A groundbreaking genetic study, published in a renowned medical journal in 2023, has delved deep into the association between cannabis use and psychotic disorders such as schizophrenia and bipolar disorder. The study harnesses the power of genome-wide association studies (GWAS), mendelian randomisation, and polygenic scoring to provide new insights into this complex relationship.
Unpacking the Research
The aim of this research was twofold: to investigate the genetic architecture of cannabis phenotypes (lifetime cannabis use and cannabis use disorder) and psychotic disorders, and to test for potential causal relationships between these variables.
Importantly, the study discovered differences in the genetic makeup of schizophrenia, bipolar disorder, and cannabis phenotypes. It revealed that these disorders have a greater heritability and are more polygenic than cannabis use disorder.
“The polygenicity of lifetime cannabis use or cannabis use disorder has not been previously estimated,” researchers noted.
![](https://cannabisnewsdotau.files.wordpress.com/2023/05/gianni.drm_a_dna_double-helix_structure-1.png?w=1024)
The Results Unearthed
The key findings of the study provide robust evidence for a shared genetic basis between psychotic disorders and cannabis phenotypes, with shared loci identified across the genome. In simpler terms, if an individual has a genetic predisposition to cannabis use, they are also more likely to develop psychotic disorders, and vice versa.
One of the more interesting findings was the evidence of bidirectional causal effects. This means that not only does a genetic predisposition to psychotic disorders increase the likelihood of cannabis use, but the genetic tendency towards cannabis use also increases the risk of developing psychotic disorders.
The study also found that polygenic scores, which represent the combined effect of many genes, can be used to predict the likelihood of an individual developing bipolar disorder and schizophrenia.
The Clinical Significance of the Findings
According to the researchers, these results could have several important implications for clinical practice. One such implication is that reducing cannabis use through public health initiatives could potentially prevent the development of psychotic disorders.
Further, the genetic overlap suggests a subgroup of individuals who are at a high genetic risk for both psychosis and cannabis use. The authors noted, “Early identification of this subgroup is important for targeted interventions.”
![](https://cannabisnewsdotau.files.wordpress.com/2023/05/gianni.drm_a_computer_screen_displaying_a-1.png?w=1024)
Future Directions and Limitations
Despite the intriguing findings, the study is not without its limitations. The research points out that potential bias may be present due to the inclusion of cannabis users in the GWASs for bipolar disorder and schizophrenia. Also, the power of the cannabis use disorder GWAS was noted to be low, possibly impacting the validity of the findings.
Moreover, the researchers suggest that there’s still a great deal of work needed to tease apart the intertwined influences of genetics and environment.
Conclusion
In conclusion, this landmark study has cast a new light on the relationship between cannabis use and psychotic disorders, highlighting a shared genetic link and possible bidirectional causality. These findings are a significant stride towards informing public health policies and providing personalised care for patients.
Here is a direct quote from the study’s conclusion to encapsulate the research’s findings: “Our study used the largest genetic datasets and various genetic approaches to evaluate the relationship between cannabis phenotypes and psychotic disorders. The findings support a shared genetic basis, with bidirectional causality, which helps to explain the well-established co-occurrence of psychotic disorders and cannabis use. A subgroup of individuals will have a high genetic risk of developing a psychotic disorder and using cannabis, supporting targeted public health efforts to reduce cannabis use particularly among these individuals at high risk. Identified shared genetic loci could also aid in treatment efforts. Ultimately, these results could help inform public health policies and aid in pursuits of customised care for patients.”
Remember, while the study provides new insights into the genetic basis of cannabis use and psychotic disorders, it also highlights the complex interplay between genetic and environmental factors. As cannabis enthusiasts, understanding these genetic predispositions can help us have educated conversations about cannabis legalisation and public health policy which are current hot topics in Australia.
Stay tuned for more updates from the fascinating world of cannabis research.