Is there a common vulnerability in cannabis phenomenology and schizotypy? The role of the N170 ERP.
Gabriel A Brooks, Colleen A Brenner
Schizophrenia Research July 2018 DOI: 10.1016/j.schres.2017.11.019 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study Peer reviewed |
|---|---|
| Sample size | 97 |
| Population | 97 individuals grouped by Cannabis Experiences Questionnaire and Schizotypal Personality Questionnaire scores into High CEQ, High SPQ, High on Both, Average Users, and non-using Controls |
| Measures | N170 event-related potential (ERP), Cannabis Experiences Questionnaire (CEQ), Schizotypal Personality Questionnaire (SPQ) |
| Topics | Cannabis Philosophy of mind |
| Keywords | Cognition Event-related potential N170 Schizotypal personality Schizotypy |
| Key findings | The high-scoring experimental groups (High CEQ, High SPQ, High on Both) showed significantly reduced N170 event-related potentials compared to non-using Controls during a visual face perception task. The Average User group did not significantly differ from Controls and approached significance with the High SPQ group. The high-scoring groups did not differ significantly from each other. The authors suggest the attenuated N170 may reflect a manifestation of an underlying shared vulnerability. |
Abstract
Cannabis use is a known risk factor for the development of psychosis, although the precise nature of this relationship is unclear. The phenomenological experiences associated with cannabis use vary dramatically, and for some resemble certain features of psychosis. We hypothesized that individuals who report particularly unusual experiences associated with cannabis use would demonstrate similar electrophysiological patterns to those who score high on schizotypal personality traits. The Cannabis Experiences Questionnaire (CEQ) and the Schizotypal Personality Questionnaire (SPQ) were used to measure these experiences and traits. A sample of 97 individuals were placed into one of three experimental or two control groups based on their questionnaire scores. These were the "High CEQ", "High SPQ", "High on Both", "Average Users" and "Control" (non-using) groups. Participants completed a visual face perception task. Electroencephalography was used to measure the neural response to the stimuli. The N170 event-related potential (ERP) was used to measure perceptual encoding of the stimulus. The experimental groups elicited significantly reduced N170 ERPs compared to the Control group. The Average User group did not significantly differ from the Control group, and approached significance with the High SPQ group. None of the high scoring groups significantly differed in N170 ERP response from each other. Replicating past research, the CEQ and SPQ scales moderately correlated with each other. The attenuated N170 ERP demonstrated by the high scoring experimental groups may reflect a manifestation of an underlying shared vulnerability.
Comparable studies
Other observational and cohort studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| High-potency cannabis and the risk of psychosis People with first episode of psychosis and healthy controls from the local population | 2009 | Case-control study | n = 454 |
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Impaired cognitive performance in drug free users of recreational ecstasy (MDMA) Otherwise healthy young people | 2000 | Observational | |
| Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study Individuals from the general population in Germany aged 14-24 at baseline | 2011 | Observational cohort | n = 1,923 |
| Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases Patients treated for cannabis-induced psychotic symptoms in Denmark between 1994 and... | 2005 | Observational cohort | n = 535 |
Citations in the library
Cites 7
- Cannabis use and psychotic disorders: an update Drug and Alcohol Review November 30, 2004
- Cannabis, Psychosis, and Mortality: A Cohort Study of 50,373 Swedish Men. American Journal of Psychiatry August 1, 2016
- Acute cannabis use causes increased psychotomimetic experiences in individuals prone to psychosis Psychological Medicine June 1, 2009
- Schizotypy and psychosis-like experiences from recreational cannabis in a non-clinical sample Psychological Medicine September 1, 2008
- Psychophysiological evidence of altered neural synchronization in cannabis use: relationship to schizotypy. American Journal of Psychiatry October 2006
and 2 more in the library