TOPLINE:

A network analysis comparing mental health symptoms between alcohol users and alcohol-cannabis co-users revealed both shared and distinct patterns of symptom associations. Co-users showed stronger connections between somatic symptoms and mental health outcomes; age had no moderating effect on these relationships.

METHODOLOGY:

• Researchers conducted a cross-sectional observational study of 740 participants aged 16-81 years, including 446 alcohol users (57.6% females) and 294 alcohol and cannabis co-users (50.7% females), across multiple countries.
• The study used the network analysis to model interactions between 12 mental health symptom domains and six substance use characteristics.
• The study analysed the self-reported severity of mental health symptoms using the Diagnostic and Statistical Manual of Mental Disorders (DSM) Level 1 Cross-Cutting Symptom Measure.
• The quantity and frequency of use and problematic use of cannabis and alcohol were measured using Cannabis Use Disorders Identification Test-Revised and Alcohol Use Disorders Identification Test scores, respectively.
• The researchers incorporated age as a continuous moderator to determine whether associations between substance use and mental health varied across the lifespan.

TAKEAWAY:

• The substance co-user group demonstrated higher quantity/frequency of use, problematic use, and severity across all assessed mental health symptoms than the alcohol-only group (P ≤ .001 for all).
• Somatic symptoms were significantly more central in the co-use network (strength, 1.31) than in the alcohol-only use network (strength, 0.17; P = .018).
• Alcohol-related problems were uniquely linked to anxiety, personality functioning, and suicidal ideation (partial correlation coefficients, 0.03, 0.01, and 0.01, respectively), and cannabis-related problems were linked to mania and dissociation (partial correlation coefficients, 0.05 and 0.02, respectively).
• Age did not moderate associations between substance use and mental health symptoms, suggesting that these relationship patterns might remain stable throughout life.

IN PRACTICE:

"Strong associations between symptoms of anxiety, personality functioning and depression were present in two different samples of substance users, supporting the transdiagnostic perspective," the authors wrote.

"These mental health symptoms may have pivotal roles in the psychopathological profile of substance users in general and represent key targets for therapeutic interventions aimed at reducing overall symptom manifestation," they added.

SOURCE:

This study was led by Inês Macedo, University of Porto, Porto, Portugal. It was published online on January 19, 2026, in Addiction.

LIMITATIONS:

This study was limited by the use of DSM level 1 subscale sum scores rather than individual items. The sample had predominantly low-risk alcohol users, and the participant pool was skewed towards those aged 30 years or younger, limiting generalisability. The cross-sectional design precluded causal inferences. The lack of a cannabis-only comparison group and the inclusion of individuals with a past history of cannabis use in the alcohol-only group hindered the ability to isolate substance-specific effects.

DISCLOSURES:

This study was supported by a grant from Fundação para a Ciência e Tecnologia awarded to one author. Additional support was provided through a grant from the Dutch Research Council and the Dutch Ministry of Education, Culture and Science. The authors reported having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.