Children with lower intelligence may face a significantly higher risk of developing alcohol problems as adults, according to alarming new research from Swedish scientists. The study, which tracked almost 600,000 18-year-old boys, found that those who performed worse on cognitive tests were considerably more likely to develop a problematic relationship with alcohol in later life.

This groundbreaking research comes at a time when experts have increasingly warned about a ‘quick fix environment’, where young people are growing up addicted to screens with diminishing attention spans, potentially affecting how their cognitive abilities develop during crucial formative years.

The extensive study provides crucial insights into how intelligence levels measured in adolescence may influence vulnerability to alcohol use disorder (AUD) decades later, raising important questions about early intervention and support for young people with cognitive difficulties.

Major Study Reveals Teenage IQ and Alcohol Connection

A comprehensive Swedish study tracked 573,855 males from age 18 years over an average follow-up period of 60.5 years, examining the association between IQ scores at conscription and subsequent alcohol use disorder diagnoses. The results were striking and consistent across multiple analytical approaches.

Young men with low IQ scores (defined as one standard deviation or more below the population mean) showed a 43% higher lifetime risk of developing alcohol use disorder compared to those with medium IQ levels, even after adjusting for factors such as parental substance use disorder, psychiatric conditions, socioeconomic status, and birth year. Conversely, those with high IQ scores demonstrated a 40% reduced risk of alcohol use disorder.

Of the 573,855 participants followed, 37,333 (6.5%) developed alcohol use disorder during the study period. However, when broken down by IQ group, the rates were markedly different:

• Low IQ group: 10.0% developed alcohol use disorder
• Medium IQ group: 6.4% developed alcohol use disorder
• High IQ group: 4.0% developed alcohol use disorder

Understanding Teenage IQ and Alcohol Risk Patterns

The relationship between low IQ and alcohol use disorder isn’t uniform across the intelligence spectrum. The protective or risk effect was most pronounced at the lower end of the IQ distribution, with lower teenage IQ and alcohol problems showing substantially more risk than higher IQ provided protection. Research showed a nonlinear effect, with approximately 30% predicted impact on alcohol use disorder risk for the lowest IQ levels compared to only 6.5% for higher IQ levels.

This suggests a threshold effect where cognitive vulnerabilities may have disproportionate impacts on substance use outcomes. The association remained robust even in within-sibling comparisons, where brothers with low IQ had nearly 40% increased risk for alcohol use disorder compared to their siblings with medium IQ.

The Genetic Connection Between Cognitive Performance and Alcohol Problems

The research employed sophisticated genetic analyses through Mendelian randomisation to understand whether the link between low IQ and alcohol use disorder represents a causal relationship. The results suggested that lower genetic liability for cognitive performance was causally associated with increased alcohol use disorder risk, indicating that the connection isn’t merely coincidental or due to other confounding factors.

In an independent US cohort of 5,424 participants, individuals with the highest cognitive performance polygenic scores had 35% decreased odds of alcohol use disorder compared to those in the lowest group. This validates the findings across different populations and methodologies.

Educational Attainment and the Low IQ Alcohol Use Disorder Link

The study revealed fascinating differences in how this relationship manifests across different societies. In the Swedish cohort, approximately 14% of the effect of IQ on alcohol use disorder risk was mediated through educational attainment. This suggests that part of the reason low IQ increases alcohol use disorder risk is through its impact on educational achievement.

However, the role of education varied considerably depending on national context. In societies with more equitable access to education and healthcare (such as Sweden and Finland), educational attainment may buffer—though not eliminate—the risk for alcohol use disorder associated with lower cognitive performance. In more stratified social systems, by contrast, educational attainment may amplify the vulnerability by exacerbating disparities in access to health services and opportunities.

Why Low IQ May Increase Alcohol Use Disorder Vulnerability

Several mechanisms may explain the connection between low IQ and alcohol use disorder risk:

Reduced Problem-Solving Capacity: Lower cognitive ability may limit adaptive coping strategies during adversity, making substances more appealing as a coping mechanism.

Impaired Decision-Making: Difficulties in evaluating long-term consequences versus short-term rewards may increase susceptibility to substance use initiation and continuation.

Educational and Occupational Challenges: Lower IQ often translates to fewer educational and career opportunities, potentially increasing stress and reducing access to supportive environments.

Co-occurring Conditions: The research found that individuals with low IQ had higher rates of ADHD (1.1% versus 0.3% in high IQ group) and internalising conditions such as depression and anxiety (13.0% versus 6.9% in high IQ group), which are themselves risk factors for alcohol use disorder.

Socioeconomic Disadvantage: Those with low IQ were more likely to experience household crowding during childhood (25.4% versus 10.2% in high IQ group), an indicator of lower socioeconomic status that independently contributes to substance use risk.

Implications for Prevention and Early Intervention

Understanding the connection between low IQ and alcohol use disorder risk has important implications for prevention strategies. Young people demonstrating cognitive difficulties may benefit from:

• Enhanced Educational Support: Targeted academic interventions that help build coping skills and problem-solving abilities alongside traditional learning.
• Early Monitoring: Healthcare providers and educators should be aware that cognitive struggles in adolescence may signal increased vulnerability to substance use problems.
• Family-Based Approaches: Given that parental substance use disorder affected 11.6% of the low IQ group compared to 7.2% of the high IQ group, family-centred prevention programmes addressing multiple risk factors may be particularly effective.
• Strengthened Social Support Systems: Creating accessible pathways to education, employment, and community resources can help buffer risks associated with lower cognitive ability.

The Importance of Context in Low IQ and Alcohol Use Disorder Research

The research demonstrates that the association between cognitive traits and alcohol use disorder is shaped by both genetic liability and the broader sociocultural environment. Across multiple methods and samples, cognitive performance and IQ were associated with alcohol use disorder risk, but the nature of the association varied across contexts.

In the US-based cohort, for example, those with the lowest cognitive performance scores did not have significantly increased risk compared to average, contrasting with the Swedish findings where low IQ conferred substantial risk. This suggests that sociocultural factors such as educational access, healthcare systems, and state support programmes may shape how cognitive traits influence alcohol use disorder risk.

Looking Forward

This extensive research, spanning over 60 years of follow-up data and incorporating cutting-edge genetic analyses, provides compelling evidence that cognitive ability in adolescence represents a meaningful risk factor for alcohol use disorder. With 6.5% of the overall cohort developing alcohol use disorder during follow-up, and rates reaching 10% amongst those with low IQ, the public health implications are considerable.

The findings underscore the importance of considering cognitive development as part of comprehensive approaches to preventing substance use problems. By identifying vulnerable young people early and providing appropriate support, it may be possible to reduce the elevated risk associated with lower cognitive ability.

Importantly, the research demonstrates that individual genetic predispositions do not operate in isolation. The structural conditions of society—including access to education, healthcare, and economic opportunity—play a crucial role in determining whether cognitive vulnerabilities translate into substance use problems.

Source: (WRD News)

Key Takeaways 

• Broad temporal and population spectrum on cannabis use & mental health.
• Cannabis linked to depression, anxiety and suicidal tendencies in studies.
• Early cannabis use in youth leads to mental health issues in adulthood.
• Systematic review and meta-analysis updates cannabis mental health risks evidence.

Abstract: Cannabis is the most widely consumed illicit drug globally. In 2021, 46 % of countries identified cannabis as the predominant substance associated with drug abuse disorders, with 34 % indicating it as the primary cause for seeking treatment. Young individuals represent the largest consumer demographic, experiencing substantial negative health effects. Despite extensive research on its mental health impacts, many aspects remain unclear. This study examines cannabis use among young people including anxiety, depression, and suicidal behavior. Studies involving individuals aged 15–30 were included. Data sources included PubMed, Mendeley, Embase, WOS, CINAHL, and Scopus. After screening 6466 articles, 36 met the inclusion criteria, with 18 included in the meta-analysis. These studies were published between 2013 and 2025. The results indicated that the odds of depression were 51 % higher in young cannabis users (OR = 1.51, 95 %CI = 1.23–1.86), decreasing to 28 % after adjustment (aOR = 1.28, 95 %CI = 1.10–1.50). Anxiety showed a 58 % increase (OR = 1.58, 95 %CI = 1.15–2.15). For suicidal ideation, the increase ranged from 50 % in unadjusted models (OR = 1.50, 95 %CI = 1.05–2.14) to 65 % in adjusted models (aOR = 1.65 95 %CI = 1.40–1.93). Finally, the odds of suicide attempt were 87 % higher (OR = 1.87, 95 %CI = 1.25–2.80), remaining elevated at 80 % after adjustment (aOR = 1.80, 95 %CI = 1.30–2.49).

(Complete Research - Source: Science Direct )

Abstract

This commentary argues the need to prioritize regulation and abstinence-based prevention and recovery as critical services in efforts to maximize the reduction of substance-related harm and the promotion of mental health at a population-level. Treatment and harm reduction for those experiencing mental health and or substance use problems tends to be poorly integrated with regulatory and prevention approaches, which seek to reduce the development of these problems. This commentary examines evidence from Australia to argue the benefits of more deliberate service system integration based on life-course science. Harm reduction programs dominated the substance use prevention field in Australia until 2009 and were associated with high levels of youth substance use. The introduction of abstinence-based prevention programs and policies effectively reduced adolescent substance use and these reductions have flowed to generational reductions in adult substance use. The potential benefits of Australia’s movement to abstinence-based prevention continue to be disrupted by conflicting harm reduction treatment messages. This commentary outlines the argument to maximize substance use intervention effectiveness and mental health promotion by increasing investment in abstinence-based substance use regulation and prevention and then restructuring treatment and recovery services to more deliberately integrate with this emphasis. The benefits of this approach are argued to include reduction of substance use harm and mental health burden.

(Source: International Journal of Mental Health & Addiction)

A new study published by the University of Sydney has revealed that up to one in 28 Australians (3.64 per cent) may live with fetal alcohol spectrum disorder (FASD), a figure that translates to one child in every classroom or two adults on a bus during peak hour.

The research, published in June 2025, identifies fetal alcohol spectrum disorder in Australia as the nation’s leading non-genetic, lifelong developmental disability. Yet despite this prevalence, most Australian psychologists, social workers, speech therapists and occupational therapists have not received training to recognise or support people with the condition, contributing to high rates of underdiagnosis.

The Hidden Disability

Alcohol exposure at any point during pregnancy causes FASD, a lifelong physical brain-based disability. The condition often hides, receives misdiagnosis or goes unnoticed altogether, leaving those affected without crucial support.

People with fetal alcohol spectrum disorder in Australia face unique challenges including difficulties with learning, memory, impulse control, sensory processing and emotional regulation. They are at significantly higher risk of experiencing mental ill health, substance use disorders, physical health problems, school disengagement and involvement with the justice system.

However, with proper diagnosis, appropriate supports and understanding, people with FASD can thrive, according to Sophie Harrington, CEO of the National Organisation for Fetal Alcohol Spectrum Disorders (NOFASD).

Prevention Campaigns Show Results

The Every Moment Matters campaign, funded by the Australian Government and delivered by the Foundation for Alcohol Research and Education (FARE), launched in 2021 with a clear message: no amount of alcohol is safe during pregnancy.

An evaluation report released in 2025 demonstrated the campaign’s effectiveness, with an estimated 16,554 fewer women drinking alcohol whilst pregnant across the reporting period. The initiative targets both the general public and high-risk groups whilst providing essential training to health professionals.

The Strong Born campaign, led by the National Aboriginal Community Controlled Health Organisation (NACCHO), complements this work by providing culturally appropriate information to Aboriginal and Torres Strait Islander peoples.

Updated Guidelines Released

In 2025, the National Health and Medical Research Council approved updated Australian Guidelines for Assessment and Diagnosis of fetal alcohol spectrum disorder in Australia. The guidelines support health professionals in assessing and diagnosing people with FASD, incorporating the latest evidence whilst strengthening the voices of people with lived experience and Aboriginal and Torres Strait Islander people.

The Australian Department of Health and Aged Care has demonstrated commitment to implementing the National FASD Strategic Action Plan. However, significant gaps remain in prevention, diagnosis and care within national alcohol and other drugs strategies.

The Human Cost

Families and adults supported by NOFASD Australia face daily struggles including repeated school suspensions, unmet needs in classrooms and parents who receive unfair judgement for their children’s behaviours. Many report feeling unheard, misunderstood and dismissed by systems that fail to recognise the condition.

“The profound and far-reaching impacts of FASD remain under-recognised,” Harrington notes. “These gaps perpetuate health and disability justice inequalities and systemic disadvantage for individuals and their families.”

With up to one million Australians potentially living with the condition, the scale of unmet need is substantial.

Critical Reforms Needed

Advocates are calling for the Australian Government to continue its commitment to implementing the National FASD Strategic Action Plan in full. Training and strategies for fetal alcohol spectrum disorder in Australia must be embedded across education, social services, out of home care and justice system reforms.

Key recommendations include universal screening for prenatal alcohol exposure at the earliest stages of pregnancy, continued investment in public awareness campaigns and culturally safe education programmes tailored to at-risk communities.

People with lived and living experience of FASD require targeted, FASD-informed advice and navigational support. Crucially, they must be included in decision-making at both organisational and government levels.

Recognition as a Disability

To ensure equity and inclusion, advocates argue that FASD must be included on the Australian Government’s List of Recognised Disabilities. Without formal recognition, inconsistent access to funding, services and individualised supports throughout people’s lives will continue.

“Australia is at a critical point on fetal alcohol spectrum disorder,” Harrington states. “After decades of advocacy from families, clinicians, researchers and organisations, awareness of the hidden disability is higher than ever in 2025. But despite progress, more education, reform and investment are needed to cement lasting change.”

NOFASD Australia has championed these calls for over 25 years. With growing awareness and evidence, the organisation sees a pivotal opportunity and urgent responsibility to act.

“Through education, policy reform and sustained investment, we can prevent harm before it occurs,” Harrington concludes. “Australia must seize this moment to change the trajectory for the up to one million Australians who live with FASD, and to prevent future generations from experiencing this alcohol-related harm.” (Source: FARE)

Mounting scientific evidence continues to challenge the narrative that cannabis is a harmless substance, with alarming new research demonstrating significant THC effects on fertility and embryonic development.

A groundbreaking study conducted by researchers in Canada and Israel has uncovered disturbing links between THC exposure and chromosomal abnormalities in human embryos created through IVF. The findings add to growing concerns about the drug’s impact on reproductive health at a time when cannabis use amongst pregnant women is reportedly increasing.

Chromosomal Chaos

The research team’s analysis revealed that embryos exposed to THC experienced widespread genetic disruption. When comparing treated embryos to controls, scientists identified 89 genes that became overactive and 227 genes that became suppressed—clear evidence of substantial biochemical interference.

Higher THC concentrations proved even more damaging, with 402 genes showing increased activity and 62 displaying reduced function. These dramatic shifts in genetic expression suggest that the cannabis impact on reproduction extends deep into cellular processes critical for healthy development.

Perhaps most concerning, the study documented a 9% increase in aneuploidy—a condition where embryos possess an incorrect number of chromosomes. This abnormality frequently prevents successful conception or leads to developmental problems. The research also found that THC exposure elevated the likelihood of complex aneuploidy, involving the gain or loss of multiple chromosomes simultaneously.

Male Fertility Under Threat

These findings complement well-established research demonstrating THC effects on fertility in men. A comprehensive 2019 systematic review examined chronic cannabis users and found striking correlations between consumption frequency and sperm quality.

Men smoking cannabis 10 or more times weekly showed significantly lower sperm counts compared to those using it 5 to 9 times per week, suggesting a dose-dependent relationship. A Danish study involving 1,215 participants reinforced these conclusions, revealing that weekly cannabis users had 28% lower sperm concentration and 29% lower total sperm count than non-users.

Epigenetic Concerns Mount

This summer, researchers uncovered evidence that cannabis use can permanently alter DNA expression through methylation—the addition of methyl groups to DNA molecules. This process can affect how genes function without changing the underlying genetic code itself, potentially passing consequences to future generations.

The cannabis impact on reproduction now appears to operate through multiple mechanisms, from direct chromosomal damage to epigenetic modifications that may have long-lasting effects.

Vulnerable Populations at Risk

The Wall Street Journal recently highlighted a troubling trend: increasing numbers of pregnant women turning to marijuana to manage pain and anxiety. Ironically, robust scientific data indicates that cannabis actually exacerbates both conditions rather than alleviating them.

This disconnect between perception and reality reflects the success of industry marketing efforts that have positioned cannabis as a natural, safe alternative to conventional treatments. The consequences of this messaging are now becoming apparent, with expectant mothers potentially exposing their developing babies to significant harm.

A Growing Body of Evidence

The latest research on THC effects on fertility represents just one piece of an increasingly worrying puzzle. Scientific studies have now documented cannabis-related harm across multiple organ systems, including the brain, heart, lungs, and the genetic mechanisms that control cellular function.

The cumulative evidence paints a picture starkly different from the “safe and natural” image promoted by commercial interests. For couples planning to conceive, individuals undergoing fertility treatment, and pregnant women, the message from science is becoming unmistakably clear: cannabis poses serious risks to reproductive health and embryonic development.

The Path Forward

As cannabis legalisation expands across various jurisdictions, the importance of evidence-based public health messaging has never been greater. The recent findings regarding the cannabis impact on reproduction underscore the urgent need for comprehensive education about the drug’s genuine risks, particularly for those of reproductive age.

Healthcare providers working with patients considering pregnancy or undergoing fertility treatment must be equipped with current research to offer informed guidance. The romantic notion of cannabis as a benign natural remedy simply cannot withstand scientific scrutiny, especially when the health of future generations hangs in the balance.

The latest study examining THC effects on fertility serves as a stark reminder that what we put into our bodies can have profound consequences—not just for ourselves, but for the children we hope to bring into the world.

Source: The Drug Report