Are reasons for first using cannabis associated with subsequent cannabis consumption (standard THC units) and psychopathology?

Edoardo Spinazzola; Hannah Degen; Isabelle Austin-Zimmerman; Giulia Trotta; Edward Chesney; Zhikun Li; Luis Alameda; Bok Man Leung; Yifei Lang; Andrea Quattrone; Diego Quattrone; Erika Castrignanò; Kim Wolff; Robin Murray; Tom P. Freeman; Marta Di Forti

doi:10.1136/bmjment-2025-301810

Are reasons for first using cannabis associated with subsequent cannabis consumption (standard THC units) and psychopathology?

Edoardo Spinazzola, Hannah Degen, Isabelle Austin-Zimmerman, Giulia Trotta, Edward Chesney, Zhikun Li, Luis Alameda, Bok Man Leung, Yifei Lang, Andrea Quattrone, Diego Quattrone, Erika Castrignanò, Kim Wolff, Robin Murray, Tom P. Freeman, Marta Di Forti

Research output: Contribution to journal › Article › peer-review

Abstract

Background: Reasons for first using cannabis (RFUC) may influence later use patterns and mental health outcomes. However, limited research has explored self-medication versus social RFUCs in depth, and their associations with cannabis use patterns and psychopathology in the general population.

Objectives: We examined RFUCs and their associations with (1) reasons for continuing cannabis use, (2) weekly THC (delta-9-tetrahydrocannabinol) unit consumption and (3) symptoms of paranoia, anxiety and depressive symptoms.

Methods: We analysed data from the Cannabis&Me (CAMe) population survey (March 2022–July 2024), including 2573 (75.9%) current and 816 (24.1%) past cannabis users aged 18 years or older.

Findings: Participants reported a mean weekly consumption of 206 THC units (SD=268). Initiating cannabis use for anxiety (β=36.22, p=3.3e−03), depression (β=40.37, p=1.74e−03) or because ‘family members were using it’ (β=87.43, p=1.22e−09) was associated with higher weekly THC units. RFUC to relieve physical discomfort (β=8.89, p=4.12e−07), pain (β=7.24, p=5.56e−06), anxiety (β=9.67, p=1.63e−16), depression (β=9.12, p=1.21e−13) and minor psychotic symptoms (β=16.46, p=1.2e−04) were linked to higher paranoia scores. Similar associations were observed for anxiety and depression. Conversely, starting for fun (β=−3.71, p=3.49e−05) or curiosity (β=−2.61, p=5e−03) was associated with lower paranoia and anxiety. RFUC for ‘boredom’ was linked to increased depression (β=1.09, p=3.8e−03).

Conclusions: Initiating cannabis use for self-medication is associated with higher average THC consumption, and increased anxiety, depression and paranoia.

Clinical implications: Asking individuals why they first used cannabis may serve as a cost-effective screening tool to identify those who could benefit from monitoring, support, or referral to intervention services.

Original language	English
Pages (from-to)	1-8
Number of pages	8
Journal	BMJ Mental Health
Volume	28
Issue number	1
Early online date	26 Aug 2025
DOIs	https://doi.org/10.1136/bmjment-2025-301810
Publication status	Published - 26 Aug 2025

Data Availability Statement

Data are available upon reasonable request. Data are available from the corresponding author upon reasonable request under the
condition of approval of the Cannabis&Me steering committee

Funding

The Cannabis&Me project was founded by the UKRI MRC (IRAS project ID 301405). MDF, IA-Z, GT and ES were supported by the MRC SRF Fellowship (MRC MR/T007818/1). ES was also supported by Lord Leverhulme’s Charitable Trust and the Velvet Foundation. LA thanked the Adrian and Simone Frutiger Fellowship and the Carigest SA Foundation for their support. TPF is funded by a UKRI Future Leaders Fellowship (MR/Y017560/1). The funders were not involved in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.

Funders	Funder number
Medical Research Council

Keywords

Adult psychiatry
Cross-Sectional Studies
Marijuana Abuse
Substance misuse
ubstance-Related Disorders

ASJC Scopus subject areas

Psychiatry and Mental health

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1136/bmjment-2025-301810Licence: CC BY

https://mentalhealth.bmj.com/content/28/1/e301810Licence: CC BY

Cite this

Spinazzola, E., Degen, H., Austin-Zimmerman, I., Trotta, G., Chesney, E., Li, Z., Alameda, L., Leung, B. M., Lang, Y., Quattrone, A., Quattrone, D., Castrignanò, E., Wolff, K., Murray, R., Freeman, T. P., & Forti, M. D. (2025). Are reasons for first using cannabis associated with subsequent cannabis consumption (standard THC units) and psychopathology? BMJ Mental Health, 28(1), 1-8. https://doi.org/10.1136/bmjment-2025-301810

Spinazzola, E, Degen, H, Austin-Zimmerman, I, Trotta, G, Chesney, E, Li, Z, Alameda, L, Leung, BM, Lang, Y, Quattrone, A, Quattrone, D, Castrignanò, E, Wolff, K, Murray, R, Freeman, TP & Forti, MD 2025, 'Are reasons for first using cannabis associated with subsequent cannabis consumption (standard THC units) and psychopathology?', BMJ Mental Health, vol. 28, no. 1, pp. 1-8. https://doi.org/10.1136/bmjment-2025-301810

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title = "Are reasons for first using cannabis associated with subsequent cannabis consumption (standard THC units) and psychopathology?",

abstract = "Background: Reasons for first using cannabis (RFUC) may influence later use patterns and mental health outcomes. However, limited research has explored self-medication versus social RFUCs in depth, and their associations with cannabis use patterns and psychopathology in the general population. Objectives: We examined RFUCs and their associations with (1) reasons for continuing cannabis use, (2) weekly THC (delta-9-tetrahydrocannabinol) unit consumption and (3) symptoms of paranoia, anxiety and depressive symptoms. Methods: We analysed data from the Cannabis\&Me (CAMe) population survey (March 2022–July 2024), including 2573 (75.9\%) current and 816 (24.1\%) past cannabis users aged 18 years or older. Findings: Participants reported a mean weekly consumption of 206 THC units (SD=268). Initiating cannabis use for anxiety (β=36.22, p=3.3e−03), depression (β=40.37, p=1.74e−03) or because {\textquoteleft}family members were using it{\textquoteright} (β=87.43, p=1.22e−09) was associated with higher weekly THC units. RFUC to relieve physical discomfort (β=8.89, p=4.12e−07), pain (β=7.24, p=5.56e−06), anxiety (β=9.67, p=1.63e−16), depression (β=9.12, p=1.21e−13) and minor psychotic symptoms (β=16.46, p=1.2e−04) were linked to higher paranoia scores. Similar associations were observed for anxiety and depression. Conversely, starting for fun (β=−3.71, p=3.49e−05) or curiosity (β=−2.61, p=5e−03) was associated with lower paranoia and anxiety. RFUC for {\textquoteleft}boredom{\textquoteright} was linked to increased depression (β=1.09, p=3.8e−03). Conclusions: Initiating cannabis use for self-medication is associated with higher average THC consumption, and increased anxiety, depression and paranoia. Clinical implications: Asking individuals why they first used cannabis may serve as a cost-effective screening tool to identify those who could benefit from monitoring, support, or referral to intervention services.",

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