A new study from the University of the Basque Country (UPV/EHU) has uncovered potential clues in the blood that could help predict whether cannabis users might develop schizophrenia. Conducted by the university’s Neuropsychopharmacology and IBeA research groups, the research, published in the journal Scientific Reports, delves into the complex relationship between cannabis use and psychiatric disorders. By analysing fatty acid profiles in blood samples, the team has identified distinct differences that could serve as biomarkers, offering hope for earlier interventions and a deeper understanding of these conditions.
Cannabis remains one of the most widely used substances globally, with an estimated 228 million people aged 15 to 64 partaking. Its popularity, however, comes with risks. Research has long established that cannabis use, particularly when begun in adolescence, significantly increases the likelihood of developing schizophrenia. Around 10% of users will face cannabis use disorder in their lifetime, a condition marked by an inability to control consumption despite negative consequences. Intriguingly, the overlap between cannabis use disorder and schizophrenia is substantial. Nearly a third of schizophrenia patients meet the criteria for cannabis use disorder, while up to 42% of those with schizophrenia grapple with this dual diagnosis.
The UPV/EHU study set out to unravel why some cannabis users develop schizophrenia while others do not, despite similar exposure. “We wanted to shed light on the biological mechanisms behind this,” said Leyre Urigüen, the study’s coordinator. “Our aim was to detect potential biomarkers in the blood that could help predict the risk some people have of developing a psychiatric disorder such as schizophrenia if they use cannabis.” To achieve this, the researchers examined blood samples from four distinct groups, individuals with schizophrenia who abstained from cannabis, those with cannabis use disorder alone, those with both conditions, and a control group free of psychiatric issues or drug use.
The findings were striking. “We found considerable differences between these groups of individuals,” Urigüen explained. “By comparing the quantities of certain metabolites (fatty acids), we were able to perfectly differentiate between the three patient populations.” This suggests a unique metabolic fingerprint for each group. Notably, certain fatty acids stood out as potential markers separating cannabis users from those with schizophrenia or the dual diagnosis. “These molecules could potentially be biomarkers,” she added, highlighting their promise as predictive tools.
This discovery is a significant step forward, but Urigüen cautions that it is just the beginning. “I think it is important to be capable of finding blood biomarkers that can help predict the risk of developing a psychiatric disorder, such as schizophrenia due to cannabis use, and this study has proven to be the start of this way forward,” she said. However, she emphasized the need for larger studies to validate these findings. The current research involved a relatively small cohort, and broader testing is essential to confirm whether these fatty acids can reliably predict risk across diverse populations.
Beyond identifying potential biomarkers, the study also refined a method for analysing plasma lipidomics, the comprehensive study of fatty acids in blood. This approach, developed in collaboration with the IBeA research group led by Professor Nestor Etxebarria, offers a reproducible framework for future investigations. “We are proposing a way of working that can be replicated by other groups,” Urigüen noted, “and that way, headway can be made in the specification of these metabolites.” The two teams are already exploring additional angles, pooling their expertise to tackle unanswered questions about the interplay between cannabis and mental health.
For now, the research opens a door to a future where a simple blood test might reveal an individual’s vulnerability to schizophrenia before symptoms emerge. Such a tool could transform how clinicians approach cannabis-related risks, enabling targeted prevention strategies. As cannabis use continues to rise worldwide, studies like this underscore the urgent need to understand its long-term effects, not just on the mind, but on the body’s very chemistry.
