U of G researcher warns students about the negative effects of marijuana use
It is common knowledge that cannabis is very popular among teens and young adults. Users often mention its soft effects compared to alcohol and hard drugs Plus, the lack of nicotine leads people to believe it is not addictive. The truth is, while the negative outcomes of alcohol and hard drugs are well understood — liver damage, addiction, overdose, etc. — the negative effects of cannabis are usually denied. To clear up the fog (pun intended), I interviewed the University of Guelph’s principal investigator, Dr. Jibran Khokhar, who studies the linked effects of cannabis use with other substances (such as alcohol and nicotine), as well as the effects of cannabis use in adolescence, on mental illnesses later on in life.
Khokhar has been studying neuropharmacology — the study of how drugs affect cellular processes in the nervous system — for many years. At the University of Toronto and Dartmouth College, he specifically looked at the co-use of different substances on disease. Since joining U of G 10 months ago, his lab has been studying the effects of co-use of substances on serious mental illnesses. Cannabis is one of the substances they study.
“Patients with schizophrenia or other serious mental illnesses use drugs at higher rates,” said Dr. Khokhar in an interview with The Ontarion. He added that “drug use by itself, during critical periods such as adolescence, has been associated with the development of serious mental illness. Even though the association is there, we can’t really know for sure [if it causes the illness], or what the causal direction is. Whether it’s schizophrenia that causes substance use, or whether it’s substance use that causes schizophrenia.” This is the purpose of his lab work, to better understand the relationship between the two.
Khokar told The Ontarion that some of the key results his lab has discovered show that “adolescent exposure to drugs can result in long-term changes in both brain circuitry as well as reward related behaviours.” Other results have shown that “animal models of schizophrenia show a dysfunction in their brain reward circuit that make them more likely to use substances.”
In order to get these results, Khokhar explained that he and his team are approaching this question from both “a developmental angle” and “through genetic models.”
One of the new directions of the research that Khokhar does is his methodology; he studies the effects of two substances together as opposed to one at a time. Khokhar said the reason for this comes from epidemiological studies.
He goes on to say that many adolescents use two drugs simultaneously. Khokhar noted that “with alcohol and nicotine it’s something like 80 per cent of patients that have an alcohol use disorder also have tobacco use disorder and vice versa. So there’s a lot of poly-drug use, as it is often called.” Many students commonly use alcohol and cannabis together. Khokhar warns students that the effects of multiple drugs together are more intense than using each one individually. He even referred to this phenomenon as “scary.”
Cannabis is a common way of self-medicating anxiety and depression. The self-medication hypothesis can somewhat debunk this popular method. Khokhar stated that evidence isn’t in support of self-medicating with cannabis, bringing up Dr. Tony P. George’s work, who is a researcher at CAMH. “[George’s research] has shown that if you take somebody who has schizophrenia, and who uses cannabis, and if you can get them to be abstinent from their cannabis, you actually see an improvement in their depressive [and] cognitive symptoms.”
The true focus of Khokhar’s lab is studying the long-term effects of cannabis use. He explained that “brain-imaging studies have [shown] that cannabis use can alter brain structure and function in the long-term.”
Khokhar’s lab research has a direct impact on cannabis legislation. He and his team recently attended a diverse panel discussion held at Western University regarding cannabis legalization. Among the panel members were a philosopher, two pharmacologists, a medical marijuana doctor, and an MPP from London, Ont. Khokhar found that “the big take home that I came away from this with is that we need a lot more research. And hopefully, the Government [of Canada] and universities will see that and support research [in this field].”
His general view on the legalization of cannabis? He sees this as “a 30 million people [sic] experiment.” His final comments expressed that he is looking to the future social implications that the legalization of marijuana will bring about. Said Khokhar, “I’m hoping we come away from it [with] a net positive.”
If you’re interested in learning more about the research available on this subject, Khokhar recommends looking for reliable sources, such as PubMed. To find out more about the specific research conducted in Khokhar’s lab, you can follow him or his lab on Twitter, or personally get in touch with him at jkhokhar@uoguelph.ca. To stay up to date with new findings in Khokhar’s lab you can follow his personal and lab twitter accounts: @DrJKhokhar and @JKhokharLab.
Photo provided by Jibran Khokhar