Alcohol problems link uniquely to anxiety, personality issues, and suicidal thoughts, while cannabis problems link to mania and dissociation — and these patterns remain stable across the lifespan.
Dual-diagnosis clinicians, addiction psychiatrists, mental health screeners
What the researchers found
Alcohol-cannabis co-users had higher severity on all mental health symptoms vs. alcohol-only users, yet network structures were similar. Key distinction: alcohol problems uniquely linked to anxiety, personality functioning, and suicidal ideation, while cannabis problems linked to mania and dissociation. Somatic symptoms were significantly more central in co-users. Age did not moderate these relationships.
Why it matters
Knowing that alcohol and cannabis problems connect to different mental health symptoms — anxiety/suicidality vs. mania/dissociation — allows clinicians to screen for specific psychiatric risks based on which substances a patient uses.
The numbers in context
740 participants (16-81 years). Co-users higher on all mental health measures (all p≤0.001). Alcohol problems→anxiety (r=0.03), personality (r=0.01), suicidal ideation (r=0.01). Cannabis problems→mania (r=0.05), dissociation (r=0.02). Somatic centrality: 1.31 in co-use vs 0.17 in alcohol-only.
How the study worked
Network analysis of 740 participants aged 16-81 (446 alcohol users, 294 alcohol-cannabis co-users) from online international survey. Mental health assessed via DSM Level 1 Cross-Cutting Symptom Measure; substance use via AUDIT and CUDIT-R.
What this study cannot tell us
Cross-sectional design cannot determine causation. Online convenience sample from multiple countries may not be representative. Network edges are associations, not causal pathways. Relatively small co-use group (294).
How to read the evidence
Innovative network methodology with broad age range, limited by cross-sectional design, convenience sample, and moderate co-user group size.
When this study was published
Published 2026, using data from English and Dutch-speaking participants across multiple countries.
The bigger picture
The stability of these substance-symptom patterns across ages suggests they reflect fundamental neurobiological relationships rather than cohort effects — meaning these clinical associations are likely to hold across generations.
Questions still open
- Do the alcohol-anxiety and cannabis-mania links reflect shared neurobiology or common risk factors? Should dual-use screening protocols differ from single-substance ones? Could treating specific mental health symptoms reduce substance-specific use?
Common questions
Do alcohol and cannabis affect mental health differently?
Does age change how substances affect mental health?
Read the original research
Understanding the interplay between alcohol use, cannabis use and mental health across the lifespan: A network analysis.
Addiction (Abingdon, England)
Citation
Macedo, Inês; Kroon, Emese; Colyer-Patel, Karis; Freichel, René; Romein, Christophe; Pasion, Rita; Barbosa, Fernando; Cousijn, Janna. (2026). Understanding the interplay between alcohol use, cannabis use and mental health across the lifespan: A network analysis.. Addiction (Abingdon, England). https://doi.org/10.1111/add.70324
Explore the wider topic
- LGBTQ+ and Cannabis: Higher Use Rates and Recovery
- Cannabis-Induced Psychosis: What It Is, Who's at Risk, and What to Do
- BetterHelp, Cerebral, and Online Therapy: Honest Review
- Quitting Weed with ADHD: Why It Is Harder and What Actually Helps
- Quitting Weed with Depression: What You Need to Know
- Quitting Weed with PTSD: A Practical Guide
- Self-Medicating with Weed: Why It Works Until It Doesn't
- Weed and OCD: Self-Medicating Intrusive Thoughts
- Weed and PTSD: What the Research Actually Shows
- Weed and Childhood Trauma: ACEs, Self-Medication, and the Path to Real Healing
- Weed and Suicidal Thoughts: What You Need to Know
- Why Do You Get the Spins When You Mix Weed and Alcohol
- THC and Alcohol: Why Crossfading Hits So Much Harder