The association between early cannabis use and psychotic-like experiences in a community adolescent sample

“These findings are consistent with accumulating evidence suggesting that cannabis exposure is associated with the development of both clinical and non-clinical psychotic symptoms (Arseneault et al., 2002; Henquet et al., 2005a; Moore et al., 2007; van Os et al., 2002).”

“…polymorphism of the COMT gene has also been associated with the increased risk of developing adult schizophreniform disorder following cannabis exposure during adolescence (Caspi et al., 2005), although this association was only found among individuals who had used cannabis before the age of 18.”

“While one study has reported that early onset cannabis use (before age 16) is associated with increased risk of developing psychosis, another has suggested this appears to be the result of cumulative exposure (Arseneault et al., 2002; Zammit et al., 2002).”

“…among young people experiencing PLEs and at ultra high risk of psychosis (UHR; presence of attenuated psychotic symptoms and/or family history) (Cannon et al., 2008; Kristensen and Cadenhead, 2007; Yung et al., 2003, 2004), although two studies have failed to find specific effects for cannabis…”

“…high risk of psychosis (UHR; presence of attenuated psychotic symptoms and/or family history) (Cannon et al., 2008; Kristensen and Cadenhead, 2007; Yung et al., 2003, 2004), although two studies have failed to find specific effects for cannabis abuse/dependence (Cannon et al., 2008; Phillips et…”

“The YRBS was used to provide measures of the age of onset of cannabis, tobacco and alcohol use and the frequency of tobacco, alcohol, illicit (heroin, methamphetamine, ecstasy, hallucinogen, cocaine) and injecting drug use in the past year.”

“The positive symptoms scale of the Community Assessment of Psychic Experiences (CAPE) was used to measure the frequency (1 = never to 4 = nearly always) of PLEs (Stefanis et al., 2002).”

“These findings are consistent with accumulating evidence suggesting that cannabis exposure is associated with the development of both clinical and non-clinical psychotic symptoms (Arseneault et al., 2002; Henquet et al., 2005a; Moore et al., 2007; van Os et al., 2002).”

“Evidence for a robust association between cannabis use and the development of psychosis has emerged from a series of recent meta-analytic reviews (Arseneault et al., 2004; Henquet et al., 2005b;Moore et al., 2007; Semple et al., 2005).”

“While one study has reported that early onset cannabis use (before age 16) is associated with increased risk of developing psychosis, another has suggested this appears to be the result of cumulative exposure (Arseneault et al., 2002; Zammit et al., 2002).”

“These findings are consistent with accumulating evidence suggesting that cannabis exposure is associated with the development of both clinical and non-clinical psychotic symptoms (Arseneault et al., 2002; Henquet et al., 2005a; Moore et al., 2007; van Os et al., 2002).”

“…high risk of psychosis (UHR; presence of attenuated psychotic symptoms and/or family history) (Cannon et al., 2008; Kristensen and Cadenhead, 2007; Yung et al., 2003, 2004), although two studies have failed to find specific effects for cannabis abuse/dependence (Cannon et al., 2008; Phillips et…”

“These findings are consistent with accumulating evidence suggesting that cannabis exposure is associated with the development of both clinical and non-clinical psychotic symptoms (Arseneault et al., 2002; Henquet et al., 2005a; Moore et al., 2007; van Os et al., 2002).”

“Evidence for a robust association between cannabis use and the development of psychosis has emerged from a series of recent meta-analytic reviews (Arseneault et al., 2004; Henquet et al., 2005b;Moore et al., 2007; Semple et al., 2005).”

“‘Have you ever felt as if there is a conspiracy against you?’) (Yung et al., 2009).”

“…previous research findings in community samples of adolescents and young adults (aged 19+), in which the frequency of both lifetime and pastmonth cannabis use significantlywas associated with the positive PLE score on the CAPE (Miettunen et al., 2008; Stefanis et al., 2004; Verdoux et al., 2003).”

“In addition, a 20 year prospective study found that cannabis use in adolescence was the strongest predictor of continuously high scores on schizophrenia nuclear symptoms in a community study of 591 young adults (aged 20–21) (Rossler et al., 2007).”

“…that functional polymorphism of the catechol-o-methyltransferase (COMT Val158Met) gene may moderate the effects of cannabis use on psychotic symptoms among individuals with high psychometric psychosis liability (defined as high scorers on the CAPE positive PLE scale) (Henquet et al., 2006).”

“The current study also relied on self-report measures of both PLE and substance use, although adolescent drug users have been found to provide reliable self reports of drug and alcohol use in previous studies (Buchan et al., 2002).”

“…previous research findings in community samples of adolescents and young adults (aged 19+), in which the frequency of both lifetime and pastmonth cannabis use significantlywas associated with the positive PLE score on the CAPE (Miettunen et al., 2008; Stefanis et al., 2004; Verdoux et al., 2003).”

“…experiencing PLEs and at ultra high risk of psychosis (UHR; presence of attenuated psychotic symptoms and/or family history) (Cannon et al., 2008; Kristensen and Cadenhead, 2007; Yung et al., 2003, 2004), although two studies have failed to find specific effects for cannabis abuse/dependence…”

“…of psychosis (UHR; presence of attenuated psychotic symptoms and/or family history) (Cannon et al., 2008; Kristensen and Cadenhead, 2007; Yung et al., 2003, 2004), although two studies have failed to find specific effects for cannabis abuse/dependence (Cannon et al., 2008; Phillips et al., 2002).”

“There is also evidence that early onset cannabis use (below age 16) and the frequency of cannabis use (lifetime and past month) are associated with positive subthreshold psychotic symptoms, or PLEs in adolescents and young adults (Miettunen et al., 2008; Stefanis et al., 2004; Verdoux et al., 2003).”

“Conversely, it is possible that this associationwas due to the influence of PLE's on cannabis use, in a manner consistent with the self medication hypothesis (Verdoux et al., 2005).”

“However, the first comprehensive scientific paper openly discussing the idea that the endocannabinoid system might play a role in the neurobiology of depression is fairly recent, dating back only to 2005 (Hill and Gorzalka, 2005a).”

“In the general population, cannabis use is dosedependently associated with subclinical psychiatric symptoms such as psychotic experiences and negative symptoms (Arseneault et al. 2002 ; Fergusson et al. 2003 ; Verdoux et al. 2003 ; Stefanis et al. 2004 ; Konings et al. 2008 ; Miettunen et al. 2008 ; Hides et al. 2009).”

“…bullying (Kelleher et al., 2008; Kelleher, Keeley et al., 2013), suicidal behavior (ideation, attempts) (Kelleher et al., 2014; Kelleher, Corcoran et al., 2013), cannabis use (Hides et al., 2009), and increased risk for multiple co-occurring Axis I mental disorders (Kelleher, Keeley et al., 2012).”

“(2015), http://dx.doi.org interesting given the emphasis on this link in previous studies (Henquet et al., 2005; Hides et al., 2009; Mackie et al., 2011; Scott et al., 2009).”

“Several studies have subsequently partially replicated this result (42, 43), while others have failed to replicate it (44).”

“In particular, population-based studies in adolescents have reported that early onset cannabis use is associated with a greater likelihood of DLE endorsement [11,16,17].”

“…research, the persistence of PLEs is influenced by several environmental factors such as childhood trauma (Arseneault et al., 2011), cannabis use (Hides et al., 2009), urban environment (Spauwen et al., 2006), and student status (McGrath et al., 2015), as well as personal factors, such as coping…”

“An Australian study by Hides et al. found that the frequency of cannabis use in the past year was associated with the CAPE s positive symptom scale total score in a community sample of 880 adolescents in Melbourne (15).”

“Studies have repeated this finding in a variety of populations (Zammit et al. 2002; Lynskey et al. 2003; Stefanis et al. 2004; Konings et al. 2008; Hides et al. 2009; Shapiro & Buckley-Hunter, 2010; Skinner et al. 2011).”

“The total score on the ISDI was then entered into two separate linear regressions controlling for age, gender, depressive symptoms, and recent drug use, known confounds to the link between sleep dysfunction and PLEs (Kaneita et al., 2006; Schierenbeck et al., 2008; Hides et al., 2009).”

“…2012; Friedman, Utada, Glickman, & Morrissey, 1987; Garland & Howard, 2010; Goulter, McMahon, & Dodge, 2019; Harley et al., 2010; Hartsell, 2021; Hides et al., 2009; Jones, Calkins, Scott, Bach, & Gur, 2017; Jones, Gage, & Heron, 2018; Konings, Henquet, Maharajh, Hutchinson, & Van Os, 2008;…”

“Studies amongst adolescent sub-clinical populations have also linked cannabis use with increasing risks for PEs (Fergusson et al., 2003; Henquet et al., 2005a, 2005b; Hides et al., 2009; Van Gastel et al., 2012) (r1⁄40.”

“Findings from prior literature were used to determine heavy binge drinking (Hasin and Beseler, 2009; Schulenberg et al., 1996) and marijuana use (Harper et al., 2012; Hides et al., 2009; Schulenberg et al., 2005) thresholds.”

“It is not clear whether cannabis use is associated with some specific dimension of psychosis, as studies looking into such specific associations have been contradictory (Skosnik et al., 2001; Johns et al., 2004; Stefanis et al., 2004; Hides et al., 2009; Henquet et al., 2010).”

“PLE are associated with the development of schizophrenia spectrum disorders as well as a number of other mental health problems such as anxiety, depression, substance abuse, self-harm and suicide risk (van Os et al., 2002; Hides et al., 2009; Saha et al., 2011a,b).”

“Several factors have been shown to be associated with PE (Spauwen et al., 2006; Campbell andMorrison, 2007; Hides et al., 2009).”

“…sleep disturbances (Lee et al., 2012), childhood trauma and bullying (Kelleher et al., 2008, 2013b), suicidal behaviour (ideation, attempts) (Kelleher et al., 2014), cannabis used (Hides et al., 2009), and increase risk for multiple co‐occurring Axis I mental disorders (Kelleher et al., 2012b).”

“…are important potential moderators of the impacts of CB use (Anglin et al., 2012; Crean et al., 2011; Fontes et al., 2011; Gruber et al., 2012; Hides et al., 2009; Stefanis et al., 2004, 2013; Weinstein et al., 2016; Wilson et al., 2000), it was hypothesized that differences in rsFC would…”

“Contrastingly, Hides ([42]; data not included in analysis due to a very low case number) found the highest psychotic effects at an intermediate dose, and Di Forti et al. ([30]; data included from 2019 publication) found increasing OR with earlier drug intake, high THC content, and frequent cannabis…”

“…Binbay et al. 2012; Di Forti et al., 2009; D’Souza et al., 2020; Fergusson et al., 2003, 2005; Fonseca-Pedrero et al., 2020; Henquet et al., 2005; Hides et al., 2009; Karcher et al., 2019; Leadbeater et al., 2019; Mackie et al., 2013; Manrique-Garcia et al., 2012; McHugh et al., 2017; Miettunen…”

“It has been hypothesized that the relationship could be based on recency of use (e.g., Hides et al., 2009), dose‐response (e.g., Ruiz‐Veguilla et al., d. nal/h 2013), or against a backdrop of other psychosis risk factors such as childhood trauma (e.g., Alemany et al., 2014).”

“experience in adolescent general populations (Hides et al., 2009; Scott et al., 2009), in particular, visual hallucinations (Caton et al.”

“In community samples of adolescents and young adults, different levels of cannabis exposure (lifetime, recent, regular) are differentially associated with positive subthreshold psychotic symptoms [36].”

“, 2007), and a number of studies have shown a link between cannabis and psychotic-like experiences in the general population (Hides et al., 2009; Nunn, Rizza, & Peters, 2001).”

“4), researchers found that early onset of cannabis use was associated with a greater risk of developing psychotic-like experiences (PLEs) and psychosis [66].”

“Level of lifetime consumption was also related to hallucinatory experiences, in line with previous research (Hides et al., 2009).”

“Rey-Osterrieth complex figure test: The Rey-Osterrieth Complex Figure Test (ROCF a neuropsychological assessment in) is which examinees are asked to reproduce a complicated line drawing, first by copying it freehand (recognition), and then drawing from memory (recall) [11-14].”

“…r.com/ locate /schres Letter to the Editors Comment on Hides et al. — Cannabis use and psychotic-like experiences Dear Editors, The research paper by Hides et al. (2009) in July's issue of Schizophrenia Research examined the relationship between cannabis use and psychotic-like experiences (PLEs)…”