Comparing cannabis with tobacco: those who start taking cannabis young have the greatest problems.
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Age Factors↗
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Comparing cannabis with tobacco: services are needed for acute and chronic effects of cannabis.
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Delivery of Health Care↗
Improving the debate on cannabis. The effects of cannabis on driving are difficult to evaluate.
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Automobile Driving↗
Swiss debate whether to legalise cannabis. Alcohol and tobacco pose far greater danger, say advocates of cannabis legalisation.
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Drug and Narcotic Control↗
[Cannabis. Analysis of the effects of cannabis on the body and nursing practice in detoxification].
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Humans↗
[Perceptions of cannabis effects a qualitative study among adolescents].
The aim of the study was to compare perceptions of cannabis use effects and risks of tolerance effect, withdrawal syndrome, dependence and repercussions on school, social, and familial functioning among adolescent cannabis users and non users. Subjects were 210 adolescents (121 boys, 89 girls; mean age=16.3 1.3) from the department of Pyrénées-Orientales, France. Subjects completed a questionnaire assessing the frequency of cannabis use, the method of using cannabis, and including open-ended questions (What are the different methods of cannabis use? What are their pleasant and unpleasant or negative effects? What are their risks? Do you think that cannabis effects decrease in intensity when you are used to it? When someone is used to cannabis and stop using it (or has no more of it), does she experience craving for cannabis and withdrawal symptoms? What do you think of cannabis use?). Among the subjects, 118 (56.2%) were cannabis users and 92 (43.8%) were non-users. Among users, 27% used cannabis once a Month or less than once a Month, 21%, more than once a Month; 24%, more than once a weeks; 6%, every day; 20%, more than once a day. The methods of using cannabis were joints (76%), bong (40%), pipe (23%), and ingestion (18%). Knowledge of methods of using cannabis was higher in users than non-users: joint (87% vs 64%, p<0.0001), bong (69% vs 21%, p<0.0001), pipe (38% vs 7%, p<0.0001), ingestion (41% vs 13%, p<0.0001). Fifty-four per cent of users reported that cannabis use induces pleasant affects versus 30% of non-users (p=0.0006). They were exhilaration (47% vs 9%), relaxation (40% vs 23%), cheerfulness (21% vs 10%). Twenty-seven percent of users reported that cannabis use reduces negative feelings versus 14% of non-users (p=0.02). To be more open to social relationships was mentioned by 13% of users versus 1% of non-users (p=0.0001). The negative effects that were reported were attention and cognitive impairment (13% of users vs 5% of non users, p=0.05), irritability (8% vs 8%), loss of control (8% vs 8%) and feeling faint (13% vs 6%, p=0.09). Users reported than bong has much quicker and stronger effects than joints. The effects of bong class cannabis as a hard drug. Physical negative effects or risk were reported by 35% of users versus 30% of non-users (p=0.44). Bong users described specific physical risks such as respiratory problems and fainting. No subjects reported the risk of road accidents. Most users and non-users considered that cannabis use causes dependence (60% vs 74%, p=0.03), tolerance (68% vs 60%, p=0.23), and withdrawal symptoms (76% vs 52%, p<0.001). A minority of users and non-users reported that cannabis use causes a deterioration in school functioning (42% vs 20%, p=0.69), in social activities (23% vs 14%, p=0.10) and in family relationships (29% vs 20%, p=0.14). Most of users (56%) had a global positive opinion of cannabis use whereas most non-users (66%) had a global negative opinion of cannabis use. The frequency and methods of use reported in this study compare with the results of a recent study carried out in another town of the south of France. These results suggest that a high proportion of French adolescents are using cannabis and that a high proportion of users utilize bongs. Perception of cannabis effects and risks of tolerance effect, withdrawal syndrome, dependence and repercussions on school, social, and familial functioning differed between users and non-users. Users have more positive beliefs and less negative beliefs about cannabis than non-users. Users reported more frequently pleasant effects and less frequently unpleasant or negative effects, physical risks, risks of dependence, deterioration in school, social, and familial functioning than non-users. However, only a minority of non-users reported negative effects or consequences of cannabis use. None subjects reported a risk of road accident. These results suggest that information on negative effects, risks and repercussions of cannabis use may be a target for prevention intervention.
Accidents, Traffic↗
Arrests and convictions for cannabis related offences in a New Zealand birth cohort.
AIMS: To examine the associations between the use of cannabis and arrest/conviction for cannabis related offences. METHODS: Data on cannabis use and arrests/convictions for cannabis related offences were gathered during the course of a 21-year longitudinal study of a birth cohort of Christchurch (New Zealand) born children (N=983). Information on cannabis use, arrests and convictions was gathered over the period from 16 to 21 years. RESULTS: By the age of 21, over two thirds of the cohort had used cannabis on at least one occasion with 5% using cannabis on more than 400 occasions. Amongst cannabis users, 5.1% had been arrested for a cannabis related offence and 3.6% had been convicted of an offence. There was a strong association between the extent of cannabis use and risks of arrest/conviction: over a quarter of those using cannabis on more than 400 occasions had been arrested or convicted for a cannabis related offence compared with less than 1% of those using cannabis on fewer than ten occasions. Māori, those with a previous arrest record for non cannabis related offences and those reporting involvement in violent/property offending were more likely to be arrested or convicted than other cohort members having the same level of cannabis use; in addition, males were more likely to be convicted than females with the same level of cannabis use. Arrest/conviction for a cannabis related offence did not reduce the use of cannabis: of those arrested/convicted, 95% either increased their use or continued with the same level of cannabis use subsequent to their arrest. CONCLUSIONS: The results of this study reinforce concerns about laws relating to the use and possession of cannabis. The findings show that the law was administered in an inefficient way, the application of the law was biased, and the law was ineffective in reducing cannabis use.
Adolescent↗
Early reactions to cannabis predict later dependence.
CONTEXT: While there is a growing literature on the linkages between early subjective responses to nicotine and alcohol and later risks of nicotine or alcohol dependence, to date there has been no study of this issue in relation to cannabis. OBJECTIVE: To examine the extent to which subjective responses to early (prior to the age of 16 years) cannabis use were associated with subsequent cannabis dependence in a birth cohort studied to the age of 21 years. DESIGN: Data on early (prior to the age of 16 years) subjective reactions to cannabis use and subsequent cannabis dependence were gathered over the course of the Christchurch Health and Development Study, a 21-year longitudinal study of a birth cohort of children born in Christchurch, New Zealand. SETTING: General community sample. PARTICIPANTS: Members of a population-based birth cohort (86.5% white, 11.3% New Zealand Maori, and 2.2% Pacific Island). Main Outcome Measure Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition cannabis dependence (for those aged 16-21 years). RESULTS: Of the cohort, 198 (20%) had used cannabis prior to the age of 16 years. Among this high-risk group, rates of dependence were high with 21.7% meeting DSM-IV criteria for cannabis dependence by the age of 21 years. There were clear tendencies for rates of cannabis dependence to increase with increasing reports of positive responses to early cannabis use: those reporting 5 positive responses had odds of cannabis dependence that were 28.5 (95% confidence interval, 6.3-133.8) times higher than those not reporting positive reactions to cannabis. The association held (odds ratio, 23.4; 95% confidence interval, 4.0-135.9) after control for potentially confounding factors including the extent of use of cannabis prior to age 16 years. The extent of early negative reactions to cannabis was unrelated to later cannabis dependence. CONCLUSIONS: Early subjective responses to cannabis are prognostic of later cannabis dependence. These findings may suggest the presence of genetically mediated individual differences in early responsiveness to cannabis. Clinicians should be aware that young people who report positive reactions to early use of cannabis are at increased risks of later cannabis dependence.
Adolescent↗
[Relations between anxious, depressive and borderline symptomatology and frequency of cannabis use and dependence].
The aims of this paper is to study the relations between anxious, depressive and borderline symptomatology and cannabis use and dependence in adolescents and young adults. A convenient sample of 212 subjects composed of high-school and college students from Toulouse, France (85 boys, 127 girls; mean age=18.3 1.8 Years) completed questionnaires assessing the patterns of cannabis use, age of first use, the symptoms of dependence using a questionnaire derived from the Mini International Neuropsychiatric Interview, and the anxious, depressive and borderline symptomatology using the STAI-YA (State-Trait Anxiety Inventory; Spielberger et al., 1970), the CES-D (Center for Epidemiological Studies-Depression scale; Radloff, 1977) and the BPI (Borderline Personality Inventory; Leichsenring, 1999), respectively; 54% of subjects reported having used cannabis once during the last 6 Months (45.3% of girls and 66.6% of boys, p=0.002). Frequency of use was higher in boys: eg, 61% of boys used cannabis at least almost daily versus 31% of girls (p<0.00001). Age of first use was lower in boys than in girls (14.6 2.6 versus 15.7 2.3, t=- 2.46, p=0.02). Length of use was higher in boys than in girls (3.9 2.2 versus 3 1.6, t=2.2, p=0.03). Among users, near of 64% of boys and 36% of girls met the criteria for cannabis dependence (p=0.003). BPI, CES-D and STAI-YA scores were compared between non-users and users and between non-dependent and dependent users: the only significant differences were that BPI scores were higher in users versus non-users and in dependent users versus non-dependent users; CES-D and STAI-YA scores did not distinguished users from non-users and dependent users from non-dependent users. BPI and CES-D scores were correlated with the length of cannabis use (Pearson r=0.19 and r=0.19, respectively, p<0.05). In a multiple regression analysis predicting the frequency of cannabis use, we entered age, sex, CES-D, STAI-YA and BPI scores. This model accounted for 23% of the variance of the frequency of use (F5,206=14.4, p<0.0001). Sex, age, and BPI scores were significant predictors (b=- 0.31, t=- 5.03, p<0.0001; b=0.29, t=4.87, p<0.0001, b=0.27, t=3.80, p<0.0001, respectively). CES-D scores were a nearly significant predictor (b=- 0.17, t=- 1.96, p=0.051). STAI-YA scores were not a significant predictor (b=0.11, t=1.29, p=0.20). In a multiple regression analysis predicting the dependence scores, we entered age, sex, frequency of use, CES-D, STAI-YA and BPI scores. This model accounted for 41% of the variance of the dependence score (F6,107=12.6, p=0.005). Frequency of use and BPI scores were significant predictors (b=0.51, t=6.12, p<0.0001; b=0.26, t=2.86, p=0.005, respectively). Age, sex, CES-D and STAI-YA scores were not significant predictors (b=- 1.04, t=- 1.32, p=0.19; b=0.008, t=0.09, p=0.92; b=0.16, t=1.53, p=0.12; b=- 0.14, t=- 1.46, p=0.15, respectively). The frequency of use and dependence observed in this study confirm the results obtained in epidemiological studies of use and dependence in France. The high frequency of daily or almost daily users suggests that a high proportion of subjects were "high" while completing the questionnaires. This is a confounding variable now inevitable in epidemiological studies of cannabis use given the high proportion of daily users. The consequence may be that responses to mood questionnaire express both the acute effect of cannabis consumption and the chronic effect that might be different: the acute euphoriant effect of cannabis may mask a chronic depressive symptomatology induced by chronic cannabis consumption. The antidepressant and anti-anxiety acute effect of cannabis may explain that CES-D and STAI-YA scores did not distinguished users from non-users and dependent users from non-dependent users. The correlation between length of use and CES-D scores may reveal the depressant chronic effect of long-term use. The correlation between length of use and BPI scores suggest that long-term cannabis use induces an increase in borderline symptomatology. Results of the regression analyses suggest that the borderline symptomatology is highly linked to frequency of use and cannabis dependence. This may be due to the increase in borderline symptomatology induced by both acute and chronic effects of cannabis. The relation between cannabis use and dependence on one hand and anxious and depressive symptomatology on the other hand may have been obscured by the acute mood effect of cannabis consumption. Borderline symptomatology appeared to be highly linked to cannabis use and dependence in adolescents and young adults. Borderline personality disorder in adolescents is not the only risk factor for cannabis use and dependence in adolescents: borderline symptomatology even at a subclinical level seems to be a higher risk factor than anxious or depressive symptomatology. The frequency of daily or almost daily users may be a confounding variable for the study of relations between anxiety and depressive disorders in adolescents and young adults.
Adolescent↗
Dutch coffee shops and trends in cannabis use.
Conflicting predictions have been made to the influence of decriminalization on cannabis use. Prohibitionists forecast that decriminalization will lead to an increase in consumption of cannabis, while their opponents hypothesise that cannabis use will decline after decriminalization. Most probably cannabis use in the Netherlands so far evolved in two waves, with a first peak around 1970, a low during the late 1970s and early 1980s, and a second peak in the mid-1990s. It is striking that this trend in cannabis use among youth in the Netherlands rather parallels four identified stages in the availability of cannabis. The number of cannabis users peaked when the cannabis was distributed through an underground market (late 1960s and early 1970s). Then the number decreased as house dealers were superseeding the underground market (1970s), and went up again after coffee shops took over the sale of cannabis (1980s), and stabilised or slightly decreased by the end of the 1990s when the number of coffee shops was reduced. Although changes in cannabis policy went along with changes in availability of cannabis and prevalence of cannabis use, it is questionable whether changes in cannabis policy were causally related to trends in cannabis use. Cannabis use also developed in waves in other European countries that did not decriminalize cannabis, as well as in the US. Consequently, trends in cannabis use seem to develop rather independently of cannabis policy.
Adolescent↗
[Cannabis and schizophrenia: demographic and clinical correlates].
UNLABELLED: The high prevalence of psychoactive substance abuse or dependence among schizophrenic patients has now been well established. Mueser et al. stressed the need to assess the abuse of specific classes of substances and analyse the data accordingly. The objective of this study was to compare the socio-demographic correlates and the clinical features in a group of schizophrenic patients with a lifetime cannabis abuse or dependence according to the DSM III-R with a group of schizophrenic patients who had never presented any abuse or dependence. SUBJECTS AND METHODS: The study included 124 subjects with diagnoses of schizophrenia or schizoaffective disorders according to the DSM III-R. Inclusion criteria for participation in the study were age 18 years or older and willingness to provide consent to participate in the study. The inpatients were evaluated when their condition was stabilised. Assessment tools were the psychoactive substance use disorder section of the Composite International Diagnostic Interview (CIDI), the Positive and Negative Syndrome Scale (PANSS), the Global Assessment of Functioning Scale (GAF). Subjects with cannabis abuse or dependence during their lifetime were compared with subjects without abuse or dependence, using chi(2) test for categorical variables and analyses of covariance (ANCOVA) for quantitative variables. RESULTS: Forty-nine subjects (42,6%) presented lifetime abuse or dependence on one or more substances. Since 19 patients with alcohol, stimulant, sedative or opiate abuse or dependence were excluded, the study finally included 96 subjects including a first group of schizophrenic patients with cannabis abuse (n=6) or dependence (n=24) and a second group without any psychoactive substance abuse (n=66). Thirteen (11.3%) patients presented cannabis abuse or dependence within the 6 months prior to the assessment. The mean SD age of onset of cannabis abuse or dependence was 19.6 +/- 3.0 years. Cannabis abuse/dependence preceded the first psychiatric treatment in 70% of the subjects (n=21). 83.3% of the schizophrenic patients with cannabis abuse or dependence were male (n=25) compared to 62.1% in the group without substance abuse (n=41) (chi(2)=4.32, df=1, p=0.04). Schizophrenic patients with cannabis abuse were significantly younger (mean age: 28.9 +/- 6.3 vs 37.0 +/- 12.7, ANCOVA, F=7.2, df=1,96 p=0.009). There was no significant difference between the two groups for marital status, (chi(2)=5.34, df=2, p=0.07), level of education, (chi(2)=0.93, df=2, p=0.62) professional status, (chi(2)=8.7, df=5, p=0.11), on PANSS total score (ANCOVA, F=0.42, df=1,93, p=0.52), GAF score (ANCOVA, F=0.06, df=1,92, p=0.80), mean number of hospitalizations (ANCOVA, F=3.25, df=1,85, p=0.08), mean age of first psychiatric contact (ANCOVA, F=0.74, df=1,93, p=0.39), and neuroleptic dosages (ANCOVA, F=0.03, df=1,90, p=0.87). In contrast, the total duration of hospitalization was significantly longer for the group with cannabis abuse. Patients with cannabis abuse were more likely to have an history of suicide attempts than subjects without substance abuse (chi(2)=11.52, df=1, p=0.0007). DISCUSSION: The prevalence rates for substance abuse and the socio-demographic characteristics of the population of our study are consistent with findings of previous studies. Male gender and age were significantly related to history of cannabis abuse or dependence. Cannabis abuse frequently preceded the onset of psychiatric treatment. However, both schizophrenia and substance abuse tend to develop gradually, with no clear demarcation for the onset of schizophrenia. The absence of any link between the scores for the subscales of the PANSS and cannabis abuse, both in our study and in some retrospective previous studies, is not suggestive of cannabis abuse as a self-medication of positive or negative symptoms of schizophrenia. Self-medication could concern other symptoms, such as cognitive deficits. In addition, the hypothesis of self-medication has especially been suggested in cocaine abuse or dependence. Some limitations to this study can be discussed. First, although the recruitment was systematic and done in a public mental health service, the patients of our study are not necessarily representative of all schizophrenic patients. Secondly, as in any retrospective study, the prevalence of lifetime substance abuse may have been under-estimated. Urinary toxicology tests may have been able to improve the sensitivity of the diagnosis of recent substance abuse, but structured interviews are more appropriate for the diagnosis of lifetime substance abuse in schizophrenic patients than urinary toxicology tests. CONCLUSION: The socio-demographic characteristics of cannabis abuse or dependence in schizophrenia are similar to those found in general population. Cannabis using schizophrenic patients were more likely to be younger and male than non users. The duration of hospitalization was significantly longer for the group with cannabis abuse. Prevalence of suicide attempts in schizophrenia is closely correlated to cannabis abuse.
Adult↗
The THC content of cannabis in Australia: evidence and implications.
OBJECTIVE: To examine evidence on three claims that: 1) the THC content of Australian cannabis plants has increased up to 30 times; 2) problems experienced by cannabis users have increased in Australia in recent years; and 3) an increase in THC content is the most likely explanation of any increase in cannabis-related problems. METHODS: These claims were assessed by examining data: 1) on THC potency in Australia, the United States and New Zealand; 2) on cannabis-related problems; and 3) from the 1998 National Drug Strategy Household Survey on patterns of cannabis use. RESULTS: 1) Published data do not show a 30-fold increase in THC potency of cannabis but show a more modest increase in the US. 2) There is suggestive evidence of an increase in cannabis-related problems among people seeking treatment for alcohol and drug problems, juvenile offenders and young adults with psychosis. 3) There are two other more plausible explanations for these reportedly higher rates of cannabis-related problems among adolescents and young adults: (i) more potent forms of cannabis ('heads') are more widely used; and (ii) cannabis users are initiating cannabis at an earlier age, thereby increasing the prevalence of harmful patterns of use. CONCLUSIONS: There has probably been a modest increase in the THC content of cannabis, but changing patterns of cannabis use have probably made a larger contribution to any increase in rates of cannabis-related problems among young Australian adults. IMPLICATIONS: Better data on the THC content of cannabis, the extent of cannabis-related problems and the ability of users to titrate the dose of cannabis would contribute to more informed debate.
Adolescent↗
Long-term cannabis use: characteristics of users in an Australian rural area.
AIM: To investigate the characteristics and patterns of cannabis and other drug use among long-term cannabis users in an Australian rural area. DESIGN: Cross-sectional survey of a "snowball" sample of long-term cannabis users. SETTING: The North Coast of New South Wales is an area with high levels of cannabis cultivation and use, and many long-term users. PARTICIPANTS: The study involved 268 long-term cannabis users who had regularly used cannabis for at least 10 years. MEASUREMENTS: A structured interview schedule obtained information on: demographics, social circumstances, patterns of cannabis and other drug use, contexts of use, perceptions about cannabis and legal involvement. FINDINGS: The mean age of the sample was 36 years and 59% were made. The median length of regular cannabis use was 19 years. Most (94%) used two or more times a week and 60% used daily, with a median of two joints per day. Two-thirds (67%) used cannabis in social settings and two-thirds grew cannabis for their own use. The most common reasons for using cannabis were for relaxation or relief of tension (61%) and enjoyment or to feel good (27%). The most commonly reported negative effects were feelings of anxiety, paranoia, or depression (21%), tiredness, lack of motivation and low energy (21%) and effects of smoke on the respiratory system (18%). The majority drank alcohol (79%) and over one-third were drinking at hazardous levels. Most were current (64%) or ex-tobacco smokers (24%). One-quarter (25%) had been charged with possession of cannabis, 11% for cultivation and 6% for supply, with non-drug offences low (8%or less). Overall, three-quarters (72%) believed that the benefits of cannabis use outweighed the risks, 21% felt there was an even balance, and 7% said cannabis had done them more harm than good. CONCLUSIONS: Among long-term cannabis users in this Australian rural area, cannabis use was an integral part of everyday life and it was primarily used in social situations for the same reasons that alcohol use is used in the wider community.
Adult↗
Cannabis use for chronic non-cancer pain: results of a prospective survey.
There has been a surge in interest in medicinal cannabis in Canada. We conducted a questionnaire survey to determine the current prevalence of medicinal cannabis use among patients with chronic non-cancer pain, to estimate the dose size and frequency of cannabis use, and to describe the main symptoms for which relief was being sought. Over a 6-week period in mid-2001, 209 chronic non-cancer pain patients were recruited in an anonymous cross-sectional survey. Seventy-two (35%) subjects reported ever having used cannabis. Thirty-two (15%) subjects reported having used cannabis for pain relief (pain users), and 20 (10%) subjects were currently using cannabis for pain relief. Thirty-eight subjects denied using cannabis for pain relief (recreational users). Compared to never users, pain users were significantly younger (P=0.001) and were more likely to be tobacco users (P=0.0001). The largest group of patients using cannabis had pain caused by trauma and/or surgery (51%), and the site of pain was predominantly neck/upper body and myofascial (68% and 65%, respectively). The median duration of pain was similar in both pain users and recreational users (8 vs. 7 years; P=0.7). There was a wide range of amounts and frequency of cannabis use. Of the 32 subjects who used cannabis for pain, 17 (53%) used four puffs or less at each dosing interval, eight (25%) smoked a whole cannabis cigarette (joint) and four (12%) smoked more than one joint. Seven (22%) of these subjects used cannabis more than once daily, five (16%) used it daily, eight (25%) used it weekly and nine (28%) used it rarely. Pain, sleep and mood were most frequently reported as improving with cannabis use, and 'high' and dry mouth were the most commonly reported side effects. We conclude that cannabis use is prevalent among the chronic non-cancer pain population, for a wide range of symptoms, with considerable variability in the amounts used. Discussions between patients and health care providers concerning cannabis use may facilitate education and follow up, and would allow side effects and potential interactions with other medications to be monitored. Clinical trials of cannabis for chronic non-cancer pain are warranted.
Adolescent↗
Patterns of cannabis use among 13-14 year old New Zealanders.
AIMS: The aims of this study were to document the prevalence and frequency of use of cannabis, the sources of supply of cannabis and reactions to cannabis use in a sample of 949 Christchurch born children studied to the age of 15 years. METHOD: Data on cannabis use was collected on the basis of parental and self report at ages 14 and 15 years. RESULTS: By the age of 15 years, 9.8% of this cohort had used cannabis on one or more occasions and 2.2% of the cohort reported using cannabis on more than 10 occasions. Rates of cannabis use amongst boys and girls were identical. Most of those using cannabis had been provided with the drug by same aged or older teenagers and in most cases it was supplied free. In most cases cannabis was used in small informal groups of 2-8 young people. The majority of cannabis users (75.3%) reported positive reactions to cannabis use and many (58%) said that they would use cannabis again. However, just under one third (30.9%) of users reported some adverse reaction to cannabis use including feeling ill, dizzy or frightened. CONCLUSIONS: By the age of 15 years approximately 10% of young people reported using cannabis. This rate of utilisation appears to be supported by the presence of informal peer networks which provide a source of supply and support for young people experimenting with the use of cannabis. It is conjectured that the source of supply for these informal networks reflects a trickle down of the relatively large amounts of cannabis which circulate amongst adolescent and young adult populations.
Adolescent↗
What are the policy implications of the evidence on cannabis and psychosis?
OBJECTIVE: To explore the implications for mental health services, for health education about the risks of cannabis use, and for public policy toward cannabis use of observational evidence that cannabis use is a contributory cause of psychosis. METHOD: Using comparative analyses of similar evidence for the harmful effects of alcohol, tobacco, and amphetamine use, we considered the relation between observational evidence and action on cannabis. We examined arguments on the grounds of public health prudence for discouraging cannabis use by young individuals. With the assumption that the relation may be causal, we considered recommendations for policy in mental health services, health education, and public policy toward cannabis. RESULTS: The observational evidence and biological plausibility of the hypothesis that cannabis is a contributory cause of psychosis is at least as strong as evidence for causal relations between heavy alcohol and amphetamine use and psychosis. On public health grounds, there is a good case for discouraging cannabis use among adolescents and young adults. It remains uncertain how best to discourage use and at whom campaigns to reduce cannabis use should be targeted. CONCLUSIONS: We should discourage young adults seeking treatment in mental health services from using cannabis and inform them of the probable mental health risks of cannabis use, especially of early and frequent use. We must exercise caution in liberalizing cannabis laws in ways that may increase young individuals' access to cannabis, decrease their age of first use, or increase their frequency of cannabis use. We should consider the feasibility of reducing the availability of high-potency cannabis products.
Canada↗
Estimating the dollar value of the illicit market for cannabis in New Zealand.
New data collected on the procurement and purchase of cannabis in the 2001 New Zealand National Drug Survey are used to estimate the dollar value of the illicit market for cannabis as well conduct other economic analyses of the illicit purchase of cannabis in New Zealand. Eighty-four per cent of last-year cannabis users received at least some of their cannabis 'free', 38% 'bought' at least some of their cannabis, while only 8% grew any of their supply. By proportion of the total dollar value of the cannabis market, sales of 'tinnies' (1.5 g) had the biggest share of the market (30%), followed closely by 50 NZ dollars bags (4 g) (29%) and ounces (28 g) (26%). The average price paid per gram of cannabis fell steadily from 20.50 NZ dollars per gram for a joint to 5.63 per gram for a pound (NZ dollars). The distribution of spending on cannabis was positively skewed (average 1313 NZ dollars, median 400 NZ dollars, mode 100, range 5 - 55,200, interquartile range 100 - 1200) (NZ dollars). The bottom 50% of cannabis buyers spent a median amount on cannabis of 100 NZ dollars a year while the top 5% spent a median amount of 7425 a year (NZ dollars). The dollar value of the illicit cannabis market was estimated to be 190 million (131 - 249 million) (NZ dollars). Three limitations are acknowledged with the market estimate calculated: (i) the truncated age range of the survey data (13 - 45 years); (ii) the likely underestimation of heavy cannabis use in household drug surveys; (iii) a degree of 'double-counting' when the same cannabis is bought and sold a number of times.
Adolescent↗
[Results of a standardized survey on the medical use of cannabis products in the German-speaking area].
The plant Cannabis sativa has a long history of medical use in the treatment of pain and spasms, the promotion of sleep, and the suppression of nausea and vomiting. However, in the early 70s cannabis was classified in the Narcotic Acts in countries all over the world as having no therapeutic benefit; therefore, it cannot be prescribed by physicians or dispensed by pharmacists. In the light of this contradictory situation an increasing number of patients practices a self-prescription with cannabis products for relieving a variety of symptoms. An anonymous standardized survey of the medical use of cannabis and cannabis products of patients in Germany, Austria and Switzerland was conducted by the Association for Cannabis as Medicine (Cologne, Germany). During about one year 170 subjects participated in this survey; questionnaires of 128 patients could be included into the evaluation. 68% of these participants were males, 32% females, with a total mean age of 37.5 (+/- 9.6) years. The most frequently mentioned indications for medicinal cannabis use were depression (12.0%), multiple sclerosis (10.8%), HIV-infection (9.0%), migraine (6.6%), asthma (6.0%), back pain (5.4%), hepatitis C (4. 8%), sleeping disorders (4.8%), epilepsy (3.6%), spasticity (3.6%), headache (3.6%), alcoholism (3.0%), glaucoma (3.0%), nausea (3.0%), disk prolapse (2.4%), and spinal cord injury (2.4%). The majority of patients used natural cannabis products such as marihuana, hashish and an alcoholic tincture; in just 5 cases dronabinol (Marinol) was taken by prescription. About half of the 128 participants of the survey (52.4%) had used cannabis as a recreational drug before the onset of their illness. To date 14.3% took cannabis orally, 49.2% by inhalation and in 36.5% of cases both application modes were used. 72.2% of the patients stated the symptoms of their illness to have 'much improved' after cannabis ingestion, 23.4% stated to have 'slightly improved', 4.8% experienced 'no change' and 1.6% described that their symptoms got 'worse'. Being asked for the satisfaction with their therapeutic use of cannabis 60.8% stated to be 'very satisfied', 24.0% 'satisfied', 11.2% 'partly satisfied' and 4.0% were 'not satisfied'. 70.8% experienced no side effects, 26.4% described 'moderate' and 3.3% 'strong' side effects. 84.1% of patients have not felt any need for dose escalation during the last 3 months, 11.0% had to increase their cannabis dose 'moderately' and 4.8% 'strongly' in order to maintain the therapeutic effects. Thus, this survey demonstrates a successful use of cannabis products for the treatment of a multitude of various illnesses and symptoms. This use was usually accompanied only by slight and in general acceptable side effects. Because the patient group responding to this survey is presumably highly selected, no conclusions can be drawn about the quantity of wanted and unwanted effects of the medicinal use of the hemp plant for particular indications.
Adolescent↗