Tag: adolescents

Categories : Mental Health NeurologyTags :

Improper ‘Pruning’ of Brain Connections may Cause Teen Mental Health Disorders

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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.”

Source: University of Cambridge

Categories : Cardiovascular DiseaseTags :

Sedentary Time may Significantly Enlarge Teens’ Hearts

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In adolescents, sedentary time may increase heart size three times more than moderate-to-vigorous physical activity, according to a paper published in the Scandinavian Journal of Medicine & Science in Sports. The British and Finnish researchers explored the associations of sedentary time, light physical activity, and moderate-to-vigorous physical activity with cardiac structure and function.

Recent World Health Organization reports and guidelines note that more than 80% of adolescents across the globe have insufficient physical activity per day. Physical inactivity has been associated with several non-communicable diseases in adults such as cardiovascular diseases, type 2 diabetes, and cancer. In the pediatric population, the majority of movement behaviour studies have focused on the effect of sedentary behaviour and physical activity on cardiometabolic health which includes blood pressure, insulin resistance, blood lipids, and body mass index.

There has been a gap in knowledge on the effect of sedentary time and moderate-to-vigorous physical activity on cardiac structure and function in large adolescent populations due to the scarcity of device-measured movement behaviour and echocardiography assessment in the pediatric population. A higher left ventricular mass, which indicates an enlarged or hypertrophied heart, and a reduced left ventricular function, which indicates decreased heart function, may in combination or independently lead to an increased risk of heart failure, myocardial infarction, stroke, and premature cardiovascular death.

The current study, which used data from the University of Bristol study Children of the 90s (also known as the Avon Longitudinal Study of Parents and Children) included 530 adolescents aged 17 years who had complete measurements of fat mass, muscle mass, glucose, lipids, an inflammation marker, insulin, smoking status, socio-economic status, family history of cardiovascular disease, echocardiographic cardiac function and structure measures, and accelerometer-based measure of sedentary time, light physical activity, and moderate-to-vigorous physical activity.

On average, adolescents spent almost 8 hours/day sedentary and about 49 minutes/day in moderate-to-vigorous physical activity in this new study. It was observed that both sedentary time and moderate-to-vigorous physical activity were associated with higher left ventricular mass. However, the increase in cardiac mass (3.8g/m2.7) associated with sedentary time was three times higher than the cardiac mass increase (1.2g/m2.7) associated with moderate-to-vigorous physical activity. This finding was observed in adolescents irrespective of their obesity status, ie among adolescents who had normal weight and those who were overweight or obese. Importantly, light physical activity was not associated with an increase in cardiac mass but was associated with better cardiac function estimated from left ventricular diastolic function.

“This novel evidence extends our knowledge of the adverse effects of sedentary time on cardiac health. It is known among adults that a 5g/m2 increase in cardiac mass may increase the risk of cardiovascular disease and death by 7–20%. Engaging in moderate-to-vigorous physical activity also slightly enlarged the heart but it seems an acceptable negative side effect considering several other health benefits of moderate-to-vigorous exercise. Hence, public health experts, health policymakers, high school administrators and teachers, paediatricians, and caregivers are encouraged to facilitate adolescent participation in physical activity to enable a healthy heart,” says Andrew Agbaje, a physician and clinical epidemiologist at the University of Eastern Finland.

Source: University of Eastern Finland

Categories : AddictionTags :

Hair Analysis Reveals Double the Number of Adolescent Substance Users

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Far more children and adolescents could be using drugs than admitted to in surveys, according to a new US survey using hair analysis to test for actual drug intake. Published in the peer-reviewed journal American Journal of Drug and Alcohol Abuse, the study of nearly 1300 children aged 9–13 found that, in addition to the 10% self-reporting drug use, an additional 9% had used drugs as determined by hair analysis.

The paper suggests hair analysis far outweighs the accuracy of assessing drug use compared to survey alone, and experts recommend that future research should combine both methods.

“It’s vital that we understand the factors that lead to drug use in teenagers, so that we can design targeted health initiatives to prevent children from being exposed to drugs at a young age,” says study leader Natasha Wade, an assistant professor of psychology at the University of California, San Diego.

Adolescent substance use is a serious public health issue, with 5% of US 8th graders (ages 13–14) reporting cannabis use in the last year. The numbers are even higher for alcohol and nicotine use, with 26% of 8th graders admitting to drinking and 23% to smoking nicotine in the past year. These numbers are worrying, as substance use in adolescence is linked to negative life outcomes, but they may be even higher.

To find out a multidisciplinary team of experts, led by Dr Wade, asked 1390 children whether they had taken drugs in the last year. Hair samples were then also taken so that independent tests could confirm whether recent drug-taking had taken place.

Of the children who were asked if they had taken drugs, 10% agreed that they had. Hair analyses also showed that 10% of adolescents overall tested positive for at least one drug, with 6.1% testing positive for cannabinoids, 1.9% alcohol, 1.9% amphetamines, and 1.7% cocaine.

However, the children that self-reported drug-taking were not the same as those who tested positive through hair samples. In fact, of the 136 cases that self-reported any substance use and 145 whose hair samples were positive for any drug, matches were found for only 23 cases.

Most importantly, hair drug analysis revealed an additional 9% of substance use cases over and above self-report alone, nearly doubling the number of identified substance users to 19%.

“A long-standing issue in substance use research, particularly that relating to children and adolescents, is a reliance on self-reporting despite the known limitations to the methodology. When asked, children may mis-report (unintentionally or intentionally) and say they take drugs when they don’t, or conversely deny taking drugs when they actually do,” Dr Wade adds.

“But rather than scrapping self-reporting of drug use altogether, a more accurate picture of teenage substance use can be gained by measuring both.

“Self-reporting has its own strengths, for instance young people may be more willing to disclose substance use at a low level, but are less likely to when frequent drug-taking patterns emerge.

“Conversely, hair assays are not sensitive enough to detect only one standard drink of alcohol or smoking one cannabis joint. Instead, the method is better at detecting frequent and moderate to heavy drug use.

“Combining both methodologies is therefore vital to accurately determine the levels of substance use in the teenage population.”

Commenting on the findings of their paper, the authors also add however, that it is important to note that there is a chance that some, perhaps even many, of these youth are unaware that they even used a substance, as it could have been given to them by a parent or peer or they may have simply forgotten they had used it.

Source: Taylor & Francis Group

Categories : Mental Health PaediatricsTags :

Boys can Also be at Risk for Eating Disorders

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Depression, young man
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In the public mind, eating disorders are associated mainly with girls from wealthy backgrounds. Now, a new study on twins published in the Journal of Psychopathology and Clinical Science has found that boys living in disadvantaged circumstances are at an increased risk for disordered eating – particularly if they have underlying genetic risk factors.

“This is critical information for health care providers who might not otherwise screen for or recognize disordered eating in this population,” said Megan Mikhail, lead author of the study and Ph.D. candidate in the MSU Clinical Psychology program. “It is also important for the public to recognize that eating disorders can affect everyone, including people who do not fit the historical stereotypes.”

The study from Michigan State University, is the first to look at associations between multiple forms of disadvantage and risk for disordered eating in boys, as well as how disadvantage may interact with biological risks to impact disordered eating in boys.

Using a large population-based sample of male twins from the Michigan State University Twin Registry, the researchers found that boys from more disadvantaged backgrounds reported greater disordered eating symptoms and had earlier activation of genetic influences on disordered eating, which could lead to increased long-term risk.

By using population-based sample, the researchers could avoid overlooking those unable to afford mental health care. They examined factors such as parental income, education and neighbourhood disadvantage to see how those factors related to disordered eating symptoms in the boys. Since all the participants were twins, researchers were also able to study genetic influences on disordered eating.

“This research is particularly relevant following the COVID pandemic when many families experienced financial hardship,” said Kelly Klump, MSU Foundation Professor of Psychology and co-author of the study. “Those financial stressors are putting many young people at risk for an eating disorder, so it’s vital that there be increased screening and access to care for these young people.”

Source: Michigan State University

Categories : Injury & Trauma PaediatricsTags :

After Concussion, Kids Returning to School Sooner is Better

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Contrary to popular belief, rest may not always be the best treatment after a concussion, according to the results of a large multi-centre study published in JAMA Network Open. In fact, an early return to school may be associated with a lower symptom burden after suffering a concussion and, ultimately, faster recovery.

“We know that absence from school can be detrimental to youth in many ways and for many reasons,” says study lead author Christopher Vaughan, PsyD, neuropsychologist at Children’s National Hospital. “The results of this study found that, in general, an earlier return to school after a concussion was associated with better outcomes. This helps us feel reassured that returning to some normal activities after a concussion – like going to school – is ultimately beneficial.”

In this cohort study, data from over 1600 youths aged five to 18 were collected across nine paediatric emergency departments in Canada. Because of the large sample size, many factors associated with greater symptom burden and prolonged recovery were first accounted for through the complex statistical approach used to examine the data. The authors found that an early return to school was associated with a lower symptom burden 14 days post-injury in the 8 to 12 and 13 to 18-year-old age groups.

“Clinicians can now confidently inform families that missing at least some school after a concussion is common, often between 2 and 5 days, with older kids typically missing more school,” Dr Vaughan says. “But the earlier a child can return to school with good symptom management strategies and with appropriate academic supports, the better that we think that their recovery will be.”

The results suggest a possible mechanism of therapeutic benefit to the early return to school. This could be due to:

  • Socialisation (or avoiding the deleterious effects of isolation).
  • Reduced stress from not missing too much school.
  • Maintaining or returning to a normal sleep/wake schedule.
  • Returning to light-to-moderate physical activity sooner (also consistent with previous literature).

Source: Children’s National Hospital 

Categories : Cancer Cardiovascular DiseaseTags :

Study Identifies Risk Factors for CVD among Young Cancer Survivors

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Adolescent and young adult (AYA) cancer survivors are at risk of experiencing treatment-related effects later in life, including cardiac damage. New research published in in CANCER has identified a number of sociodemographic and modifiable risk factors linked to these patients’ risk of developing cardiovascular disease (CVD).

The study by investigators at Duke University and The University of Texas MD Anderson Cancer Center relied on 2009–2018 data from the National Health Interview Survey, which collects information on a broad range of health topics through personal interviews of US households. Responses from 4766 AYA cancer survivors and 47 660 controls (without a history of cancer) were included. 

The risk of CVD was significantly higher in survivors than controls by sex, race/ethnicity, income, education, smoking status, and physical activity.

In the AYA survivor population, male sex, Black race, household income under $50 000 a year, and current or former smoking were all associated with higher odds of CVD. Household income < $50 000 a year disproportionately increased the odds of CVD in survivors compared with controls.  Performing any moderate to vigorous intensity physical activity was associated with lower CVD odds.  

“These results highlight the importance of long-term surveillance of AYAs after cancer treatment to ensure that appropriate screenings are initiated to reduce the risk of CVD and to promote healthy behavioural changes, such as physical activity, which impact long-term CVD outcomes,” said lead author Amy Berkman, MD, of the Duke University School of Medicine. 

Source: Wiley

Categories : Skeletal SystemTags :

Excessive Physical Activity May Impact Teens’ Leg Development

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Doctor shows an X-ray of a foot
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A study published in the Journal of Orthopaedic Research showed that physical activity levels may impact adolescents’ and young adults’ leg alignment during development, as measured by magnetic resonance imaging (MRI) scans.

The study included 57 elite male soccer players compared with 34 male and 34 female controls aged 11–21 years. Outcome measures were the hip knee angle (HKA), medial proximal tibial physeal angle (MPTPhyA), lateral distal femoral physeal angle (LDFPhyA) on full leg length MRI scans, and a physical activity questionnaire score.

Using magnetic resonance imaging scans, physical activity levels were associated with the development of varsus or ‘knock knees’, an abnormal leg alignment, which may represent a physiological adaptation to load where the shin bone meets the knee.

“Our study suggests that abnormal leg alignment, a risk factor for future injury and osteoarthritis, develops in early adolescence due to high activity levels,” said corresponding author Scott Fernquest, DPhil, of the University of Oxford. “Modifying activity levels during this critical period of growth may prevent the development of abnormal leg alignment. We hope our findings lead to further research investigating this possibility.”

Source: Wiley

Categories : General InterestTags :

Half of Teens Trust Fake Health News

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A new study has found that teenagers have a hard time discerning between fake and true health messages. Only 48% of the participants trusted accurate health messages (without editorial elements) more than fake ones. Meanwhile, 41% considered fake and true neutral messages equally trustworthy and 11% considered true neutral health messages less trustworthy than fake health messages. The results highlight a need for better training of teenagers to navigate a world where fake health news is so widespread.

Health mis- and disinformation are a serious public health concern, with an increased spread of fake health news on social media platforms in the last few years. Previous research has shown that online health messages are mostly incomplete and inaccurate and have potentially harmful health information. Fake health news can lead to poor health choices, risk-taking behaviour, and loss of trust in health authorities.

“There has been an explosion of misinformation in the area of health during the COVID pandemic,” said principal investigator Dr Radomír Masaryk, of Comenius University.

While most research on message credibility has focused on adults, Dr Masaryk and his colleagues investigated whether teenagers are similarly equipped.

“As adolescents are frequent users of the internet, we usually expect that they already know how to approach and appraise online information, but the opposite seems to be true” Dr Masaryk said.

The researchers found that 41% of teenagers couldn’t tell the difference between true and fake online medical content. Additionally, poor editing of health messages was not perceived as a sign of low trustworthiness. These latest findings were published in Frontiers in Psychology.

Teenagers and the media

As so-called ‘digital natives’, modern teenagers are the world’s most well-connected group, with 71% of the world’s youth using the internet.

Studies have shown that teens increase their risky behaviour in response to positive portrayals of risky behaviour in the media, such as smoking and drinking. On the other hand, online health information that supports information provided by professionals can lead to healthy lifestyle changes, self-care, and treatment compliance.

Teenagers look at the structural features of a website, such as language and appearance, to evaluate online information. For example, authoritative organisations, trusted brands, or websites with business-like language tend to be more trusted.

Previous research on message trustworthiness with adolescents identified five editorial elements that deduced perceived message credibility: superlatives, clickbait, grammar mistakes, authority appeal, and bold typeface. Based on this prior study, the researchers developed a method to evaluate the effects of manipulation with content and format of health online messages on their trustworthiness in an adolescent sample.

They presented 300 secondary school students (aged between 16 and 19 years old) with seven short messages about the health promoting effects of different fruits and vegetables. The messages had different levels: fake message, true neutral message, and true message with editorial elements (superlatives, clickbait, grammar mistakes, authority appeal, and bold typeface). Participants were then asked to rate the message’s trustworthiness.

The participants were able to discern between overtly fake health messages and health messages whether true or slightly changed with editing elements; 48% of participants trusted the true neutral health messages more than the fake ones. However, 41% of participants considered fake and true neutral messages equally trustworthy and 11% considered true neutral health messages less trustworthy than fake health messages.

Clickbait less likely to work

“Putting trust in messages requires identification of fake versus true content,” said Dr Masaryk.

In the case of health messages that seem plausible and reasonable, teenagers could not tell the difference between true neutral health messages and health messages with editorial elements. Teenagers did not seem to decide on the trustworthiness of a message based on editing cues.

“The only version of a health message that was significantly less trusted compared to a true health message was a message with a clickbait headline,” continued Dr Masaryk.

The results highlight a need for better instruction of teenagers to spot editing cues that give away the quality of a piece of information. The authors suggest focusing on health literacy and media literacy training, and skills such as analytical thinking and scientific reasoning.

“Analytical thinking and scientific reasoning are skills that help distinguish false from true health messages,” Dr Masaryk concluded.

Source: Frontiers

Categories : Substance UseTags :

Surprising Trends among Vaping Teens Reveal Vulnerable Groups

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A study published today in the American Journal of Preventive Medicine used survey data from US high school students to determine how prevalent vaping is in different sexual orientation, race, and ethnicity groups. They found dramatic differences and surprising patterns in vaping rates across these identity markers.

Vaping is on the rise among teens, with half of all US high school students in having tried vaping at least once and a third of these students vaping regularly.

From 2019–2020, the popularity of disposable e-cigarette use among US high school students who currently vaped went up by 1000%, from 2.4% to 26.5%, according to the CDC. Since nicotine in e-cigarettes is highly addictive, and e-cigarette use in teens leads to higher risks of smoking regular cigarettes later in life, researchers wanted to know more about which groups of teens are currently vaping and possible predisposing factors.

The study, which uses survey data of over 38 000 high school students from 2015–2019, fills in a wide gap that exists in e-cigarette studies: research on vaping prevalence among young people at the intersections of more than one minoritised identity.

The study uncovered significant differences in the prevalence of current e-cigarette use between lesbian and heterosexual girls when comparing across racial groups. 

Current e-cigarette use was higher in Black lesbian girls compared to Black heterosexual girls (18.2% vs 7.1%). The rate was also higher in multiracial girls who identify as lesbian compared to multiracial girls who identify as heterosexual (17.9% vs 11.9%). On the other hand, White lesbian girls were found to be at lower risk of current vaping compared to White heterosexual girls (9.1% vs 16.1%).

Among boys, there were no significant interactions between sexual orientation and race or ethnicity in relation to vaping prevalence. 

Previous surveys of gay and lesbian teens suggest that e-cigarette use might be a coping mechanism to deal with the stress of sexual orientation or gender identity-based discrimination or bullying, or a way to bond with others in their social circle, the authors say. However, prior studies have not reported how e-cigarette use prevalence among youth differ at the intersections of sexual orientation, sex, race, and ethnicity. 

One possible reason for finding disparities in e-cigarette use at the intersection of sexual orientation and race among girls, but not boys may be due to higher levels of targeted e-cigarette marketing toward queer women of color, the authors say. 

Prior research has found that when compared to White heterosexual young women (aged 18-24), bisexual Black and Hispanic women reported higher levels of exposure to ads for tobacco products, while there were no substantial differences in exposure to these ads among young adult men.

“For years, the tobacco industry has targeted marketing toward traditionally marginalised groups, whether in clubs, bars, Pride events, or through magazines,” said co-author Andy Tan, associate professor at the Annenberg School for Communication. “Sexual, racial, and ethnic minority youth are more likely to report engaging with online tobacco advertising including e-cigarette ads on social media.”

Source: University of Pennsylvania

Categories : AddictionTags :

Teens Have Triple the Risk of Developing Cannabis Addiction

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Cannabis plants
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Adolescents have more than three times the risk of developing a cannabis addiction than adults, although they may only have the same risk of other mental health problems related to the drug, according to a new study published in the Journal of Psychopharmacology.

The study, led by King’s College London and University College London, found that adolescent cannabis users had the same odds for higher levels of subclinical depression or anxiety than adults cannabis users, nor were they more vulnerable than adult users to cannabis’s associations with psychotic-like symptoms.

These findings build on a separate study by the same team that found adolescents were not more vulnerable to associations between chronic cannabis use and cognitive impairment.

Lead author Dr Will Lawn said: “There is a lot of concern about how the developing teenage brain might be more vulnerable to the long-term effects of cannabis, but we did not find evidence to support this general claim.

“Cannabis addiction is a real issue that teenagers should be aware of, as they appear to be much more vulnerable to it than adults.

“On the other hand, the impact that cannabis use has during adolescence on cognitive performance or on depression and anxiety may be weaker than hypothesised.

“But we also replicated previous work that if someone becomes addicted to cannabis, that may increase the severity of subclinical mental health symptoms. Given adolescents are also at a greater risk of experiencing difficulties with mental health than adults, they should be proactively discouraged from regular cannabis use.”

The findings in both papers come from the CannTeen study, which is comparing the effects of regular cannabis use among adolescents and adults, while also comparing to age-matched controls (non-users of cannabis), a completely novel design.

The study involved 274 participants, including 76 adolescents (aged 16–17) who used cannabis one to seven days per week, alongside similar numbers of adult (aged 26–29) users, and teenage and adult control (comparison) participants, who all reported their cannabis use over the last 12 weeks and responded to mental health questionnaires. The cannabis users in the study, on average, used it four times per week. The adolescent and adult users were also carefully matched on gender, ethnicity, and type and strength of cannabis.

The researchers found that adolescent cannabis users were three and a half times as likely to develop severe ‘cannabis use disorder’ (ie addiction) than adult users, a finding which is in line with previous studies. Cannabis use disorder is defined by symptoms such as cravings; cannabis use contributing to failures in school or work; heightened tolerance; withdrawal; interpersonal problems caused by or exacerbated by cannabis use; or intending to cut back without success. Oof the teenage cannabis users studied, 50% had six or more cannabis use disorder symptoms, qualifying as severe cannabis use disorder.

Among people of any age, previous studies have found that roughly 9–22% of people who try the drug develop cannabis use disorder, and that risk is higher for people who tried it at a younger age, a finding which has now been robustly replicated.

The researchers say that adolescents might be more vulnerable to cannabis addiction because of factors such as increased disruption to relationships with parents and teachers, a hyper-plastic (malleable) brain and developing endocannabinoid system (the part of the nervous system that THC in cannabis acts upon), and an evolving sense of identity and shifting social life.

Adolescent users had greater odds than adult users or adolescent non-users of developing psychotic-like symptoms, but analysis showed that this is because all adolescents, and all cannabis users, are more likely to newly develop psychotic-like symptoms, rather than a different effect of cannabis for teenagers than adults. Thus, there was no interaction between cannabis use and being an adolescent. The researchers say this fits in with prior evidence that cannabis use may increase the likelihood of developing a psychotic disorder such as schizophrenia, but they warn their study did not investigate the risk of clinical psychosis or schizophrenia.

The researchers found that neither teenage nor adult cannabis users were more likely to develop depressive or anxiety symptoms than non-users. Only the adolescents that have severe cannabis use disorder had worse mental health symptoms, but the researchers caution that the small sample size for this group limits their confidence in this finding.

The separate study found that cannabis users were no more likely to have impaired working memory or impulsivity. Cannabis users were more likely to have poor verbal memory (remembering things said to you); this effect was the same in adults and teenagers, so again there was no adolescent vulnerability. However, the researchers caution that cannabis use could impact school performance during a key developmental stage of life.

The researchers caution that these findings were cross-sectional (only looking at one time point), and that longitudinal analyses of how their participants changed over time are ongoing.

Senior author Professor Val Curran (UCL Clinical Psychopharmacology Unit, UCL Psychology & Language Sciences) said: “Our findings suggest that schools should be teaching pupils more about the risk of addiction to cannabis, which has been neglected in drugs education. Becoming addicted to cannabis is a serious problem in itself, but it can also increase the likelihood of other mental health problems. Teenagers should therefore be informed of their greater risk of addiction.”

Source: King’s College London