The Unspoken Risk

How prolonged cannabis use and high-THC strains are triggering psychosis in young people — and what wealthy African families need to know about navigating treatment, stigma, and the law.

It begins quietly. A son who was always outgoing becomes withdrawn and suspicious. A daughter who excelled at university starts speaking in ways that do not quite make sense. Sleep patterns collapse. Conversations become strange, circuitous, frightening. And somewhere in the background, there is cannabis — a substance that many young people, and many parents, still consider essentially harmless.

The clinical evidence tells a very different story. The relationship between cannabis use and psychosis, particularly among adolescents and young adults, is now supported by an extensive and growing body of international research. For families in Lagos, Accra, Abuja, Nairobi, and other major African cities, this evidence carries particular urgency — because the legal, cultural, and clinical landscapes surrounding cannabis in these regions make it extraordinarily difficult to seek help.

At Behavioural Wealth, we have direct experience supporting wealthy families through exactly these crises: cannabis-related psychotic episodes in young people, where the family must simultaneously manage a psychiatric emergency, protect reputations, and navigate legal systems that criminalise the very substance at the heart of the problem. This blog examines the clinical reality, the African context, and how we can help.

The Clinical Evidence: Cannabis and Psychosis

The link between cannabis use and psychotic disorders is no longer a matter of serious scientific dispute. It is a question of degree, mechanism, and vulnerability — but the core association is well established across decades of longitudinal research.

What the Research Shows

A landmark 2024 study published in Psychological Medicine by researchers at the Centre for Addiction and Mental Health (CAMH) and the University of Toronto estimated that teenagers who use cannabis are at eleven times higher risk of developing a psychotic disorder compared to non-using peers. This finding significantly exceeds previous estimates, which the study’s authors attribute to the fact that earlier research relied on data from an era when cannabis was far less potent than today’s products (CAMH, 2024).

A sweeping systematic review published in the Annals of Internal Medicine in 2025, analysing 99 studies comprising over 221,000 participants, confirmed that high-concentration THC products are associated with unfavourable mental health outcomes, particularly for psychosis, schizophrenia, and cannabis use disorder. Researchers defined high-concentration products as those exceeding 10% THC per serving — a threshold that much of today’s commercially available cannabis easily surpasses (Rittiphairoj et al., Annals of Internal Medicine, 2025).

A comprehensive 2024 meta-analysis published in Nature Mental Health, pooling 162 studies across more than 210,000 cannabis-exposed individuals, found that approximately one in five users in observational studies experienced cannabis-associated psychotic symptoms. The study identified younger age and THC administration as significant predictors of psychotic episodes (Schoeler et al., Nature Mental Health, 2024).

The dose-response relationship is also well documented. A 2024 review in PMC notes that multiple studies have demonstrated that a single administration of THC in healthy subjects can induce a wide array of positive, negative, and general symptoms of psychosis, while CBD (cannabidiol), the other major constituent of cannabis, appears to have no such effect and may even have antipsychotic properties (PMC, Cannabis and Psychopathology, 2024).

The Potency Crisis

What makes this moment particularly dangerous is the dramatic escalation of THC potency. Average THC concentrations in cannabis have quadrupled in the United States since the 1990s, rising from approximately 4% to 15%, and doubled in Europe from 6% to 11% (PMC, Assessing Cannabis Use in People with Psychosis, 2024). Concentrated products such as wax, shatter, and oils can reach THC levels of 60–90%.

This potency escalation has had measurable consequences. Between 2000 and 2016, the incidence of cannabis-induced psychosis increased by 67% in Norway, 115% in Denmark, and 238% in Sweden (PMC, 2024). In Canada, emergency department presentations for cannabis-induced psychosis doubled between 2015 and 2019. Critically, many of these individuals subsequently go on to develop a persistent psychotic disorder: a Danish registry study found that approximately half of patients with cannabis-induced psychosis eventually transitioned to a diagnosis of independent psychosis (PMC, Cannabis and Psychopathology, 2024).

Why Young People Are Most Vulnerable

The adolescent and young adult brain is uniquely susceptible to cannabis-related harm. The prefrontal cortex — responsible for decision-making, impulse control, and executive function — does not fully mature until the mid-twenties. THC disrupts the hippocampus (critical for memory formation), reduces grey matter volume in the prefrontal cortex, and impairs white matter connectivity between brain regions (Psychology Today, 2024).

The CAMH study found a striking result: while teenagers who used cannabis faced an eleven-fold increased risk of psychotic disorders, no association was found between cannabis use and psychotic disorders in people aged 20 to 33. As one researcher not involved in the study observed, there appears to be a window of brain development during which cannabis use is uniquely dangerous for psychosis risk (NBC News, 2024).

This is not to suggest that cannabis is safe for older users — but the evidence is clear that the adolescent brain is particularly vulnerable, and that the consequences of use during this developmental window can be permanent and devastating.

The African Evidence: West and East Africa

While the majority of research on cannabis and psychosis has been conducted in the Global North, an emerging body of work from West and East Africa is beginning to illuminate the issue in the region. The findings are consistent with international evidence — and are made more urgent by the scale of youth substance use across the continent.

The INTREPID II Study: Nigeria (Ibadan)

The International Programme of Research on Psychotic Disorders (INTREPID II), a landmark case-control study conducted between 2018 and 2020 and published in Psychological Medicine, examined patterns of cannabis use and associations with psychosis in three Global South settings, including Ibadan, in Oyo State, Nigeria. The study, conducted through the WHO Collaborating Centre for Research and Training in Mental Health at the University of Ibadan, recruited over 200 individuals with untreated psychosis alongside matched controls. Cannabis exposure was measured using the WHO’s Alcohol, Smoking and Substance Involvement Screening Test (ASSIST). This study is significant because it represents one of the first rigorous investigations of the cannabis–psychosis relationship in a West African clinical population, and its findings are consistent with the broader global evidence base (Morgan et al., Psychological Medicine, 2023).

The NeuroGAP-Psychosis Study: Kenya and East Africa

The Neuropsychiatric Genetics of African Populations (NeuroGAP) Psychosis study, one of the largest case-control studies of its kind in Africa, has investigated substance use among people with and without psychosis across multiple Kenyan sites, including Kilifi County, Mombasa, and the Moi Teaching and Referral Hospital network in the Rift Valley. Published in PMC (2024), the Kenyan data confirmed that cannabis use was higher among individuals with psychosis than among controls, consistent with international evidence of a dose-dependent relationship between cannabis exposure and psychotic illness (PMC, NeuroGAP-Psychosis Kenya, 2024).

A further large-scale 2025 study published in Schizophrenia Research utilised the NeuroGAP dataset across four African countries — South Africa, Ethiopia, Kenya, and Uganda — to investigate substance use in people with psychotic disorders. The study found significant cross-country variations in cannabis use among individuals with schizophrenia and bipolar disorder, with males showing consistently higher rates of consumption. Importantly, the study confirmed that cannabis was one of the most frequently used substances among people with psychotic disorders across all four countries (Campbell et al., Schizophrenia Research, 2025).

A Nairobi-Led Meta-Analysis

In 2021, Dr Sarah Kanana Kiburi of Mbagathi Hospital, Nairobi, led a systematic review and meta-analysis published in Substance Abuse examining whether specific factors moderate the relationship between adolescent cannabis use and psychosis risk. The review confirmed the elevated risk and explored moderating variables including age of initiation, frequency of use, and potency. This East Africa-led research contributed directly to the global evidence base and underscored the relevance of the cannabis–psychosis link for African populations (Kiburi et al., Substance Abuse, 2021).

Youth Substance Use Across Sub-Saharan Africa

A 2024 systematic review and meta-analysis published in Frontiers in Psychiatry examined substance use among young people across sub-Saharan Africa, drawing on 60 studies. The review found that the lifetime prevalence of any substance use among young people was 21%, with Southern Africa recording the highest rates (25%), followed by East Africa (22%) and West Africa (17%). Nigeria recorded the highest lifetime prevalence of sedative use at 19%, and cannabis was identified as one of the most commonly used substances across the continent. The study’s authors highlighted that socio-cultural and economic factors in low- and middle-income settings create distinct challenges in addressing youth substance use (Frontiers in Psychiatry, 2024).

The Legal Minefield: Cannabis Laws in West and East Africa

For wealthy African families, a cannabis-related psychotic episode does not exist in a clinical vacuum. It unfolds within a punitive legal framework that criminalises the very substance involved — and that can have devastating consequences for a young person’s future, their family’s reputation, and their ability to access appropriate care.

Nigeria

Cannabis is entirely illegal in Nigeria for both recreational and medical purposes. Under the National Drug Law Enforcement Agency (NDLEA) Act, possession of cannabis carries a minimum sentence of 15 years and a maximum of 25 years’ imprisonment. Cultivation can attract sentences of 21 years to life — and historically, the death penalty was available under the 1966 Indian Hemp Act and the 1980s military Decree 20, though subsequent amendments removed capital punishment for most offences (Cannabis.org.ng, 2024; Hemppedia, 2024). Nigeria ranks as the third-highest consumer of cannabis globally, with 14% of adults using the plant regularly — yet the legal framework remains among the most punitive in the world (Leafwell, 2025). A bill to legalise cultivation and use was introduced in 2023 but failed to progress in the House of Representatives.

Ghana

Recreational cannabis remains strictly illegal in Ghana under the Narcotic Drugs (Control, Enforcement, and Sanctions) Law, 1990. Possession, sale, or use can result in sentences of up to 25 years’ imprisonment, and in some cases, the death penalty remains technically available for trafficking offences (Cannigma, 2023). In 2020, the government authorised a pilot programme for low-THC industrial hemp cultivation through the Narcotics Control Commission, but a subsequent Supreme Court ruling in 2022 struck down the enabling legislation as unconstitutional. Despite these strict laws, cannabis use remains widespread, particularly among young people (High Life Global, 2025).

Kenya and East Africa

Cannabis is illegal in Kenya under the Narcotic Drugs and Psychotropic Substances (Control) Act. Possession, cultivation, and trafficking carry significant criminal penalties. Despite this, a 2017 nationwide survey found that a substantial proportion of the population aged 15–65 experienced substance use disorders, with over 10% affected, and a further survey revealed that 20% of school-going children had used at least one substance at some point (PMC, NeuroGAP-Psychosis Kenya, 2024). Khat, which is legal in Kenya and culturally embedded, adds an additional layer of complexity to the substance use landscape.

The Implications for Wealthy Families

For a family of wealth and public standing, these legal frameworks create an impossible bind. A young person experiencing cannabis-related psychosis needs urgent psychiatric intervention — but seeking that intervention locally risks triggering criminal investigations, involving law enforcement, and creating a trail of documentation that could follow the individual for life. Hospital records, police reports, and the sheer porosity of information in tightly networked elite communities all conspire against the family’s ability to manage the crisis discreetly.

The result, far too often, is delay. Families attempt to manage the crisis internally, through spiritual intervention, or by sending the young person abroad with no clinical framework in place. By the time proper treatment is sought, the condition may have advanced significantly — and the window for optimal intervention may have narrowed.

How Behavioural Wealth Supports Families Through This Crisis

Behavioural Wealth exists to ensure that no family has to face this alone, and no young person’s future is compromised by the absence of a safe, private, clinically informed pathway to treatment.

We are not a treatment centre. We are specialist case managers and international treatment facilitators who stand alongside the family at every stage — from the first crisis call through to sustained recovery and reintegration. Here is how we help:

Immediate Crisis Response

When a young person experiences a psychotic episode linked to cannabis use, the first hours are critical. We provide rapid, confidential engagement with the family, conducting an initial assessment of the situation and developing a secure plan. All communications are encrypted. Where necessary, we coordinate consultations at undisclosed locations, ensuring that the crisis remains invisible to household staff, business associates, and the wider community.

Navigating Legal Exposure

We understand the legal frameworks governing cannabis in Nigeria, Ghana, Kenya, and across the region. Our role is to help families understand their exposure and take steps to protect the young person from criminal liability while securing the clinical care they need. This may involve facilitating a discreet departure from the jurisdiction, coordinating with trusted legal counsel, and ensuring that no unnecessary documentation is created that could later be used against the individual. We do not provide legal advice, but we work alongside legal professionals who specialise in these matters, ensuring a seamless and coordinated response.

International Treatment Matching

Cannabis-related psychosis requires specialist treatment that is rarely available within West or East Africa at the standard required. We identify and facilitate placement at world-leading psychiatric and addiction treatment programmes in the United Kingdom, Switzerland, the United States, South Africa, and other jurisdictions. Crucially, we match the programme to the individual: a first-episode psychosis in a 19-year-old requires a fundamentally different clinical approach from chronic cannabis use disorder with recurrent psychotic features in a 28-year-old. We ensure the right clinical fit, every time.

Dual-Diagnosis Expertise

The clinical evidence is clear that cannabis-related psychosis frequently involves dual or complex diagnoses: underlying anxiety, depression, trauma, or pre-existing vulnerability to psychotic illness that the cannabis has triggered or exacerbated. We work with treatment centres that specialise in precisely these intersections, where the addiction and the psychiatric condition are treated as inseparable components of a single clinical picture. Research consistently shows that integrated treatment of substance use and psychiatric disorders produces significantly better outcomes than addressing either in isolation (Frontiers in Psychology, 2025).

Cultural Competence and Family Support

We bring years of direct experience working with prominent families across Lagos, Accra, Abuja, Nairobi, and other major African cities. We understand the cultural dynamics that shape how these crises are experienced: the role of elder authority, the significance of spiritual and religious belief systems, the particular expectations placed on sons and daughters of prominent families, and the way that shame and stigma operate differently within different ethnic and national contexts. Our assessments account for all of these factors, ensuring that treatment is not only clinically excellent but culturally attuned.

We also provide dedicated support to the wider family. When a young person experiences a psychotic episode, parents, siblings, and extended family members are profoundly affected. Research confirms that family involvement and education are essential to sustained recovery (PMC, 2024). We facilitate family counselling, psychoeducation, and ongoing communication with the treatment team throughout the process.

Reintegration and Aftercare

Perhaps the most underappreciated phase of recovery is the return home. A young person who has received world-class treatment for cannabis-induced psychosis must then re-enter the very environment in which the crisis began — the same social circles, the same pressures, and potentially the same access to substances. We provide sustained case management during this critical period, coordinating local aftercare, monitoring wellbeing, managing family expectations, and helping the young person rebuild their life without exposure to the triggers that preceded the crisis.

What Parents Should Know: Warning Signs

Early intervention dramatically improves outcomes. Parents and family members should be alert to the following signs in a young person who may be using cannabis:

• Cognitive changes: Difficulty concentrating, declining academic or professional performance, disorganised thinking or speech.
• Perceptual disturbances: Hearing voices, seeing things that others cannot see, expressing beliefs that are clearly disconnected from reality.
• Paranoia and suspicion: Unfounded beliefs that they are being watched, followed, or conspired against.
• Social withdrawal: Retreating from friends, family, and activities they previously enjoyed.
• Emotional flatness or inappropriate affect: Laughing at nothing, showing no emotion in situations that would normally provoke one.
• Sleep disruption: Severe insomnia or dramatically altered sleep–wake cycles.
• Aggression or erratic behaviour: Uncharacteristic hostility, impulsivity, or risk-taking.

If these signs are present alongside known or suspected cannabis use, the situation should be treated with the same urgency as any other medical emergency. The earlier intervention occurs, the better the prognosis.

Breaking the Silence on Cannabis and Psychosis

Cannabis is not the harmless recreational substance that popular culture — and, increasingly, international legalisation movements — suggest it to be. For young people, and particularly for adolescents whose brains are still developing, high-potency cannabis use carries a real, clinically documented risk of triggering psychotic illness that can alter the course of a life.

In West and East Africa, where cannabis laws are punitive, stigma is intense, local treatment options are inadequate, and family reputation is inextricably linked to individual behaviour, the stakes for wealthy families are extraordinarily high. Delay, concealment, and improvisation are the enemies of recovery. What these families need is a trusted, experienced partner who can move swiftly, discreetly, and with clinical precision.

That partner is Behavioural Wealth.

If your son or daughter is experiencing the effects of cannabis use and you need confidential, expert guidance, we are here.

Behavioural Wealth

Case Management  ·  International Treatment Facilitation

Serving families in Lagos  |  Accra  |  Abuja  |  Nairobi  |  Johannesburg  |  and internationally

References

Belete, H., Mekonen, T., Espinosa, D.C. et al. (2023). Cannabis use in sub-Saharan Africa: a systematic review and meta-analysis. Addiction, 118(7), 1201–1215.

Campbell, M.L. et al. (2025). Sociodemographic influences on substance use in psychosis in an African cohort. Schizophrenia Research.

Cannabis.org.ng (2024). Nigeria Marijuana Laws 2024.

Cannigma (2023). Cannabis laws in Ghana.

Centre for Addiction and Mental Health (CAMH) (2024). New evidence suggests stronger link between teen cannabis use and psychotic disorders. Psychological Medicine.

Chesney, E. et al. (2024). Assessing Cannabis Use in People with Psychosis. Cannabis and Cannabinoid Research, 9(1), 49–58.

Frontiers in Psychiatry (2024). Substance use among young people in sub-Saharan Africa: a systematic review and meta-analysis.

Hemppedia (2024). Is Cannabis legal in Nigeria? – Update 2024.

High Life Global (2025). Is Cannabis Legal in Ghana? Laws, Penalties, and More.

Kiburi, S.K., Molebatsi, K., Ntlantsana, V. & Lynskey, M.T. (2021). Cannabis use in Adolescence and Risk of Psychosis: Are there Factors that Moderate this Relationship? Substance Abuse, 42(4), 527–542.

Leafwell (2025). Is Marijuana Legal in Nigeria?

Morgan, C. et al. (2023). Cannabis use and psychotic disorders in diverse settings in the Global South: findings from INTREPID II. Psychological Medicine, Cambridge University Press.

NBC News (2024). Teens who use marijuana are more likely to suffer psychotic disorders, study finds.

Nelson, E-U. E. (2025). Contesting Cannabis Legalization in Nigeria: Hidden Narratives of Illicit Farmers and Traders. Sociological Inquiry.

PMC (2024). Association between psychosis and substance use in Kenya: Findings from the NeuroGAP-Psychosis study.

PMC (2024). Cannabis and psychopathology: 2024 Snapshot of a meandering journey.

PMC (2024). Assessing Cannabis Use in People with Psychosis. Cannabis and Cannabinoid Research.

Psychology Today (2024). The Many Risks of Cannabis and High-Dose THC Use.

Rittiphairoj, T. et al. (2025). High-Concentration Delta-9-Tetrahydrocannabinol Cannabis Products and Mental Health Outcomes. Annals of Internal Medicine.

Schoeler, T., Baldwin, J.R., Martin, E. et al. (2024). Assessing rates and predictors of cannabis-associated psychotic symptoms across observational, experimental and medical research. Nature Mental Health, 2, 865–876.

ScienceDaily (2025). Stronger weed, higher risk? Potent THC linked to psychosis and addiction.

Ezeakunne, M.F. & Unterrainer, H-F. (2025). Substance abuse treatment in Nigeria: applying a biopsychosocial-spiritual framework at MACCARCA. Frontiers in Psychology.

Hoch, E., Hall, W. & Feingold, D. (2025). Cannabis use in Europe. European Archives of Psychiatry and Clinical Neuroscience, 275, 277–279.

Young-Wolff, K.C. et al. (2026). Adolescent Cannabis Use and Risk of Psychotic, Bipolar, Depressive, and Anxiety Disorders. JAMA Health Forum, 7(2).

Disclaimer: This article is published for informational and educational purposes only and does not constitute medical, psychiatric, or legal advice. Behavioural Wealth provides case management and international treatment facilitation services; all clinical treatment is delivered by qualified, regulated professionals at accredited facilities. All legal matters should be directed to qualified legal practitioners in the relevant jurisdiction. If you or someone you know is experiencing a psychiatric emergency, please contact local emergency services immediately.