Combining MDMA and Cannabis Produced Lasting Immune System Changes in Regular Users
People who used both MDMA and cannabis showed sustained decreases in immune cells and increased infection rates over a year, with cannabis-only users showing intermediate effects.
Quick Facts
What This Study Found
Researchers followed three groups over one year with assessments at baseline, 6 months, and 12 months: 37 people who used both MDMA and cannabis, 23 cannabis-only users, and 34 non-using controls.
The MDMA-cannabis group showed significantly decreased IL-2 (a pro-immune cytokine) and increased TGF-beta1 (an anti-inflammatory marker), along with reduced total lymphocytes, CD4 cells, and natural killer cells. The cannabis-only group showed intermediate changes between the MDMA-cannabis users and controls.
These immune alterations persisted across all three time points, suggesting they were sustained rather than acute effects. Regular MDMA-cannabis users had significantly more mild infections (colds, respiratory issues) than occasional users or controls.
No difference was found between regular and occasional MDMA users for the immune markers, though infection rates were higher in regular users.
Key Numbers
37 MDMA+cannabis users, 23 cannabis-only users, 34 controls. Decreased: IL-2, total lymphocytes, CD4 cells, NK cells. Increased: TGF-beta1. Higher mild infection rate in regular MDMA+cannabis users. Immune changes sustained over 12 months.
How They Did This
Longitudinal prospective study with three cross-sectional evaluations at baseline, 6 months, and 1 year. Cell-mediated immune function was assessed through cytokine panels and immune cell counts. Infection history was documented through self-report and medical records.
Why This Research Matters
Most drug interaction research focuses on acute effects. This study showed that combined MDMA and cannabis use produced immune system changes that persisted over at least a year and translated into measurable health consequences (more infections).
The Bigger Picture
This study raised important questions about the cumulative immune effects of polydrug use. While cannabis alone showed intermediate immune effects, the combination with MDMA produced more pronounced and sustained immune suppression, a pattern relevant given the common co-use of these substances in recreational settings.
What This Study Doesn't Tell Us
Polydrug users often use additional substances not accounted for in this study. Self-reported drug use may be inaccurate. The observational design cannot confirm that drug use caused the immune changes rather than pre-existing differences. Sample sizes were relatively small.
Questions This Raises
- ?Do the immune changes reverse with sustained abstinence?
- ?Does cannabis alone at higher use levels produce similar immune suppression?
- ?Are the increased infections clinically significant or limited to minor illnesses?
Trust & Context
- Key Stat:
- Immune changes persisted over 12 months in MDMA+cannabis users
- Evidence Grade:
- This is a longitudinal cohort study with three time points and appropriate control groups, providing moderate evidence though limited by small sample sizes and observational design.
- Study Age:
- Published in 2007. Research on cannabis-drug interactions and immune effects has continued, though MDMA-cannabis immune interaction studies remain limited.
- Original Title:
- Combined immunomodulating properties of 3,4-methylenedioxymethamphetamine (MDMA) and cannabis in humans.
- Published In:
- Addiction (Abingdon, England), 102(6), 931-6 (2007)
- Authors:
- Pacifici, Roberta, Zuccaro, Piergiorgio, Farré, Magí(6), Poudevida, Sandra, Abanades, Sergio, Pichini, Simona, Langohr, Klaus, Segura, Jordi, de la Torre, Rafael
- Database ID:
- RTHC-00286
Evidence Hierarchy
Follows a group of people over time to track how outcomes develop.
What do these levels mean? →Frequently Asked Questions
Does cannabis alone affect the immune system?
In this study, cannabis-only users showed immune changes that fell between the MDMA+cannabis group and controls, suggesting cannabis alone may have some immune effects, though less pronounced than the combination.
What kinds of infections increased?
The study documented mild infections such as colds and respiratory infections. Serious or life-threatening infections were not reported.
Read More on RethinkTHC
- CBD-oil-quality-guide
- anxiety-medication-after-quitting-weed
- cannabis-chemotherapy-nausea
- cannabis-chronic-pain-research
- cannabis-epilepsy-CBD-Epidiolex
- cbd-anxiety-research-evidence
- cbd-for-weed-withdrawal
- cbd-vs-thc-difference
- medical-benefits-of-cannabis
- quitting-weed-before-surgery
- quitting-weed-medication-interactions
- quitting-weed-pregnancy
- quitting-weed-pregnant
- seniors-older-adults-cannabis-risks-medications
- weed-breastfeeding-THC-breast-milk
- thc-and-antibiotics-safe-cannabis-while-on
- thc-and-caffeine-most-common-drug-combo
- thc-and-diabetes-medication-blood-sugar
Cite This Study
https://rethinkthc.com/research/RTHC-00286APA
Pacifici, Roberta; Zuccaro, Piergiorgio; Farré, Magí; Poudevida, Sandra; Abanades, Sergio; Pichini, Simona; Langohr, Klaus; Segura, Jordi; de la Torre, Rafael. (2007). Combined immunomodulating properties of 3,4-methylenedioxymethamphetamine (MDMA) and cannabis in humans.. Addiction (Abingdon, England), 102(6), 931-6.
MLA
Pacifici, Roberta, et al. "Combined immunomodulating properties of 3,4-methylenedioxymethamphetamine (MDMA) and cannabis in humans.." Addiction (Abingdon, 2007.
RethinkTHC
RethinkTHC Research Database. "Combined immunomodulating properties of 3,4-methylenedioxyme..." RTHC-00286. Retrieved from https://rethinkthc.com/research/pacifici-2007-combined-immunomodulating-properties-of
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.