A registry-based study on cannabis users in Denmark spanning 39 years found that young males were more than twice as likely to develop schizophrenia as young females. The researchers, who published their findings in Psychological Medicine, estimated that about 15% of schizophrenia in this population group is due to cannabis use.
Previous research suggests an increase in schizophrenia population attributable risk fraction (PARF) for cannabis use disorder (CUD). However, sex and age variations in CUD and schizophrenia suggest the importance of examining differences in PARFs in sex and age subgroups.
Moreover, cannabis potency measured by the percentage of delta-9-tetrahydrocannabinol (THC) (main psychoactive component of cannabis) has increased dramatically, eg from 13% in 2006 to 30% in 2016 in Denmark. CUD has also increased markedly – past-year CUD rose significantly from 4.9% in 2014 to 5.9% in 2018 among US 18–25-year-olds.
A growing body of evidence suggests that the relationship between CUD and schizophrenia may differ by sex. Male sex and early heavy or frequent cannabis use are associated with earlier onset of psychosis.
The researchers conducted a nationwide Danish register-based cohort study including all individuals aged 16–49 at some point during 1972–2021, identifying CUD and schizophrenia status.
The researchers examined 6 907 859 individuals, with 45 327 cases of incident schizophrenia during follow-up. Males had slightly higher risk for schizophrenia with CUD (142%) than females (102%). But among 16–20-year-olds, the risk for males (284%) was more than twice that for females (81%). They also found that during the 39-year study period, the annual average increase in PARF for CUD in schizophrenia incidence was 4.8% among males and 3.2% among females. In 2021, among males, this risk fraction was 15%; among females, it was around 4%.
Conclusions
The researchers concluded that “Young males might be particularly susceptible to the effects of cannabis on schizophrenia. At a population level, assuming causality, one-fifth of cases of schizophrenia among young males might be prevented by averting CUD. Results highlight the importance of early detection and treatment of CUD and policy decisions regarding cannabis use and access, particularly for 16–25-year-olds.”
It has been believed speed of information transmitted among regions of the brain stabilised during early adolescence. A study in Nature Neuroscience has instead found that transmission speeds continue to increase into early adulthood, which may explain the emergence of mental health problems over this period. In fact, transmission speeds increase until around age 40, reaching a speed twice that of a 4-year old child.
As mental health problems such as anxiety, depression and bipolar disorders can emerge in late adolescence and early adulthood, a better understanding of brain development may lead to new treatments.
“A fundamental understanding of the developmental trajectory of brain circuitry may help identify sensitive periods of development when doctors could offer therapies to their patients,” says senior author Dora Hermes, PhD, a biomedical engineer at Mayo Clinic.
Called the human connectome, the structural system of neural pathways in the brain or nervous system develops as people age. But how structural changes affect the speed of neuronal signalling has not been well described.
“Just as transit time for a truck would depend on the structure of the road, so does the transmission speed of signals among brain areas depend on the structure of neural pathways,” Dr Hermes explains. “The human connectome matures during development and aging, and can be affected by disease. All these processes may affect the speed of information flow in the brain.” In the study, Dr Hermes and colleagues stimulated pairs of electrodes with a brief electrical pulse to measure the time it took signals to travel among brain regions in 74 research participants between the ages of 4 and 51. The intracranial measurements were done in a small population of patients who had electrodes implanted for epilepsy monitoring at University Medical Center Utrecht, Netherlands.
The response delays in connected brain regions showed that transmission speeds in the human brain increase throughout childhood and even into early adulthood. They plateau around 30 to 40 years of age.
The team’s data indicate that adult transmission speeds were about two times faster compared to those typically found in children. Transmission speeds also were typically faster in 30- or 40-year-old subjects compared to teenagers.
Brain transmission speed is measured in milliseconds, a unit of time equal to one-thousandth of a second. For example, the researchers measured the neuronal speed of a 4-year-old patient at 45 milliseconds for a signal to travel from the frontal to parietal regions of the brain. In a 38-year-old patient, the same pathway was measured at 20 milliseconds. For comparison, the blink of an eye takes about 100 to 400 milliseconds.
The researchers are working to characterise electrical stimulation-driven connectivity in the human brain. One of the next steps is to better understand how transmission speeds change with neurological diseases. They are collaborating with paediatric neurosurgeons and neurologists to understand how diseases change transmission speeds compared to what would be considered within the normal range for a certain age group.
Frequent users of YouTube have higher levels of loneliness, anxiety, and depression according to researchers from the Australian Institute for Suicide Research and Prevention (AISRAP). Published online in MDPI, their study found that the most severely impacted were those under age 29, or who regularly watched content about other people’s lives.
Lead author Dr Luke Balcombe said the development of parasocial relationships between content creators and followers could be cause for concern, however some neutral or positive instances of creators developing closer relationships with their followers also occurred.
“These online ‘relationships’ can fill a gap for people who, for example, have social anxiety, however it can exacerbate their issues when they don’t engage in face-to-face interactions, which are especially important in developmental years,” he said.
“We recommend individuals limit their time on YouTube and seek out other forms of social interaction to combat loneliness and promote positive mental health.”
Dr Balcombe said the amount of time spent on YouTube was often a concern for parents, who struggled to monitor their children’s use of the platform for educational or other purposes.
In the study, two hours per day of YouTube consumption was classed as high frequency use and over five hours a day as saturated use.
In addition, the study determined more needed to be done to prevent suicide-related content being suggested to users by YouTube algorithms.
While ideally, people shouldn’t be able to search for these topics and be exposed to methods, the YouTube algorithm does push recommendations or suggestions based on previous searches, which can send users further down a disturbing ‘rabbit hole’.
Users can report this type of content, but sometimes it may not be reported, or it could be there for a few days or weeks and with the sheer volume of content passing through, it’s almost impossible for YouTube’s algorithms to stop all of it.
If a piece of content is flagged as possibly containing suicide or self-harm topics, YouTube then provides a warning and asks the user if they want to play the video.
“With vulnerable children and adolescents who engage in high frequency use, there could be value in monitoring and intervention through artificial intelligence,” Dr Balcombe said.
“We’ve explored human–computer interaction issues and proposed a concept for an independent-of-YouTube algorithmic recommendation system which will steer users toward verified positive mental health content or promotions.
“YouTube is increasingly used for mental health purposes, mainly for information seeking or sharing and many digital mental health approaches are being tried with varying levels of merit, but with over 10,000 mental health apps currently available, it can be really overwhelming knowing which ones to use, or even which ones to recommend from a practitioner point of view.
“There is a gap for verified mental health or suicide tools based on a mix of AI-based machine learning, risk modelling and suitably qualified human decisions, but by getting mental health and suicide experts together to verify information from AI, digital mental health interventions could be a very promising solution to support increasing unmet mental health needs.”
Scientists have developed two new drug candidates for potentially treating addiction and depression, modelled on the pharmacology of a traditional African psychedelic plant medicine called ibogaine. At very low doses, these new compounds were able to blunt symptoms of both conditions in mice.
The study, published in Cell, took inspiration from ibogaine’s impact on the serotonin transporter (SERT), which is also the target of selective serotonin reuptake inhibitor (SSRI) drugs, such as fluoxetine. A team of scientists from UC San Francisco and Yale and Duke universities virtually screened 200 million molecular structures to find ones that blocked SERT in the same way as ibogaine.
“Some people swear by ibogaine for treating addiction, but it isn’t a very good drug. It has bad side effects, and it’s not approved for use in the US,” said Brian Shoichet, PhD, co-senior author and professor in the UCSF School of Pharmacy. “Our compounds mimic just one of ibogaine’s many pharmacological effects, and still replicate its most desirable effects on behaviour, at least in mice.”
Dozens of scientists from the laboratories of Shoichet, Allan Basbaum, PhD, and Aashish Manglik, MD, PhD, (UCSF); Gary Rudnick, PhD, (Yale); and Bill Wetsel, PhD, (Duke) helped demonstrate the real-world promise of these novel molecules, which were initially identified using Shoichet’s computational docking methods.
Docking involves systematically testing virtual chemical structures for binding with a protein, enabling scientists to identify new drug leads without having to synthesise them in the lab. “This kind of project begins with visualizing what kinds of molecules will fit into a protein, docking the library, optimising and then relying on a team to show the molecules work,” said Isha Singh, PhD, a co-first author of the paper who did the work as a postdoc in Shoichet’s lab. “Now we know there’s a lot of untapped therapeutic potential in targeting SERT.”
Optimising a shaman’s cure
Ibogaine is found in the roots of the iboga plant, which is native to central Africa, and has been used for millennia during shamanistic rituals. In the 19th and 20th centuries, doctors in Europe and the US experimented with its use in treating a variety of ailments, but the drug never gained widespread acceptance and was ultimately made illegal in many countries.
Part of the problem, Shoichet explained, is that ibogaine interferes with many aspects of human biology.
“Ibogaine binds to hERG, which can cause heart arrhythmias, and from a scientific standpoint, it’s a ‘dirty’ drug, binding to lots of targets beyond SERT,” Shoichet said. “Before this experiment, we didn’t even know if the benefits of ibogaine came from its binding to SERT.”
Shoichet, who has used docking on brain receptors to identify drugs to treat depression and pain, became interested in SERT and ibogaine after Rudnick, an expert on SERT at Yale, spent a sabbatical in his lab. Singh picked up the project in 2018, hoping to turn the buzz around ibogaine into a better understanding of SERT.
It was the Shoichet lab’s first docking experiment on a transporter – a protein that moves molecules into and out of cells – rather than a receptor. One round of docking whittled the virtual library from 200 million to just 49 molecules, 36 of which could be synthesised. Rudnick’s lab tested them and found that 13 inhibited SERT.
The team then held virtual-reality-guided “docking parties,” to help Singh prioritise five molecules for optimization. The two most potent SERT inhibitors were shared with Basbaum and Wetsel’s teams for rigorous testing on animal models of addiction, depression and anxiety.
“All of a sudden, they popped – that’s when these drugs looked a lot more potent than even paroxetine [Paxil],” Shoichet said.
Manglik, an expert with cryo-electron microscopy (cryo-EM), confirmed that one of the two drugs, dubbed ‘8090,’ fit into SERT at the atomic level in a way that closely resembled Singh and Shoichet’s computational predictions. The drugs inhibited SERT in a similar way to ibogaine, but unlike the psychedelic, their effect was potent and selective, with no spillover impacts on a panel of hundreds of other receptors and transporters.
“With this sort of potency, we hope to have a better therapeutic window without side effects,” Basbaum said. “Dropping the dose almost 200-fold could make a big difference for patients.”
Researchers have released positive topline data from a trial evaluating microdoses of lysergide, commonly known as LSD, in the treatment of major depressive disorder (MDD). The investigator-initiated Phase 2 trial was led by Prof Matthias Liechti and Dr Felix Mueller at University Hospital Basel (UHB) and the University Hospital of Psychiatry, and supported by Mindmed.
Lysergide is a potent semi-synthetic hallucinogen that has gained some notoriety as an illicit drug but in recent years has been investigated as a treatment for MDD, alongside other psychedelic drugs. The new trial compared lower and higher doses of lysergide, though at still small doses. Previous research also showed benefits in treating anxiety.
The topline data demonstrated significant, rapid, durable and beneficial effects of lysergide and its potential to mitigate symptoms of MDD. The high dose lysergide regimen in which 28 patients received 100µg at their first dosing day and 200µg at their second dosing day (separated by four weeks) resulted in statistically and clinically significant improvements on the primary endpoint, which was the change in clinician-rated depressive scores 6 weeks after the first administration as compared to control (whether or not the patient received a second administration). The 27 members of the control group received a lower dose regimen of 25µg on both treatment days. Both groups had improvements compared to the placebo group. Data from the secondary endpoints were also encouraging, and the investigational drug was generally well-tolerated, as indicated by reported adverse events, changes in vital signs and laboratory values.
“We continue to be encouraged by the positive results being generated on the clinical activity of lysergide by our collaborators at UHB,” said Robert Barrow, Chief Executive Officer and Director of MindMed, the company behind the trial. “The statistically and clinically significant improvements observed in this study reinforce preliminary findings that have shown the clinical potential of lysergide in anxiety, depression and other brain health disorders. These positive findings are particularly relevant to our MM-120 program in generalized anxiety disorder, given the high degree of comorbidity of GAD and MDD. I would like to congratulate and thank our collaborators at UHB for once again generating high quality clinical data that continue to support the progression of our pipeline.”
Prof. Matthias Liechti, co-primary investigator of the trial, commented, “Historical studies of lysergide in MDD demonstrated rapid, robust and sustained improvement in depressive symptoms. We also observed improvement in depressive symptoms in patients with anxiety disorders in another of our recently published trials. We believed it was necessary to confirm the historical studies with ones using modern methods. Hence, we designed this randomised-controlled trial to assess the benefits of lysergide treatment in MDD. Importantly, an active small dose of lysergide was used as the control. We are extremely encouraged by the results we presented today, which demonstrate the strong, rapid and enduring improvements of this compound in patients suffering from MDD. We look forward to publishing the completed results in a peer-reviewed journal along with additional analyses. Our lab will continue investigating the therapeutic potential of lysergide and other psychedelics.”
MindMed supports the UHB Liechti Lab in conducting investigator-initiated trials for lysergide and other novel therapies and has exclusive access and rights to the data generated by these studies.
South Africa’s long-awaited new National Mental Health Policy Framework and Strategic Plan 2023 – 2030 has been published. The policy framework was presented at the SA mental health conference this week. PHOTO: DOH/Twitter
But even though there has been a gap from 2020 to 2023, speaking to Spotlight at the conference, Minister of Health Dr Joe Phaahla said that it doesn’t mean there was a gap in terms of updating. “Every either three or five years, we revise the policy. So, it is not that there has been a gap. There has been a policy, which has been guiding,” he said.
“But as things change, and in each cycle of the strategy and planning, we have a particular timeframe so that we can evaluate. And so now we have evaluated, and that’s why we are adding [additional things], as we learned from the previous implementation.”
Phaahla said that gaps in the country’s mental health services are not because of a lack of policy and plans but due to implementation issues and sometimes the shortage of resources and psychiatrists.
“If you look at the area of psychiatrists, it is just the two-tier system of our health service, which makes it very difficult because what psychiatrists can earn providing the services to more of the insured patients – it is something we can’t really match with the public sector salaries generally,” he said. Phaahla said that psychiatrists, who mostly work in the private sector, were typically trained at public-sector teaching hospitals. “But once they’re qualified, they stay for one year or so, then they are attracted by better income,” he told Spotlight.
According to Phaahla, to deal with the shortage of psychiatrists in provinces such as the Northern Cape where there are only three psychiatrists, the department plans to contract psychiatrists from other provinces. “We can have part-time psychiatrists, maybe take some from Gauteng where the majority are and in Western Cape and contract them to provide services in Northern Cape. Even if it’s on a weekly rotation,” he said.
Concerns over delays
While several mental health experts have welcomed the new policy framework and agree with Phaahla about the importance of implementation, they are not happy about the delays.
“We’re now sitting in 2023, three years late,” said Cassey Chambers of the South African Depression and Anxiety Group (SADAG). What that means, she said, is that civil society did not have a working document with which to engage government at provincial or district level.
Bharti Patel of the South African Mental Health Federation expressed similar concerns. “As the Federation for mental health, we are disappointed that it has taken this long for the policy to be reviewed, given the fact that the initial policy was launched in 2013,” said Patel.
“We had a crisis during that period from 2013 to 2020. We have witnessed mental healthcare users losing their lives during Life Esidimeni. The [Health] ombud report, the South African Human Rights Commission Report, have all given recommendations,” Patel said. Patel argues that those recommendations should have informed policy and implementation more quickly.
Implementation problems
Chambers described the previous strategic policy framework as a “very good document”. Then, she said, the problem came in the implementation. “And I think perhaps this is [why there was a] delay in having an updated document that is now running from 2023 to 2030. It is because the document was good, the policy was good. However, how it was implemented was not happening,” she said.
Speaking to Spotlight, Professor Crick Lund, Co-Director, of the Centre for Global Mental Health at King’s College London, explained that there are a number of factors that create implementation challenges. “The one is ignorance on the part of senior decision-makers about mental health, ignorance about the scale of the problem, and ignorance about the fact that something can be done about it,” he said.
According to Lund, the new policy framework has stronger implementation monitoring mechanisms and implementation can be tracked in a much clearer way over time.
For the new policy framework to work better than the previous one, Lund believes there is a need to create greater public awareness about mental health and about the mental health policy. He says, “We need to get all the sectors involved working together – the Department of Health, Education, Social Development, the criminal justice system, and also the NGO sector.”
Along similar lines, Patel stressed the importance of getting more government departments involved. “While the policy is developed at the national level, the National Department of Health is responsible for training the provinces and not only the Department of Health; they need to train all government departments within the province who have bought this policy,” she said. “You can’t have the Department of Health alone implement a policy. This is a policy that requires inter-sectoral collaboration so that different departments can also put budgets towards implementation.”
Lund said that there is a lot of common agreement on what the priorities are and a lot of energy going forward. “So I’m hopeful that we can move things forward.”
Budgets and human resources
While there seems to be consensus on the need for more training and getting wider buy-in, there is also a shared awareness that successful implementation will depend on the availability of sufficient funds and human resources.
“We need to see structured action plans in the provinces with budgets allocated so that we can hold the government departments accountable,” said Patel.
Chambers agrees that in order to get implementation of the new policy framework right, we will have to get the budgets right. “You need to allocate a budget in order to help with the implementation plan, especially knowing that our previous policy framework was not implemented. So, we have to overcompensate for that now, which is concerning because this year, the health budget has been reduced. Therefore, meaning that the national mental health budget has been reduced,” she said.
According to the new policy framework, the case for investing in mental health is strong. It states that at a societal level, lost income associated with mental illness far exceeds public sector expenditure on mental healthcare – in other words, it costs South Africa more to not treat mental illness than to treat it. The impact of mental illnesses such as depression and anxiety has been estimated to cost the economy more than US$3.6 billion (R61.2 billion) in lost earnings per year. Certain conditions such as perinatal depression and anxiety have lifelong cost consequences. For example, it is estimated that the lifetime costs of perinatal depression and anxiety in South Africa amount to US$2.8 billion (R47.6 billion) per annual cohort of births.
Chambers also stressed that we are facing shortages of human resources and appropriate facilities. “We don’t have the human resources or the capacity to fulfil that implementation plan and that’s a worry and a concern,” she said.
NHI and provincial plans
According to the new policy framework, mental health will be financed according to the principles adopted for all health financing in South Africa, and people will be protected from the catastrophic financial consequences of mental ill-health.
According to the policy framework, in the financing of the National Health Insurance (NHI) system, mental health services will be given parity with other health conditions, in proportion to the burden of disease and evidence for cost-effective interventions. NHI will specifically include packages of care for mental health, in line with the evidence for the most cost-effective interventions. The policy framework states that private medical aid schemes should be required to provide similar parity between mental health and other health conditions.
“Budget will be allocated to meet targets set for the implementation of the policy and regular discussions will be held with provinces to discuss strategies and monitor progress with implementation. At provincial level, mental health budgets will be reviewed annually to align mental health with national priorities, for each of the areas for action in 2023 and annually thereafter,” the policy framework reads.
The policy also says that all provinces will develop provincial strategic plans for mental health, in keeping with national policy, which outlines specific strategies, targets, timelines, budgets, and indicators in 2023 and annually thereafter, informed by specific unique local challenges.
Problems with the brain’s ability to ‘prune’ itself of unnecessary connections may underlie a wide range of mental health disorders that begin during adolescence, according to research published in Nature Medicine.
The findings, from an international collaboration, led by researchers in the UK, China and Germany, may help explain why people are often affected by more than one mental health disorder, and may in future help identify those at greatest risk.
One in seven adolescents (aged 10-19 years old) worldwide experiences mental health disorders, according to the World Health Organization (WHO). Depression, anxiety and behavioural disorders, such as attention deficit hyperactivity disorder (ADHD), are among the leading causes of illness and disability among young people, and adolescents will commonly have more than one mental health disorder.
Many mental health problems emerge during adolescence, such as depression and anxiety, which manifest as ‘internalising’ symptoms, including low mood and worrying. Other conditions such as attention deficit hyperactivity disorder (ADHD) manifest as ‘externalising’ symptoms, such as impulsive behaviour.
Professor Barbara Sahakian from the Department of Psychiatry at the University of Cambridge said: “Young people often experience multiple mental health disorders, beginning in adolescence and continuing – and often transforming – into adult life. This suggests that there’s a common brain mechanism that could explain the onset of these mental health disorders during this critical time of brain development.”
In the study, the researchers say they have identified a characteristic pattern of brain activity among these adolescents, which they have termed the ‘neuropsychopathological factor’, or NP factor for short.
The team examined data from 1,750 adolescents, aged 14 years, from the IMAGEN cohort, a European research project examining how biological, psychological, and environmental factors during adolescence may influence brain development and mental health. In particular, they examined imaging data from brain scans taken while participants took part in cognitive tasks, looking for patterns of brain connectivity – in other words, how different regions of the brain communicate with each other.
Adolescents who experienced mental health problems – regardless of whether their disorder was one of internalising or externalising symptoms, or whether they experienced multiple disorders – showed similar patterns of brain activity. These patterns – the NP factor – were largely apparent in the frontal lobes, the area at the front of the brain responsible for executive function which, among other functions, controls flexible thinking, self-control and emotional behaviour.
The researchers confirmed their findings by replicating them in 1799 participants from the ABCD Study in the USA, a long-term study of brain development and child health, and by studying patients who had received psychiatric diagnoses.
When the team looked at genetic data from the IMAGEN cohort, they found that the NP factor was strongest in individuals who carried a particular variant of the gene IGSF11 that has been previously associated with multiple mental health disorders. This gene is known to play an important role in synaptic pruning, a process whereby unnecessary brain connections – synapses – are discarded. Problems with pruning may particularly affect the frontal lobes, since these regions are the last brain areas to complete development in adolescents and young adults.
Dr Tianye Jia from the Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China and the Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK said: “As we grow up, our brains make more and more connections. This is a normal part of our development. But too many connections risk making the brain inefficient. Synaptic pruning helps ensure that brain activity doesn’t get drowned out in ‘white noise’.
“Our research suggests that when this important pruning process is disrupted, it affects how brain regions talk to each other. As this impact is seen most in the frontal lobes, this then has implications for mental health.”
The researchers say that the discovery of the NP factor could help identify those young people at greatest risk of compounding mental health problems.
Professor Jianfeng Feng from Fudan University in Shanghai, China, and the University of Warwick, UK, said: “We know that many mental health disorders begin in adolescence and that individuals who develop one disorder are at increased risk of developing other disorders, too. By examining brain activity and looking for this NP factor, we might be able to detect those at greatest risk sooner, offering us more opportunity to intervene and reduce this risk.”
Analysis of US poison centre data has shown that suspected suicidal cannabis exposures have increased 17% annually, over a period of 12 years. According to the study published in the journal JAMA Network Open, more than 92%, involved other substances in addition to cannabis, and the data cannot show a direct causal link between cannabis and suicide attempts.
Still, the findings are cause for concern, the researchers said, especially since the increase was more pronounced among children and women during and after the pandemic.
“This study adds to already ample evidence that cannabis use, particularly by younger people, has significant implications for mental health,” said study co-author Tracy Klein, a WSU associate professor of nursing. “We don’t have evidence that cannabis alone was the primary driver of a suicide attempt, but we do know that cannabis can worsen certain mental health conditions and increase impulsivity.”
The researchers found 18,698 cases of intentional, suspected suicide cannabis exposures reported to U.S. poison centers from 2009 to 2021. Of these cases, 9.6% resulted in death or major outcomes such as permeant disability. The researchers noted that while more of these exposures involved younger people, severe consequences occurred more often among people 65 and older.
U.S. poison centers take calls 24-hours a day from households and healthcare facilities to provide toxicology expertise in suspected poisoning cases. They also investigate the causes, often following up with patients and doctors to determine if patients took substances intentionally or not.
It is well known that accidental cannabis poisonings have been increasing since many states legalized cannabis. Some policies can help prevent these unintentional cases, Klein said, such as packaging guidelines so edible cannabis products are not mistaken for candy.
Intentional cannabis poisonings, on the other hand, have not been well studied, which is one of the reasons the researchers undertook this analysis, and their findings point to the need for more mental health services.
“We have a significant shortage of mental health and primary care providers in the United States,” Klein said. “We know that mental health needs not only changed but became even more acute during the COVID-19 emergency. Cannabis is one part of that.”
Other research has shown that cannabis use is associated with depression and anxiety in youth and that it may interfere with brain development as well. Recent studies have also suggested a link between suicidal ideation and cannabis use in young people. Given this evidence, it is especially important to limit youth access to cannabis, said Janessa Graves, first author and a WSU nursing associate professor.
“Children and adolescents shouldn’t be able to purchase or access cannabis,” Graves said. “We also need to educate kids and parents around the risks of cannabis. I think many people just aren’t aware the impacts cannabis can have on brain development, and on behavioural and mental health, especially in adolescents and young adults.”
Researchers have identified a strong association between prevalence of prescription stimulant therapy for attention-deficit/hyperactivity disorder (ADHD) and rates of prescription stimulant misuse by students in US middle and high schools. Published in JAMA Network Open, the study highlights the need for assessments and education in schools and communities to prevent medication-sharing among teens. This is especially important considering non-medical use of prescription stimulants among teens remains more prevalent [PDF] than misuse of any other prescription drug, including opioids and benzodiazepines.
The study used data collected between 2005 and 2020 by the Monitoring the Future (MTF) study. MTF is a large, multicohort survey of legal and illicit drug use among American adolescents in eighth, 10th, and 12th grade.
“The drug supply has rapidly changed, and what looks like medications – bought online or shared among friends or family members – can contain fentanyl or other potent illicit substances that can result in overdoses. It’s important to raise awareness of these new risks for teens,” said NIDA Director Nora Volkow, MD. “It’s also essential to provide the necessary resources and education to prevent misuse and support teens during this critical period in their lives when they encounter unique experiences and new stressors.”
Stimulant therapy is an evidence-based treatment for ADHD, but it can also be harmful if used without prescription or guidance from clinicians. Prolonged stimulant misuse can lead to several detrimental health effects including cardiovascular conditions, depressed mood, overdoses, psychosis, anxiety, seizures, and stimulant use disorder.
Previous studies have shown that more than half of adolescents who misuse prescription stimulants get the medication for free from friends or relatives. While diagnoses of ADHD and prescribing of stimulant therapy for ADHD have increased significantly in the United States over the past 20 years, few studies have looked at the relationship between stimulant therapy and prescription stimulant misuse in schools. This is the first large, national study to examine prevalence of prescription stimulant misuse and factors correlating with prevalence among students in eighth, 10th, and 12th grade across the U.S.
Researchers at the University of Michigan examined both school- and individual-level characteristics associated with prescription stimulant misuse. Across 231 141 student participants surveyed at 3,284 secondary schools, the school-level prevalence of nonmedical use varied from 0% to over 25% of students. Schools with a greater number of students (12% or higher) reporting prescription stimulant therapy for ADHD tended to have the highest percentages of their student body reporting prescription stimulant misuse (8% of total student body). By comparison, schools with fewer students (0 to 6% of student body) reporting stimulant therapy for ADHD were associated with lower rates of prescription stimulant misuse (4 to 5% of student body).
Other features of schools that were associated with increased rates of misuse included having a higher proportion of parents with higher levels of education, being located in non-Northeastern regions of the US and in suburban areas, having a higher proportion of non-Hispanic white students, and showing “medium-level” (10-19% of total student body) binge drinking. However, the association between school prevalence of stimulant therapy for ADHD and prescription stimulant misuse remained strong when accounting for prevalence of other types of substance use and numerous other individual- and school-level sociodemographics.
Recent research from this team expands on the associations found in this study, including a study that suggested teens with a history of taking both stimulant or non-stimulant medications for ADHD are at high risk for prescription stimulant misuse, as well as cocaine and methamphetamine use. The researchers note that it is important to interpret these results as associations, not causations, and that the primary goal of these kinds of studies is to inform effective preventative and support [PDF] strategies for teens.
“The key takeaway here is not that we need to lessen prescribing of stimulants for students who need them, but that we need better ways to store, monitor, and screen for stimulant access and use among youth to prevent misuse,” said study author Sean Esteban McCabe, PhD. “There’s variation in stimulant misuse across different schools, so it’s important to assess schools and implement personalised interventions that work best for each school. It’s also critical to treat and educate teens on prescription stimulants as the medications they are intended to be and limit their availability as drugs of misuse.”
Depression is widely reported to be more common in women than in men, with women twice as likely to receive a diagnosis than men. A new study published in Nature has found that there are differences between male and female genes and how they relate to depression.
In a genome-wide association(GWA} study, the McGill University researchers analysed the genomes of more than 270 000 individuals. They found that sex-specific prediction methods were more accurate in forecasting an individual’s genetic risk of developing depression than prediction methods that did not specify sex. The researchers found 11 areas of DNA that were linked to depression in females, and only one area in males.
In both males and females, genetic correlations were significant between the broad depression GWA and other psychopathologies; however, correlations with educational attainment and metabolic features including body fat, waist circumference, waist-to-hip ratio and triglycerides were significant only in females. Gene-based analysis showed 147 genes significantly associated with broad depression in the total sample, 64 in the females and 53 in the males.
Despite the biological processes involved in depression being similar in males and females, researchers found that different genes were involved for each sex. This information can be useful to identify future sex-specific treatments for depression. “This is the first study to describe sex-specific genetic variants associated with depression, which is a very prevalent disease in both males and females. These findings are important to inform the development of specific therapies that will benefit both men and women while accounting for their differences,” says Dr Patricia Pelufo Silveira, lead author and Associate Professor in the Department of Psychiatry. “In the clinic, the presentation of depression is very different for men and women, as well as their response to treatment, but we have very little understanding of why this happens at the moment.”
