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Previous research suggests recovery from cannabis-related deficits in verbal learning and memory functioning after periods of cannabis abstinence in adolescents. Here, we examine how cannabis cessation affects cognitive performance over 2 weeks of monitored abstinence compared to controls in adolescents and young adults.
Seventy-four participants (35 cannabis users) aged 16–26 ceased all cannabis, alcohol, and other illicit substance consumption for a 2-week period; abstinence was monitored via weekly urinalysis, breath, and sweat patch testing. Starting at baseline, participants completed weekly abbreviated neuropsychological batteries. Measures included tests of attention, inhibition, verbal working memory, and learning. Repeated measures assessed within and between subject effects for time and group status, while controlling for past year alcohol and nicotine use.
Cannabis users showed increased performance compared to controls on sustained attention tasks after 2 weeks of cannabis use.
Deficits in attention, but not verbal learning and memory, recovered after 2 weeks of monitored abstinence. This differs from previous literature, suggesting that other cognitive domains may show signs of recovery after periods of cannabis cessation in adolescents and young adults.
Adolescence characterize frequent psychical crisis which are result of biological development, looking for own identity, changes in family relation and many socio-cultural influences. Many of social, economic, other environmental factors make some changes in adolescent population. The main objective was finding how many adolescents had risk behavior and subsequences oftener sexual intercourse and aggressive behavior.
Research has done in Banjaluka's high schools, involved 202 adolescents age 18 (51 male, 151 female) which are separate in two groups. Adolescents who consumed psychoactive substances were in experimental group and control group involve adolescents who don’t use psychoactive substances. In research used risk behavior questionnaire Q-2000 (K.B. Kelly, 2000).
Out of total number of individuals in the study, 35,6% was cigarette smokers, 56,9% consumed alcohol, 20,2% consumed marijuana, and sexual intercourse 21,7% (75% used contraceptive methods). Adolescents which used alcohol oftener had sexual intercourse(27,8%, p= 0,026) than adolescents who don’t drink (13,8%), and 29,5% was aggressive in last year. Similar results was found in groups with marijuana and tobacco. Group which used marijuana 34,1% (p= 0,052) had sexual intercourse than group who don’t smoke cannabis (18,6%) and they were aggressive 41,8%. Group which used tobacco had sexual intercourse 34,7% (p=0,0017) than group nonsmokers (14,6%), and aggressive behavior 30,5%.
Adolescents are prone to abuse of psychoactive substances in developing countries. The consequence is higher risk behavior such as violence and promiscuity. Research will be conducted to develop preventive and educational programs in schools.
To examine the link between symptoms of hyperactivity-inattention and conduct disorder in childhood, and the initiation of tobacco and cannabis use, controlling for other behavioral symptoms, temperament and environmental risk factors.
The sample (N = 1107 participants, aged 4 to 18 years at baseline) was recruited from the population-based longitudinal Gazel Youth study with a follow-up assessment 8 years later. Psychopathology, temperament, environmental variables, and initiation of tobacco and cannabis use were self-reported. Event time analyses were performed to assess the effects of childhood disruptive symptoms on age at first use of tobacco and cannabis.
Proportional hazard models revealed that participants with high levels of childhood symptoms of both hyperactivity-inattention and conduct disorder were at highest risk of early tobacco initiation (in males: hazard ratio [HR] = 2.05; confidence interval [CI]: 1.24–3.38; in females: HR = 2.01; CI: 1.31–3.09), and, in males, of early cannabis initiation (HR = 1.95; CI: 1.04–3.64). Temperament, through activity in both males and females and negative emotionality in females, was also associated to early substance use initiation.
Children who simultaneously have high levels of symptoms of hyperactivity-inattention and conduct disorder are at increased risk for early substance initiation. These associations may guide childhood health professionals to consider the liability for early substance initiation in high-risk groups.
Chronic marijuana use impacts an individual’s mind beyond the period of acute intoxication. Persistent downregulation of cannabinoid receptors in the amygdala, the brain’s reward circuitry and frontal cortex alters mental function in a variety of ways, including emotions, motivation and risk of psychotic illness such as schizophrenia. Gruber used a masked faces protocol to demonstrate chronic marijuana users have decreased activity in the amygdala in response to subliminal affective stimuli. She concluded that heavy marijuana users do not process emotional stimuli in the same way as non-users and this is true even when stimuli are below the level of conscious awareness. The complaints by significant others of their marijuana using partner’s emotional absence is consistent with Gruber’s findings. Individuals prone to aggression exhibit more relationship aggression during irritability caused by withdrawal. Decreased motivation over years of marijuana use is evidenced by diminished activity in the nucleus accumbens reward circuitry in response to non-marijuana stimuli. Acute psychotic episodes occur most frequently with high THC products in edible forms. Epidemiologists repeatedly find higher rates of schizophrenia in marijuana users than non-users, and higher rates of marijuana use in schizophrenics than in healthy populations.
Chronic marijuana use impacts an individual’s mind beyond the period of acute intoxication. Persistent downregulation of cannabinoid receptors in the hippocampus and frontal cortex alters cognition in a variety of ways, including memory, executive functions, risk assessment and impulsivity. Decrements in memory are the most consistent and well documented finding. Sensitive neurocognitive testing demonstrates impaired memory and learning worsen with increasing years of regular marijuana use. Pragmatic effects of reduced memory on daily life are measurable. Use as infrequent as once weekly diminishes memory in adolescents under 16. Higher order cognitive functions, including abstract thinking, planning, set shifting, sustained attention and judgement, are all diminished and persist in adolescents after a month of abstinence. The Dunedin study found cognitive deficits can be permanent with onset of marijuana use in early adolescence. Response inhibition in go/no-go tests is reduced with recruitment of wider areas of cortex than required by non-users and lessened awareness of errors, which reduces the ability to learn from mistakes. Scores on the Iowa Gambling Task are reduced, with a bias toward gains versus losses, which reduces judgment of risk.
The future of marijuana is best seen away from the noise passing for debate that engulfs us and with a thorough understanding of the role our endocannabinoid system plays in brain function. Because the endocannabinoid system is hardwired into reward mechanisms, cannabinoid experiences, whether from THC or endogenous sources, are inherently enjoyable. The question to be explored is what natural behaviors activate our endocannabinoids. Cannabinoid based experience will be valued and sought in the future just as endorphin experiences are today and exercise, meditation and other behaviors will be developed and encouraged both for pleasure and homeostatic balancing of brain chemistry. Science will see marijuana as the provenance of vital neurophysiological discoveries. Without marijuana research we might still have no knowledge of our endocannabinoid system. The future will see the development of an array of valuable new medications that stimulate, block and alter our endocannabinoid function. These medications will provide more effective and more narrowly targeted benefits, with fewer side effects, than what marijuana itself can offer. One facet of our relationship to marijuana will not change at all in the future. Experience seekers, especially the young, will continue seeking the intriguing high marijuana produces, and an unfortunate minority will experience addiction.
People often find statistics confusing because anecdotes more effectively tell stories and no one’s direct experience matches the statistical realities. The younger any individual is introduced to any drug the higher the risk of developing dependence. This is especially true for marijuana because it affects neurodevelopment in early adolescence. However, Horwood has shown than the lifetime rate of marijuana dependence does not accurately portray the overall progression of use because the majority of those who ever become dependent discontinue or reduce use sufficiently to no longer meet the DSM criteria for Cannabis Use Disorder (CUD). While 43% of those with onset of marijuana use at 13 years old meet criteria for CUD at some time by age 30, only 15% are dependent during the previous year at 30. The generally accepted rate of CUD for those 12 and older who have ever used marijuana is approximately 9%, compared to a 15% dependence rate for alcohol. The more frequently individuals use marijuana, the more they use on each occasion. The increased rates of marijuana use in Conduct Disorder (CD), Antisocial Personality Disorder (ASPD) and Attention Deficit Hyperactivity Disorder (jsADHD) are discussed.
Research regarding the impact of in utero exposure to marijuana lags behind other areas of interest despite frequent use during pregnancy. The endocannabinoid system is intimately involved with guiding embryonic and fetal axon development and THC has been shown to disrupt microtubules in axonal growth cones, raising concern for potential long term consequences. While no gross birth defects have been associated with prenatal exposure to marijuana, some reduction in birth weight is common. Only three long term studies provide data on the consequences of prenatal exposure: OPPS (Canada), MHPCD (US), and Generation R (Netherlands). Immediate effects on newborns include increased tremors, exaggerated startle, a high-pitched cry and abnormal sleep cycling. Disturbances in memory and verbal development, sustained attention, increased impulsivity and hyperactivity have been documented at various ages from early childhood through the first two decades of life. fMRIs during executive function testing in 18-22-year-olds prenatally exposed to marijuana reveal compensatory recruitment of wider areas of cortex than in controls. Psychological and behavioral problems have also been reported as early as age 6. Both pediatricians (AAP) and obstetricians (ACOG) caution against marijuana use during pregnancy and lactation.
The War on Drugs failed and public opinion is turning against punishing marijuana users in much of the world and within the US. Individual states have become the “laboratories of democracy”, beginning with California’s legalization of medical marijuana in 1996. Latin American countries have become less likely to accept US military assistance to combat drug production. Portugal decriminalized all drugs in 2001 without experiencing increased rates of use and Uruguay legalized marijuana in 2013. In 2016 the UN declared the War on Drugs a failure while calling for “an end to the criminalization and incarceration of users….” In 2011 the California Medical Association (CMA) proposed a regulated legal marijuana market and the California Society of Addiction Medicine (CSAM) proposed a public health framework emphasizing directing tax revenue to services for adolescent substance users. Colorado and Washington state legalized marijuana in 2012, Oregon in 2014 and California in 2016. Implementation of the new industry is currently having difficulty suppressing the previously existing underground market. It still remains to be seen whether a legal marijuana industry that pays for whatever damage its products produce in vulnerable populations can successfully replace an illegal market already in place for years.
After millennia of use as a folk remedy, the National Academies of Sciences, Engineering and Medicine declared there is conclusive or substantial evidence that cannabinoids are effective for the treatment of chronic pain in adults, nausea and vomiting due to chemotherapy and for improving the spasticity of multiple sclerosis. The Academies’ statement contradicts the FDA’s placing marijuana on Schedule I as a dangerous drug with no medical use. Considerable basic research also establishes its potential medical use for bone fractures, osteoporosis, head trauma, stroke, MI, cancer, stress related disease such as PTSD, inflammation, and neurodegenerative disease. Understanding the potential value of cannabinoid-based medications requires understand the function of our natural endocannabinoid system and the unique properties of CBD separate from THC. CBD produces many of marijuana’s medical benefits by altering how cannabinoid receptors respond to endocannabinoids and THC. CBD’s modulation of THC is particularly evident in its reduction of psychotic reactions to THC and possible value in treatment resistant schizophrenia. CBD has a high safety profile, may be useful for anxiety, insomnia, and has FDA approval for severe childhood epilepsy. Unfortunately, intensive marketing has made CBD a fad without rigorous scientific proofs of its often exaggerated benefits.
Most people get information about marijuana from friends, the Internet, newscasts and personal experience – all echo chambers filled with anecdotes, opinions, and little science. Clinicians receive little education about marijuana. From Bud to Brain provides health professionals the science of marijuana needed to offer the public objective and relevant advice about the safe and effective use of marijuana. The need is huge: 1 out of 5 US citizens can buy recreational marijuana legally and over 200 million have access to medical marijuana. Products from the cannabis plant include dried buds (marijuana), resin (hashish) and concentrates (dabs, budder) that can be smoked, vaped or fashioned into edibles. Understanding how THC produces the experience of being high requires understanding the brain’s natural THC-like chemistry and what parts of the brain are impacted by marijuana. Tracing the research discoveries leading to understanding the science of marijuana gives clinicians the scientific context to help patients make wise decisions about its use. The principles of motivational interviewing are reviewed to help clinicians communicate a science-based perspective on marijuana to recreational users, medical patients, adolescents, worried parents and heavy users.
People use marijuana for nonmedical reasons because they like how it affects the brain, and therefore their mind and subjective experience. However, regular use of marijuana alters brain structure and function in ways that persist well beyond the period of acute intoxication. Progressively more powerful research tools are documenting effects in high risk populations with considerably less than daily use. These impacts are generally reversible but may be permanent if they occur during stages of rapid neurodevelopment typical of early adolescence. The volume of gray matter and the number of synaptic connections can be reduced by marijuana use, most importantly in the hippocampus, amygdala, and frontal lobes. Gender differences exist in the impact of marijuana on cortical thickness during adolescence. The functional integrity of white matter interconnecting areas of the brain can also be reduced by chronic marijuana use, which interferes with the endogenous cannabinoid system’s formation of the microtubule skeleton within axons.
Modern marijuana research began in 1964 when Raphael Mechoulam isolated THC, defined its structure and confirmed it is the primary psychoactive chemical in marijuana. After Howlett and Devane demonstrated a cannabinoid receptor in the brain in 1988. Mechoulam isolated anandamide, the first endogenous cannabinoid discovered, 4 years later. The location of CB1 receptors throughout the brain was mapped by Herkenham and their unique presynaptic location discovered by Istvan Katona. The endocannabinoid system functions as a negative feedback homeostatic mechanism regulating the activity of the brain’s other neurotransmitters. Anandamide and 2-AG, the second and more numerous endocannabinoid discovered, are synthesized on demand from arachidonic acid found in cell membranes. Central to all these discoveries is the similarity in molecular structure between anandamide and THC. Researchers had discovered the physical mechanism by which marijuana affects the brain. By matching the f brain areas with high concentrations of cannabinoid receptors with their functions, the specific effect of THC’s mimicry of our natural chemistry began to make sense. The magic of marijuana is in the brain and not in the plant. Marijuana simply drives the endocannabinoid system far from its normal equilibrium.
Adolescence is a distinct and unique phase of life characterized by rapid physical, neurological, psychological and sexual/hormonal development. Frontal lobe maturation consisting of explosive dendritic/synaptic growth and pruning modulates affect emerging from the amygdala, a process called frontalization. Greater powers of abstraction propel adolescents into new perspectives on their world requiring each adolescent to meet several new intertwined psychological challenges, including formation of values and a separate identify beyond simpler childhood notions, becoming autonomous in thought and feeling, choosing a peer group and finding transcendence and meaning in their life. Marijuana not only interferes with the neurodevelopment necessary to meet these psychological developmental tasks, but it also confuses adolescents by seeming to accelerate maturation while actually delaying it. Declaring autonomy and separation by smoking a joint, for example, produces a simulacrum of maturity without requiring the underlying psychological work that is ultimately necessary for launching into successfull adulthood.
Every clinician encounters patients compromised by marijuana, whether fully addicted or not and whether recognized by the individual or not. While adult heavy users usually seek help themselves (often in response to a partner’s pressure or for reasons seemingly unrelated to marijuana use), the parents of heavy adolescent users usually make the initial contact. The Cannabis Youth Treatment Study (CYT) demonstrated that several manualized brief treatment protocols have similar, but limited, success treating adolescents and recommended greater focus on long term monitoring and care. Although CYT established an evidence base for treatment, it was unable to evaluate the skill of individual therapists to engage patients and develop mutual ground for discussion. A motivational interviewing (MI) framework is presented emphasizing engagement and nonjudgmental exploration of patients’ experience and attachment to marijuana. The clinician’s curiosity about each individual’s favorite subjective experiences when high is used to discuss explanations for marijuana’s effects. Scientific information paves the way for introducing the concept of downregulation and potential negative side effects that create cognitive dissonance. The goal is to avoid evoking defensiveness and to help patients struggle with their own internal doubts about marijuana’s ability to help reach their life goals.
Most people who use marijuana enjoy the experience and are going about their lives effectively. But there are others who crash and burn, or at least smolder, especially those in early adolescence. The largest community focused on concern for a loved one’s harmful involvement with alcohol and other drugs is found in Al-Anon Family Groups, which focus on maintaining understanding of the drug-induced neurologically-based salience of marijuana for their loved one and feeling compassion for their addiction. Al-Anon embodies the principle that we are powerless to force an addict to think differently, though we can educate ourselves about addiction, encourage them toward health, present factual information and reflect reality for them. We can learn nonjudgmental ways to respond to their denial, myths and rationalizations. Parental authority also stems from parental integrity – living a life that embodies what you hope children will learn. When adolescents refuse to stop using marijuana despite their parents’ firm insistence, a process of contracting for privileges and consequences can be useful.
The current study examined the relationship between early onset cannabis use (before age 16) and different schizotypy dimensions, and whether gender moderates these associations. Participants were 162 cannabis users, aged 15–24 years, who completed an online assessment examining alcohol and other drug use, psychological distress, and schizotypy. Participants were divided according to whether or not they had started using cannabis before the age of 16 (early onset = 47; later onset = 115) and gender (males = 66; females = 96). The interaction between gender and onset group was significantly associated with the dimension of introvertive anhedonia. Follow-up analyses showed that early onset cannabis use was associated with higher levels of introvertive anhedonia in females only. The current findings suggest that gender is an important moderator in the association between early onset cannabis use, schizotypy, and possibly, psychosis risk.
Current adolescent substance use risk models have inadequately predicted use for African Americans, offering limited knowledge about differential predictability as a function of developmental period. Among a sample of 500 African American youth (ages 11–21), four risk indices (i.e., social risk, attitudinal risk, intrapersonal risk, and racial discrimination risk) were examined in the prediction of alcohol, marijuana, and cigarette initiation during early (ages 11–13), mid (ages 16–18), and late (ages 19–21) adolescence. Results showed that when developmental periods were combined, racial discrimination was the only index that predicted initiation for all three substances. However, when risk models were stratified based on developmental period, variation was found within and across substance types. Results highlight the importance of racial discrimination in understanding substance use initiation among African American youth and the need for tailored interventions based on developmental stage.
This study investigated whether higher maternal choline levels mitigate effects of marijuana on fetal brain development. Choline transported into the amniotic fluid from the mother activates α7-nicotinic acetylcholine receptors on fetal cerebro-cortical inhibitory neurons, whose development is impeded by cannabis blockade of their cannabinoid-1(CB1) receptors.
Marijuana use was assessed during pregnancy from women who later brought their newborns for study. Mothers were informed about choline and other nutrients, but not specifically for marijuana use. Maternal serum choline was measured at 16 weeks gestation.
Marijuana use for the first 10 weeks gestation or more by 15% of mothers decreased newborns' inhibition of evoked potentials to repeated sounds (d’ = 0.55, p < 0.05). This effect was ameliorated if women had higher gestational choline (rs = −0.50, p = 0.011). At 3 months of age, children whose mothers continued marijuana use through their 10th gestational week or more had poorer self-regulation (d’ = −0.79, p < 0.05). This effect was also ameliorated if mothers had higher gestational choline (rs = 0.54, p = 0.013). Maternal choline levels correlated with the children's improved duration of attention, cuddliness, and bonding with parents.
Prenatal marijuana use adversely affects fetal brain development and subsequent behavioral self-regulation, a precursor to later, more serious problems in childhood. Stopping marijuana use before 10 weeks gestational age prevented these effects. Many mothers refuse to cease use because of familiarity with marijuana and belief in its safety. Higher maternal choline mitigates some of marijuana's adverse effects on the fetus.
In nineteenth-century British India, concern regarding large numbers of asylum patients with ‘Indian Hemp Insanity’ led to establishment of the Indian Hemp Drugs Commission. The exotic cannabis plant was widely used in pharmacopeia and a source of government revenue. The Commission was tasked with determining the public health risks of cannabis use, particularly mental illness. This analysis of the Commission report seeks to highlight the status of 1892 cannabis research and compare it with current evidence for medical and recreational cannabis use.
Detailed historiographic review of the Indian Hemp Drugs Commission Report (1892).
In 1892, heavy cannabis use was considered to have been associated with severe mental illness (7.3% of asylum patients; 12.6% of patients with diagnoses). About two-thirds were children and young adults with higher relapse rates. Risk increased with early cannabis use and a family history of mental illness. Cannabis psychosis was found to have a shorter trajectory and better prognosis than other mental illnesses in the asylums. Different cannabis potency and modes of consumption had different effects. Occasional cannabis use was felt to have medicinal benefits for some. Appendices provided symptoms and demographic characteristics of cannabis-induced mental illness.
This important nineteenth-century study observed frequency and dose-related effects of cannabis on mental health, particularly psychotic symptoms in young people with a previous or hereditary risk of mental illness. Pathophysiological observations were consistent with current knowledge. As one of the most systematic and detailed studies of the effects of cannabis of the time it foreshadowed contemporary cannabis issues.