People With Psychosis Had Stronger Negative Feelings About Cannabis but Used It Anyway
Schizophrenia patients and healthy controls had similar implicit (automatic) negative associations toward cannabis, but patients had stronger explicit negative expectations yet continued using, suggesting relaxation expectancies drive use despite knowing the risks.
Quick Facts
What This Study Found
Seventy patients with recent-onset psychotic disorder and 61 healthy controls with varying cannabis use levels were tested on both implicit (automatic) and explicit (conscious) associations toward cannabis.
Surprisingly, there were no differences in implicit associations between patients and controls. Both groups showed strong negative implicit associations toward cannabis.
However, patients scored significantly higher on explicit negative affect expectancies, meaning they were more consciously aware of negative consequences of cannabis use.
Despite this, explicit relaxation expectancies were the strongest predictors of actual cannabis use and craving in both groups. The expectation that cannabis would help them relax appeared to override their negative associations.
The finding that users had strong negative implicit associations suggested they were engaging in a behavior they did not implicitly "like."
Key Numbers
70 psychotic disorder patients, 61 healthy controls. Both groups showed strong negative implicit cannabis associations. Patients had stronger explicit negative expectations. Explicit relaxation expectancies were the strongest predictor of use and craving.
How They Did This
Cross-sectional study using three Single-Category Implicit Association Tests (relaxed, active, negative) and an explicit expectancy questionnaire in 70 patients with recent-onset psychotic disorder and 61 healthy controls with varying cannabis use levels.
Why This Research Matters
Understanding why schizophrenia patients continue using cannabis despite knowing it worsens their illness could improve treatment approaches. The dominance of relaxation expectancies suggests targeting these specific beliefs in therapy.
The Bigger Picture
This study challenges the assumption that cannabis users with psychosis lack insight into the harm. They know cannabis is harmful (strong explicit negative associations) but use it anyway because the expectation of relaxation overrides their awareness of risk.
What This Study Doesn't Tell Us
Cross-sectional design. Implicit measures may not capture all aspects of automatic processing. The study cannot determine whether relaxation expectancies drive use or are post-hoc justifications. Different levels of cannabis use between groups may confound comparisons.
Questions This Raises
- ?Would therapeutic interventions targeting relaxation expectancies reduce cannabis use in psychosis?
- ?Can alternative relaxation strategies replace the cannabis use motivation?
- ?Do implicit associations change with treatment?
Trust & Context
- Key Stat:
- Relaxation expectancies predicted cannabis use more than negative awareness in both groups
- Evidence Grade:
- Cross-sectional study using validated implicit and explicit measures. Moderate sample sizes. Cannot establish causal direction between expectancies and use.
- Study Age:
- Published in 2010. Expectancy-based approaches to understanding cannabis use in psychosis have continued to develop.
- Original Title:
- Implicit and explicit affective associations towards cannabis use in patients with recent-onset schizophrenia and healthy controls.
- Published In:
- Psychological medicine, 40(8), 1325-36 (2010)
- Authors:
- Dekker, N, Smeerdijk, A M, Wiers, R W(4), Duits, J H, van Gelder, G, Houben, K, Schippers, G, Linszen, D H, de Haan, L
- Database ID:
- RTHC-00407
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Why do people with psychosis use cannabis if they know it is harmful?
This study found that the expectation of relaxation from cannabis was a stronger motivator than awareness of harm. People may use cannabis for immediate relief of tension or distress despite knowing about longer-term negative consequences.
What are implicit associations?
Implicit associations are automatic, often unconscious reactions that can be measured with reaction-time tests. They may differ from what people consciously report. In this study, both users and non-users showed implicit negative associations toward cannabis, suggesting the behavior conflicts with automatic attitudes.
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Cite This Study
https://rethinkthc.com/research/RTHC-00407APA
Dekker, N; Smeerdijk, A M; Wiers, R W; Duits, J H; van Gelder, G; Houben, K; Schippers, G; Linszen, D H; de Haan, L. (2010). Implicit and explicit affective associations towards cannabis use in patients with recent-onset schizophrenia and healthy controls.. Psychological medicine, 40(8), 1325-36. https://doi.org/10.1017/S0033291709991814
MLA
Dekker, N, et al. "Implicit and explicit affective associations towards cannabis use in patients with recent-onset schizophrenia and healthy controls.." Psychological medicine, 2010. https://doi.org/10.1017/S0033291709991814
RethinkTHC
RethinkTHC Research Database. "Implicit and explicit affective associations towards cannabi..." RTHC-00407. Retrieved from https://rethinkthc.com/research/dekker-2010-implicit-and-explicit-affective
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.