Exploring the relationship between recency and frequency of cannabis use and diminished expression and apathy as two dimensions of negative symptoms in first episode psychosis. A one-year follow-up study.
H. M. Ihler, T. Lagerberg, S. H. Lyngstad, Ingrid S. Melle, K. L. Romm
Schizophrenia Research August 25, 2021 DOI: 10.1016/j.schres.2021.08.004 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 460 |
| Population | People with first-episode psychosis |
| Duration | Baseline assessment with 12-month follow-up |
| Topics | Cannabis |
| Key findings | Frequency of cannabis use two years before baseline was associated with baseline severity of diminished expression and apathy, but only the diminished expression association held after adjusting for clinical and demographic confounders. Baseline cannabis use frequency also had a significant effect on the development of diminished expression over 12 months. The authors suggest a dose-response relationship between use frequency and symptom severity. |
Abstract
The association between cannabis use and negative symptoms remains unclear because of inconsistent results in existing studies. In this study we aimed to investigate the association between different aspects of cannabis use and 1) diminished expression and 2) apathy as a two-dimensional model of negative symptoms in a sample of 460 participants with first-episode psychosis. Data were collected on relevant clinical and demographic factors including diagnostics and habits of drug use at baseline, with a follow-up assessment after 12-months. We found an association between the frequency of cannabis use two years prior to baseline and the severity of diminished expression and apathy at baseline, while only the association to diminished expression held after controlling for potential clinical and demographic confounders. Frequency of cannabis use at baseline also had a significant effect on the development of diminished expression over the 12-month follow-up period. In conclusion, this study suggests that the frequency of cannabis use contributes to the severity of diminished expression at baseline, and to the progression of diminished expression after 12-months follow-up. Our findings also imply a dose-response relationship between frequency of use and severity of symptoms and add evidence to an association between cannabis use and negative symptoms.
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
Cited by 4
- Association between cannabis use and symptom dimensions in schizophrenia spectrum disorders: an individual participant data meta-analysis on 3053 individuals EClinicalMedicine September 8, 2023
- The trajectory of two negative symptom dimensions in first-episode psychosis and the role of cannabis use: A 10-year follow-up study. Schizophrenia Research January 25, 2023
- Role of cyclin-dependent kinase 5 in psychosis and the modulatory effects of cannabinoids. Neurobiology of Disease 2023
- Cannabis induced psychosis: A comparative study between cannabis use disorder and cocaine use disorder
Cites 6
- Psychiatric effects of cannabis The British Journal of Psychiatry February 1, 2001
- Daily use of high-potency cannabis is associated with more positive symptoms in first-episode psychosis patients: the EU-GEI case–control study Psychological Medicine March 18, 2020
- Premorbid Adjustment and IQ in Patients With First-Episode Psychosis: A Multisite Case-Control Study of Their Relationship With Cannabis Use Schizophrenia Bulletin July 2, 2019
- Continued versus discontinued cannabis use in patients with psychosis: a systematic review and meta-analysis. The Lancet Psychiatry March 1, 2016
- Anandamide levels in cerebrospinal fluid of first-episode schizophrenic patients: impact of cannabis use. Schizophrenia Research August 2007
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