tetrahydrocannabinol- induced effects on psychosis and cognition. Neuropsychopharmacology 31, 27482757.CrossRefGoogle ScholarPubMed
Hooker, WD, Jones, RT (1987). Increased susceptibility to memory intrusions and the Stroop interference effect during acute marijuana intoxication. Psychopharmacology 91, 2024.CrossRefGoogle ScholarPubMed
Jager, G, Kahn, RS, Van Den Brink, W, Van Ree, JM, Ramsey, NF (2006). Long-term effects of frequent cannabis use on working memory and attention: an fMRI study. Psychopharmacology 185, 358368.CrossRefGoogle ScholarPubMed
Jockers-Scherubl, MC, Wolf, T, Radzei, N, Schlattmann, P, Rentzsch, J, Gomez-Carrillo de Castro, AG, Kuhl, K (2007). Cannabis induces different cognitive changes in schizophrenic patients and healthy controls. Progress in Neuro-Psychopharmacology and Biological Psychiatry 31, 10541063.CrossRefGoogle ScholarPubMed
Joyal, C, Halle, P, Lapierre, D, Hodgins, S (2003). Drug abuse and/or dependence and better neuropsychological performance in patients with schizophrenia. Schizophrenia Research 63, 297299.CrossRefGoogle ScholarPubMed
Kanayama, G, Rogowska, J, Pope, HG, Gruber, SA, Yurgelun-Todd, D (2004). Spatial working memory in heavy cannabis users: a functional magnetic resonance imaging study. Psychopharmacology 176, 239247.CrossRefGoogle ScholarPubMed
Kumra, S, Thaden, E, DeThomas, C (2005). Correlates of substance abuse in adolescents with treatment-refractory schizophrenia and schizoaffective disorder. Schizophrenia Research 73, 369371.CrossRefGoogle ScholarPubMed
Laws, KR (1999). A meta-analytic review of Wisconsin Card Sort studies in schizophrenia: general intellectual deficit in disguise? Cognitive Neuropsychiatry 4, 130.CrossRefGoogle ScholarPubMed
Lee, J, Park, S (2005). Working memory impairments in schizophrenia: a meta-analysis. Journal of Abnormal Psychology 114, 599611.CrossRefGoogle ScholarPubMed
Li, CR (2004). Do schizophrenia patients make more perseverative than non-perseverative errors on the Wisconsin Card Sorting Test? A meta-analytic study. Psychiatry Research 129, 179190.CrossRefGoogle ScholarPubMed
Liraud, F, Verdoux, H (2002). Effect of comorbid substance use on neuropsychological performance in subjects with psychotic or mood disorders. Encephalography 28, 160168.Google ScholarPubMed
Makela, P, Wakeley, J, Gijsman, H, Robson, PJ, Bhagwagar, Z, Rogers, RD (2006). Low doses of Δ-9 tetrahydrocannabinol (THC) have divergent effects on short-term spatial memory in young, healthy adults. Neuropsychopharmacology 31, 462470.CrossRefGoogle ScholarPubMed
Mata, I, Rodriguez-Sanchez, JM, Pelayo-Teran, JM, Perez-Iglesias, R, Gonzalez-Blanch, C, Ramirez-Bonilla, M, Martinez-Garcia, O, Vazquez-Barquero, JL, Crespo-Facorro, B (2008). Cannabis abuse is associated with decision-making impairment among first-episode patients with schizophrenia-spectrum psychosis. Psychological Medicine 38, 12571266.CrossRefGoogle ScholarPubMed
McGhie, A, Chapman, J (1961). Disorders of attention and perception in early schizophrenia. British Journal of Medical Psychology 34, 103116.CrossRefGoogle ScholarPubMed
Miller, LL, Drew, WG, Kiplinger, GF (1972). Effects of marijuana on recall of narrative material and Stroop colour–word performance. Nature 237, 172173.CrossRefGoogle Scholar
Park, S (1997). Association of an oculomotor delayed response task and the Wisconsin Card Sort Test in schizophrenic patients. International Journal of Psychophysiology 27, 147151.CrossRefGoogle ScholarPubMed
Pencer, A, Addington, J (2003). Substance use and cognition in early psychosis. Journal of Psychiatry and Neuroscience 28, 4854.Google ScholarPubMed
Perry, W, Heaton, RK, Potterat, E, Roebuck, T, Minassian, A, Braff, DL (2001). Working memory in schizophrenia: transient ‘online’ storage versus executive functioning. Schizophrenia Bulletin 27, 157176.CrossRefGoogle ScholarPubMed
Pirkola, T, Tuulio-Henriksson, A, Glahn, D, Kieseppa, T, Haukka, J, Kaprio, J, Lonnqvist, J, Cannon, TD (2005). Spatial working memory function in twins with schizophrenia and bipolar disorder. Biological Psychiatry 58, 930936.CrossRefGoogle ScholarPubMed
Pope, HG, Gruber, AJ, Hudson, JI, Huestis, MA, Yurgelun-Todd, D (2001). Neuropsychological performance in longterm cannabis users. Archives of General Psychiatry 58, 909915.CrossRefGoogle Scholar
Pope, HG, Yurgelun-Todd, D (1996). The residual cognitive effects of heavy marijuana use in college students. Journal of the American Medical Association 275, 521527.CrossRefGoogle ScholarPubMed
Potvin, S, Joyal, CC, Pelletier, J, Stip, E (2008). Contradictory cognitive capacities among substance-abusing patients with schizophrenia: a meta-analysis. Schizophrenia Research 100, 242251.CrossRefGoogle ScholarPubMed
Schnell, T, Dagmar, K, Daumann, J, Gouzoulis-Mayfrank, E (2009). The role of cannabis in cognitive functioning of patients with schizophrenia. Psychopharmacology 205, 4552.CrossRefGoogle ScholarPubMed
Scholes, KE, Martin-Iverson, M (2009 a). Altered prepulse inhibition in chronic cannabis users is secondary to sustained attention deficits. Psychopharmacology. Published online: 9 October 2009. doi: 10.1007/s00213-009-1679-0.CrossRefGoogle Scholar
Scholes, KE, Martin-Iverson, MT (2009 b). Disturbed prepulse inhibition in patients with schizophrenia is consequential to dysfunction of selective attention. Psychophysiology. Published online: 12 October 2009. doi: 10.1111/j.1469-8986.2009.00927.Google ScholarPubMed
Sevy, S, Burdick, KE, Visweswaraiah, H, Abdelmessih, S, Lukin, M, Yechiam, E, Bechara, A (2007). Iowa gambling task in schizophrenia: a review and new data in patients with schizophrenia and co-occurring cannabis use disorders. Schizophrenia Research 92, 7484.CrossRefGoogle ScholarPubMed
Sheehan, DV, Lecrubier, Y, Sheehan, H, Amorim, P, Janavs, J, Weiller, E, Hergueta, T, Baker, R, Dunbar, GC (1998). The Mini-International Neuropsychiatric Interview (MINI): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. Journal of Clinical Psychiatry 59 (Suppl. 20), 2257.Google ScholarPubMed
Sheehan, DV, Lecrubier, Y, Sheehan, KH, Janavs, J, Weiller, E, Keskiner, A, Schinka, J, Knapp, E, Sheehan, MF, Dunbar, GC (1997). The validity of the Mini International Neuropsychiatric Interview (MINI) according to the SCID-P and its reliability. European Psychiatry 12, 232241.CrossRefGoogle Scholar
Silver, H, Feldman, P, Bilker, W, Gur, RC (2003). Working memory deficit as a core neuropsychological dysfunction in schizophrenia. American Journal of Psychiatry 160, 18091816.CrossRefGoogle Scholar
Sitskoorn, MM, Aleman, A, Ebisch, SJH, Appels, MCM, Kahn, RS (2004). Cognitive deficits in relatives of patients with schizophrenia: a meta-analysis. Schizophrenia Research 71, 285295.CrossRefGoogle ScholarPubMed
Smith, RC, Warner-Cohen, J, Matute, M, Butler, E, Kelly, E, Vaidhyanathaswamy, S, Khan, A (2006). Effects of nicotine nasal spray on cognitive function in schizophrenia. Neuropsychopharmacology 31, 637643.CrossRefGoogle Scholar
Solowij, N, Michie, PT (2007). Cannabis and cognitive dysfunction: parallels with endophenotypes of schizophrenia. Journal of Psychiatry and Neuroscience 32, 3052.Google ScholarPubMed
Solowij, N, Stephens, RS, Roffman, RA, Babor, T, Kadden, R, Miller, M, Christiansen, K, McRee, B, Vendetti, J (2002). Cognitive functioning of long-term heavy cannabis users seeking treatment. JAMA: Journal of the American Medical Association 287, 11231131.CrossRefGoogle ScholarPubMed
Stirling, J, Lewis, S, Hopkins, R, White, C (2005). Cannabis use prior to first onset psychosis predicts spared neurocognition at 10-year follow-up. Schizophrenia Research 75, 135137.CrossRefGoogle ScholarPubMed
Tan, H, Sust, S, Buckholtz, JW, Mattay, VS, Meyer-Lindenberg, A, Egan, MF, Weinberger, DR, Callicott, JH (2006). Dysfunctional prefrontal regional specialization and compensation in schizophrenia. American Journal of Psychiatry 163, 19691977.CrossRefGoogle Scholar
Thoma, P, Wiebel, B, Daum, I (2007). Response inhibition and cognitive flexibility in schizophrenia with and without comorbid substance use disorder. Schizophrenia Research 92, 168180.CrossRefGoogle ScholarPubMed
Troisi, A, Pasini, A, Saracco, M, Spalletta, G (1998). Psychiatric symptoms in male cannabis users not using other illicit drugs. Addiction 93, 487492.CrossRefGoogle Scholar
Twamley, EW, Palmer, BW, Jeste, DV, Taylor, MJ, Heaton, RK (2006). Transient and executive function working memory in schizophrenia. Schizophrenia Research 87, 185190.CrossRefGoogle Scholar
Wadsworth, EJK, Moss, SC, Simpson, SA, Smith, AP (2006). Cannabis use, cognitive performance and mood in a sample of workers. Journal of Psychopharmacology 20, 1423.CrossRefGoogle Scholar
Waters, AJ, Sutton, SR (2000). Direct and indirect effects of nicotine/smoking on cognition in humans. Addictive Behaviors 25, 2943.CrossRefGoogle ScholarPubMed
Wechsler, D (1997). WMS-III Administration and Scoring. The Psychological Corporation: San Antonio, TX.Google Scholar
Wobrock, T, Ecker, UK, Scherk, H, Schneider-Axmann, T, Falkai, P, Gruber, O (2008). Cognitive impairment of executive function as a core symptom of schizophrenia. World Journal of Biological Psychiatry 29, 112.Google Scholar
Wobrock, T, Sittinger, H, Behrendt, B, D'Amelio, R, Falkai, P, Caspari, D (2007). Comorbid substance abuse and neurocognitive function in recent-onset schizophrenia. European Archives of Psychiatry and Clinical Neuroscience 257, 203210.CrossRefGoogle ScholarPubMed
Wood, SW (2003). Chlorpromazine equivalent doses for the newer atypical antipsychotics. Journal of Clinical Psychiatry 64, 663667.CrossRefGoogle Scholar
Yucel, M, Bora, E, Lubman, D, Brewer, WJ, Cotton, S, Conus, P, Condello, A, Wood, S, McGorry, P, Pantelis, C (2009). Effects of cannabis use on cognitive deficits in first-episode psychosis. In Abstracts of the 9th World Congress of Biological Psychiatry, p. 126. World Federation of Societies of Biological Psychiatry: Paris.Google Scholar
29
Cited by

Save article to Kindle

To save this article to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Cannabis use and neuropsychological performance in healthy individuals and patients with schizophrenia
Available formats
×

Save article to Dropbox

To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.

Cannabis use and neuropsychological performance in healthy individuals and patients with schizophrenia
Available formats
×

Save article to Google Drive

To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.

Cannabis use and neuropsychological performance in healthy individuals and patients with schizophrenia
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *