Effective antidepressant medicine with an important ingredient from cannabis – though, of course, without any potential for abuse – is one of the dreams of Sâmia Joca, who carries out research into neuropharmacology in her new position of honorary professor at The Department of Clinical Medicine, Aarhus University.

2017.02.02 | Nanna Jespersgård

“The Translational Neuropsychiatry Unit has a collection of genetically depressed rats, which combined with the highly developed molecular and imaging technologies, means we can test the hypothesis in a way that would not be possible in Brazil. So in this way we bring together our own important contribution to the field," says Sâmia Joca.

“The Translational Neuropsychiatry Unit has a collection of genetically depressed rats, which combined with the highly developed molecular and imaging technologies, means we can test the hypothesis in a way that would not be possible in Brazil. So in this way we bring together our own important contribution to the field," says Sâmia Joca.

The cannabis ingredient cannabidiol, which is one of 60 cannabinoids in the hemp plant, has shown an antidepressant-like effect on rodents.  If further confirmed in humans, it should be possible to use this effect for improving depression treatment.

Sâmia Joca, honorary professor of neurobiology at the Translational Psychiatry Unit under the Department of Clinical Medicine at Aarhus University, does not waver when explaining how far she and her research colleagues have come in their exploration of new mechanisms for finding better therapeutics to help the patients who currently have no or only limited effect of antidepressants.

"The problem is that existing antidepressant medicine is not good enough. It takes 3-5 weeks before working, fifty per cent of patients will not be completely cured even though they experience an improvement, and the medicine does not work at all on thirty per cent of the population,” says Sâmia Joca about the reason for studying the treatment perspectives in ingredients from cannabis as well as the anaesthetic ketamine. 

"Cannabidiol is a substance that has a well-documented effect on humans with epilepsy, psychosis and anxiety. Therefore, in collaboration with Professor Gregers Wegener and colleagues in Brazil, I am investigating the neurobiological mechanisms that underlie the antidepressant effect of cannabidiol," says Sâmia Joca.

She explains that cannabidiol is one of at least 60 active cannabinoids that have been identified in cannabis, which comprises a total of more than 500 components, saying this to emphasise that cannabidiol effects should not be confused with neither cannabis nor hemp plants effects in general.

Genetically depressed rodents

The Brazilian researcher highlights both Aarhus facilities and animal models as a prerequisite for proceeding with studies about the potential involvement of the endocannabinoid system in mental disorders. On the other hand, the endocannabinoid system – and cannabidiol in particular – is an area where Sâmia Jocas’ home university, the University of São Paulo, has a tradition that goes back further than in Denmark. Sâmia Joca calls it a win-win collaboration:       

In addition to the cannabinoid system, Sâmia Joca is also interested in how stress can lead to depression and anxiety as well as in the molecular mechanisms that cause the anaesthetic ketamine to accelerate the effect of antidepressant medicine. This is also an area that Sâmia Joca hopes can contribute to the development of more effective – in this case rapid-acting – types of medicine, though in the knowledge that it will take many years before the results of the research are translated into an approved prescription drug.

Abuse of research results

Sâmia Joca is also aware that cannabis in medical contexts is a political hot potato in both Denmark and at home in Brazil, where she has seen her own research misused in a context that was “far out”:

"As a postdoc I chanced upon a blog that used a study in which I was involved to argue in favour of using cannabis as a narcotic. That is of course a misunderstanding as I had only studied canabidiol, which I explained to the blogger," says Sâmia Joca.

She emphasises that regarding treatment of depression, researchers are nowhere near utilising the cannabis component which is known for its euphoriant properties – called tetrahydrocannabinol but probably best known as THC.

"In my role of honorary professor I also hope to be able to strengthen talent development between Denmark and Brazil, so that we can over time secure more research-based partnerships in both countries," says Sâmia Joca. In addition to her, Aarhus University has had two PhD students from Brazil affiliated with The Translational Neuropsychiatry Unit. 

Contact:

Honorary Professor Sâmia Joca
Aarhus University, Department of Clinical Medicine, Translational Neuropsychiatry Unit
University of São Paulo, School of Pharmaceutical Sciences of Ribeirão Preto
Email: samia@usp.br or sjoca@clin.au.dk
Tel.: (+45) 7847 1120

Professor Gregers Wegener, MD, PhD, DMSc
Aarhus University, Department of Clinical Medicine, Translational Neuropsychiatry Unit
Email: wegener@clin.au.dk
Tel.: (+45) 7847 1112
Mobile: (+45) 5171 7403