Rerouting mental health in Africa
- Beth Amato
Africa has the world’s most diverse genome research, which holds potential for precision medicine and revolutionising mental health treatment.
After her close friend died by suicide in 2022, Dr Vivien Chebii, a postdoctoral researcher at the Sydney Brenner Institute for Molecular Bioscience (SBIMB), switched her genetic research work from livestock to mental health. She’d experienced firsthand the wrecked lives left in the wake of this tragic loss.
In Africa, where an estimated 116 million people live with mental illness, the losses mount. One of the reasons is the dearth of information about the unique causes of mental illness amongst Africans.
Most of what we know about the genetic causes of mental illness, its diagnostic tools and the safety and efficacy of treatment options, has been studied predominantly in European populations. This is despite Africa being home to the richest and most diverse human genome.
Research into African genetics and disease profiles and the potential of precision medicine is growing exponentially worldwide.
“If you have more information about the African genome, it benefits all populations. What we are beginning to discover about genetic variants in diseases in African populations is a major leap in genetic science and public health,” says Prof. Michèle Ramsay, Director of the SBIMB.
Drugs affect African populations differently
Senior Scientist at the SBIMB, Profesor Collen Masimirembwa’s discovery of a genetic variation in African populations revealed that the side effects of the HIV drug Efavirenz (EFV) – which include rashes, depression and suicidal tendencies – were worse for Africans than patients on a standard dose, determined using European genomic data.
Masimirembwa found that many Zimbabwean and Botswanan individuals have a genetic variant that increases the metabolism of EFV, rendering the standard dose toxic for them. Following this discovery, lower doses resulted in increased compliance and improved viral control. In Botswana, genomic studies that showed that about 13.5% of the population would be unable to effectively utilise EFV-based therapies, lead to a change in the country’s HIV management policy in favour of the drug Dolutegravir.
“We uncovered the genetic reasons for these responses and therefore advocated for the need to consider Africa’s genomic diversity in the clinical development of new medicines and policies. This improves health systems significantly,” says Masimirembwa.
In the wake of her friend’s suicide, Chebii was also contending with how mental disorders co-occur in Africa with other diseases, such as hypertension and diabetes. Many people who are being treated for HIV and TB also have hypertension and other cardiometabolic disorders. Could it be that they share the same genetic pathways? Understanding this could help determine whether the various medications are working together effectively.
The genetics of depression in Africa
Research shows that postpartum complications, ageing, imprisonment, unwanted pregnancy, cardiovascular diseases, HIV, drug abuse and conflicts make up the main risk factors for depression in sub-Saharan Africa. However, mental illness is a complex interplay between environmental factors and genetics and so Chebii and 20 researchers from across South Africa, Ethiopia, Nigeria, Malawi and the UK who are members of the Depression Genetics in Africa consortium (DepGenAfrica) are trying to unravel the genetics of depression in more than 10 000 individuals.
“To our dismay we find that, unlike in other areas of health research, critical diagnostics, including screening tools, neuroimaging equipment and genetic research facilities, are prohibitively expensive for scientists and clinicians working in Africa,” says Chebii.
Yet, the World Health Organization’s (WHO)s 2017 Global Health Estimate reports that Africa accounts for around 10% of the global burden of mental disorders. However, the figures are likely understated due to widespread misdiagnosis, underdiagnosis and gaps in data.
Chebii says, “Scientists in African countries already struggle because of inadequate funding, insufficient research infrastructure, a shortage of researchers and lengthy waiting times for ethical approval. It’s high time that the world took steps to combat these inequities.”
New frontiers in drug delivery
More homegrown solutions are emerging in Africa. Wits University is building Africa’s first comprehensive genomic database and simultaneously developing targeted drug delivery technologies that are patient-centric and designed for African healthcare settings.
The Wits Advanced Drug Delivery Platform (WADDP) is actively researching innovative nanomedicines for treating depression, psychosis and a range of neurological diseases.
“The treatments for such diseases are often inadequate, mainly due to the restrictive blood-brain barrier. We are trying to fill the innovation gap. Nanotechnology provides many promising solutions to counter the challenges in conventional neurotherapy,” says Professor Yahya Choonara, the Director of the Platform.
“Traditional oral or injectable drugs, currently also the only two ways available for patients to take the medication, circulate throughout the body, not just the brain,” says Choonara. Furthermore, medication – especially some classes of antidepressants – can take weeks to show benefits. This slow relief and other side effects make patients more likely to stop their treatment.”
Tailored and targeted treatment
In response, Choonara and his team have patented a delivery device that uses a ‘melt-dispersion’ technique to deliver antipsychotic medication such as chlorpromazine to the brain via nanocapsules in a system that is both effective and biodegradable. The nanocapsules are delivered to the brain’s frontal lobe using an implant for targeted delivery. When tested in the lab, the nanocapsules successfully delivered the psychiatric medication to the brain over an extended period and demonstrated minimal toxicity to brain-like cells.
“This system shows strong potential for long-term, site-specific treatment of psychiatric disorders, reducing the need for frequent dosing and improving patient outcomes,” says Choonara. “Currently, the technology is being pivoted to a simpler nose-to-brain delivery strategy. This is a significant opportunity for low-resourced healthcare settings where conventional mental health treatment is notoriously difficult to get right.”
- Beth Amato is a freelance writer.
- This article first appeared in?Curiosity,?a research magazine produced by?Wits Communications?and the?Research Office.
- Read more in the 19th issue, themed #Disruption, which explores the crises, tech, research, and people shaking up our world in 2025.