Marijuana abuse

With regard to THC (Δ 9 -tetrahydrocannabinol), the main psychoactive constituent identified in the plant Cannabis sativa L, several facts are indisputable. Cannabis remains the most commonly used drug in the UK among those who reported driving under the influence of illegal drugs in the previous 12 months. There is a significant dose-related decrement in driving performance following cannabis use; raised blood THC concentrations are significantly associated with increased traffic crash and death risk. When cannabis and alcohol are detected together, there is a greater risk to road safety than when either drug is used alone. Patterns of use are important when interpreting blood concentration data: Smoking infrequently a single cannabis cigarette leads to peak plasma THC concentrations (21-267 μg/L) causing acute intoxication. In habitual, daily users, plasma THC concentrations range from 1.0 to 11.0 μg/L and are maintained by sequestration of the drug from the tissues. These facts undoubtedly make setting thresholds for drug-driving legislation difficult but there is clearly a case for cannabis. Determining minimum blood THC concentrations at which a driver becomes sufficiently impaired to be unable to safely drive a vehicle is of particular concern given the increasing medicinal use of the drug. Internationally legislation for driving under the influence of drugs (DUID) is based on either a proof of impairment or a per se approach. For the latter this can be either zerotolerance or based on concentration limits such as those used for alcohol. The different approaches are considered against current scientific evidence.

Objective: To examine whether age of first use or frequency of use of cannabis is associated with anxiety and depression (AD) in young adults, independent of known potential confounders, including the use of other illicit drugs. Method: A cohort of 3,239 Australian young adults was followed from birth to the age of 21 when data on AD were obtained from sample members along with information on their use of cannabis at 21 years. Potential confounding factors were prospectively measured when the child was born and at 14 years. Results: After controlling for confounding factors, those who started using cannabis before age 15 years and used it frequently at 21 years were more likely to report symptoms of AD in early adulthood (odds ratio 3.4; 95% CI 1.9Y6.1). This association was of similar magnitude for those who had only used cannabis and those who reported having used cannabis and other illicit drugs. Conclusion: The relationship between early-onset and frequent use of cannabis and symptoms of AD is independent of individual and family backgrounds.

Background Alcohol, tobacco, and illegal drug use cause considerable morbidity and mortality, but good cross-national epidemiological data are limited. This paper describes such data from the first 17 countries participating in the World Health Organization's (WHO's) World Mental Health (WMH) Survey Initiative.

To examine predictors of cannabis use initiation, continuity and progression to daily use in adolescents. Design. Population-based cohort study over 3 years with 6 waves of data collection. Participants. 2032 students, initially aged 14-15 years, from 44 secondary schools in the state of Victoria, Australia. Measurements. Self-report cannabis use was categorized on four levels (none, any, weekly, daily) and summarized as mid-school (waves 2/3) and late-school (waves 4/5/6) use. Background, school environment, mid-school peer use and individual characteristics were assessed. Findings. Peer cannabis use, daily smoking, alcohol use, antisocial behaviour and high rates of school-level cannabis use were associated with mid-school cannabis use and independently predicted late-school uptake. Cannabis use persisted into late-school use in 80% of all mid-school users. Persisting cannabis use from mid-to late-school was more likely in regular users (odds ratio (OR) 3.4), cigarette smokers (OR any smoking: 2.0, daily smoking: 3.3) and those reporting peer use (OR 2.1). Mid-school peer use independently predicted incident late-school daily use in males (OR 6.5) while high-dose alcohol use (OR 6.1) and antisocial behaviour (OR 6.6) predicted incident late-school daily use in females. Conclusions. Most cannabis use remained occasional during adolescence but escalation to potentially harmful daily use in the late-school period occurred in 12% of early users. Transition was more likely in males, for whom availability and peer use were determinants. In contrast, females with multiple extreme behaviours were more likely to become daily users. Cigarette smoking was an important predictor of both initiation and persisting cannabis use.

Implementation fidelity, a critical aspect of clinical trials research that establishes adequate delivery of the treatment as prescribed in treatment manuals and protocols, is also essential to the successful implementation of effective programs into new practice settings. Although infrequently studied in the drug abuse field, stronger implementation fidelity has been linked to better outcomes in practice but appears to be more difficult to achieve with greater distance from model developers. In the INternational CAnnabis Need for Treatment (INCANT) multinational randomized clinical trial, investigators tested the effectiveness of Multidimensional Family Therapy (MDFT) in comparison to individual psychotherapy (IP) in Brussels, Berlin, Paris, The Hague, and Geneva with 450 adolescents with a cannabis use disorder and their parents. This study reports on the implementation fidelity of MDFT across these five Western European sites in terms of treatment adherence, dose and program differentiation, and discusses possible implications for international implementation efforts.

Aims A brief intervention called the Marijuana Checkup (MCU) was designed to attract adult marijuana users who were experiencing adverse consequences, but who were ambivalent about change and would be unlikely to seek treatment. Our objective was to determine whether the MCU would reach the target population. Design Comparisons were made between those who enrolled in the MCU versus those who were screened but failed to follow through with enrollment on demographic, drug use and stage of change variables. Comparisons were also made between participants in the MCU and participants in a concurrently offered treatment project that targeted marijuana users who wanted to quit. Setting The study took place at the University of Washington in Seattle. Participants Participants were adult marijuana users who telephoned and expressed interest in the MCU (n = 587). Measurement Study variables included stage of change, frequency and duration of drug use, DSM-IV cannabis dependence and abuse diagnoses and negative consequences of marijuana use assessed via interviews and questionnaires. Findings Callers to the MCU were near-daily marijuana users, two-thirds of whom were in the pre-contemplation or contemplation stage of change. Participants who enrolled in the MCU reported fewer problems related to marijuana use and less readiness to make changes compared to those enrolled in the treatment study, despite similar levels of drug use. Conclusions The MCU attracted and enrolled near-daily users of marijuana who experienced negative consequences but were ambivalent about making changes. The MCU potentially has a role in the continuum of care for substance abuse problems.

Sixty-two individuals seeking treatment for marijuana dependence completed a comprehensive assessment. Sociodemographics, substance use, psychosocial functioning, psychiatric symptoms, and medical status were compared with similar data collected from 70 treatmentseeking, cocaine-dependent individuals. Substantial psychosocial and psychiatric problems were observed in both groups. In general, the marijuana group reported substance-use histories and a range of impairment comparable with the cocaine group; however, they showed less severe dependence. The marijuana group was more ambivalent and less confident about stopping their marijuana use than the cocaine group was about stopping their cocaine use. These findings indicate that treatment-seeking, marijuana-dependent individuals exhibit substantial problems and that further efforts to develop effective treatments for this population are warranted.

Cannabis use is highly prevalent among people with schizophrenia, and coupled with impaired cognition, is thought to heighten the risk of illness onset. However, while heavy cannabis use has been associated with cognitive deficits in long-term users, studies among patients with schizophrenia have been contradictory. This article consists of 2 studies. In Study I, a meta-analysis of 10 studies comprising 572 patients with established schizophrenia (with and without comorbid cannabis use) was conducted. Patients with a history of cannabis use were found to have superior neuropsychological functioning. This finding was largely driven by studies that included patients with a lifetime history of cannabis use rather than current or recent use. In Study II, we examined the neuropsychological performance of 85 patients with first-episode psychosis (FEP) and 43 healthy nonusing controls. Relative to controls, FEP patients with a history of cannabis use (FEP 1 CANN; n 5 59) displayed only selective neuropsychological impairments while those without a history (FEP 2 CANN; n 5 26) displayed generalized deficits. When directly compared, FEP 1 CANN patients performed better on tests of visual memory, working memory, and executive functioning. Patients with early onset cannabis use had less neuropsychological impairment than patients with later onset use. Together, these findings suggest that patients with schizophrenia or FEP with a history of cannabis use have superior neuropsychological functioning compared with nonusing patients. This association between better cognitive performance and cannabis use in schizophrenia may be driven by a subgroup of ''neurocognitively less impaired'' patients, who only developed psychosis after a relatively early initiation into cannabis use.

s Abstract Background This is an epidemiological study of a possible causal role of marijuana use in the development of Major Depressive Episode (MDE). Malefemale differences in the suspected causal association have also been studied. Method Data are from 6,792 National Comorbidity Survey participants aged 15-45 years, assessed via the University of Michigan modified version of the Composite International Diagnostic Interview (UM-CIDI). Survival analysis methods were used to estimate cumulative risk of MDE by levels of marijuana use and to estimate suspected causal associations after adjustment for other influences. Results The risk of first MDE was moderately associated with the number of occasions of marijuana use and with more advanced stages of marijuana use. Relative to never users, non-dependent marijuana users had 1.6 times greater risk of MDE (95 % Confidence Interval: 1.1, 2.2), even with statistical adjustment for sex, birth cohorts, alcohol dependence, and history of daily tobacco smoking. Conclusions There was male-female variation in the degree of association between stage of marijuana involvement and MDE, but the strength of the association is modest at best.

Accumulating evidence suggests neuropsychological deficits from cannabis use, with a burgeoning area of preclinical research indicating possible sex-differences. However, few studies have examined how cannabis use may differentially impact neurocognition in male and female cannabis users. As such, we examined potential sex-differences in associations between amount of cannabis use (across several time-frames) and neurocognitive performance among young adult regular cannabis users. Consistent with previous studies, more cannabis use was generally associated with poorer episodic memory and decision-making, but not other measures of inhibitory control. However, patterns of results suggested sex-specific dissociations. In particular, more cannabis use was more consistently associated with poorer episodic memory performance in females than males. Conversely, more cannabis use was associated with poorer decision-making performance for males, but not females. These results provide further evidence for residual cannabis-associated neurocognitive deficits and suggest the importance of examining the impact of cannabis on neurocognition separately for males and females.

Objective: We sought to identify (a) the course of changes in smoking, alcohol and marijuana use, violence, and sexual behavior from early adolescence through young adulthood for males and females, (b) points of divergence and convergence for 5 health risk behaviors between males and females, and (c) whether the trajectories of change in health risk behaviors differed for males and females. Method: Data from four waves of the nationally representative National Longitudinal Study of Adolescent Health (Add Health) followed 18,911 youth from early adolescence through the transition to adulthood (ages13 through 31 years) and were analyzed using zero-inflated negative binomial growth models and logistic growth models. Results: Generally, health risk behaviors steadily increased through adolescence into the early 20s, subsequently leveling off or decreasing. Results indicated early adolescent females were more likely to smoke and have more sexual partners, and 14-and 18-year-old females had higher rates of increase for getting drunk. The majority of findings, however, indicated that adolescent and young adult males engaged in more risk behaviors and were increasingly likely to engage over time. Among youth engaged in health risk behaviors, males reported greater frequency and increases in rates over time for most risk behaviors. Conclusions: We identify several critical groups for health professionals to address: early adolescent females not previously identified as more engaged in health risks; adolescent females "catching up" to male health risks; early and mid-adolescent males shifting into adult patterns of heightened health risk behaviors; and the group of risk-taking males across age groups.

Computational neuroscience integrate-and-fire attractor network models can be used to understand the factors that alter the stability of cortical networks in the face of noise caused for example by neuronal spiking times. A reduction of the firing rates of cortical neurons caused for example by reduced NMDA receptor function (present in schizophrenia) can lead to instability of the high firing rate attractor states that normally implement short-term memory and attention, contributing to the cognitive and negative symptoms of schizophrenia. Reduced cortical inhibition caused by a reduction of GABA neurotransmission (present in schizophrenia) can lead to instability of the spontaneous firing states of cortical networks, leading to a noise-induced jump to a high firing rate attractor state even in the absence of external inputs, contributing to the positive symptoms of schizophrenia. We consider how effects occurring at the time of late adolescence including synaptic pruning, decreases in grey matter volume, and changes in GABAmediated inhibition and dopamine may contribute to the onset in some individuals of schizophrenia at this time.

We examined three components of the ''gateway theory'' in relation to marijuana use: (1) whether adolescent marijuana use predicts young adult drug use, (2) whether this association persists when controlling for similar family background, (3) whether common genetic or environmental factors contribute to the association. The three components were tested in adolescents from the National Longitudinal Study of Adolescent Health assessed twice during adolescence and then re-interviewed 5 years later. Component 1 was tested in 18,286 subjects, component 2 in sibling pairs (n=360) discordant for marijuana use, and component 3 in a genetically informative sub-sample (n=4846). Marijuana use was defined as any use during adolescence, and drug use was defined as self-reported past year use of other illicit drugs besides marijuana. Marijuana users were twice as likely to use illicit drugs as young adults than non-users. Shared environmental factors mediated much of the relationship between adolescent marijuana use and young adult drug use. The association remained, however, even when controlling for familial environmental and other measured factors.

Aims To investigate the triggering effects of alcohol, illegal substances and major classes of prescribed psychotropic drugs on criminal violence. Design A case-crossover design, using each subject as its own control. Setting and participants A consecutive sample of 133 violent offenders was recruited from a forensic psychiatric evaluation unit and a national prison evaluation unit in Sweden during 2002-03. Measurements Offenders were assessed with structured interviews. Risk estimates were based on hazard periods of 24 hours. We used standard Mantel-Haenszel methods for statistical analyses. Findings A 13.2-fold increase of risk of violence [95% confidence interval (CI): 8.2-21.2] was found within 24 hours of alcohol consumption. This increase in violence risk was similar among individuals combining alcohol with benzodiazepines [Relative risk (RR) = 13.2, 95% CI: 4.9-35.3]. Use of benzodiazepines alone in regular doses (RR = 0.4, 95% CI: 0.2-0.5) or antidepressants [selective serotonin reuptake inhibitors (SSRIs) or tricyclics] (RR = 0.4, 95% CI: 0.3-0.8) was associated with a lowered risk for violence. Conclusions This study confirmed that alcohol is a strong trigger of criminal violence. Benzodiazepines in combination with alcohol caused no further increase of violence risk. Benzodiazepines in regular doses and antidepressants may inhibit violence, but further studies are needed to verify causality. The case-crossover method can contribute to research on the proximal causes of criminal violence.

Although there has been considerable research into the adverse effects of cannabis, less attention has been directed toward subjective effects that may be associated with ongoing cannabis use. Examination of self-reported cannabis effects is an important issue in understanding the widespread use of cannabis. While reviews have identified euphoria as a primary factor in maintaining cannabis use, relaxation is the effect reported most commonly in naturalistic studies of cannabis users, irrespective of the method used. Self-reported effects in 12 naturalistic and 18 laboratory studies were compared. Regardless of methodology there was considerable variation in the effects experienced. Variation has been reported in terms of opposite effects being experienced by different individuals, variation of effects by individuals within a single occasion and between occasions of use. Factors that might explain this variation are outlined. Limitations of the available literature and suggested directions for future research are discussed. [Green B, Kavanagh D, Young R. Being stoned: a review of self-reported cannabis effects. Drug Alcohol Rev 2003;22:453 -460]

The present study examined the influence of ethnicity on the effectiveness of cognitive behavioral treatment for PTSD in female victims of sexual and nonsexual assault. Ninety-five women with chronic PTSD (60 Caucasian and 35 African American) were randomly assigned to either active cognitive behavioral treatment or wait list control. Active treatment consisted of nine, twice-weekly, individual sessions of prolonged exposure, stress inoculation training, or a combination. Independent evaluations were conducted at pretreatment, posttreatment, and 12-month follow-up. African Americans and Caucasians did not differ in terms of pretreatment psychopathology or general functioning, dropout rates from treatment, or overall treatment efficacy. These results are discussed within the context of the need for future exploration of ethnocultural factors in the treatment of PTSD.

Cannabis is the most commonly used illicit substance worldwide. Despite this, its impact on sexual health is largely unknown. Aim. The aim of this article is to examine the association between cannabis use and a range of sexual health outcomes. Main Outcome Measures. The main outcome measures include the number of sexual partners in the past year, condom use at most recent vaginal or anal intercourse, diagnosis with a sexually transmissible infection in the previous year, and the occurrence of sexual problems. Methods. Method used in this article includes a computer-assisted telephone survey of 8,656 Australians aged 16-64 years resident in Australian households with a fixed telephone line. Results. Of the 8,650 who answered the questions about cannabis use, 754 (8.7%) reported cannabis use in the previous year with 126 (1.5%) reporting daily use, 126 reported (1.5%) weekly use, and 502 (5.8%) reported use less often than weekly. After adjusting for demographic factors, daily cannabis use compared with no use was associated with an increased likelihood of reporting two or more sexual partners in the previous year in both men (adjusted odds ratio 2.08, 95% confidence interval 1.11-3.89; P = 0.02) and women (2.58, 1.08-6.18; P = 0.03). Daily cannabis use was associated with reporting a diagnosis of a sexually transmissible infection in women but not men (7.19, 1.28-40.31; P = 0.02 and 1.45, 0.17-12.42; P = 0.74, respectively). Frequency of cannabis use was unrelated to sexual problems in women but daily use vs. no use was associated with increased reporting among men of an inability to reach orgasm (3.94, 1.71-9.07; P < 0.01), reaching orgasm too quickly (2.68, 1.41-5.08; P < 0.01), and too slowly (2.05, 1.02-4.12; P = 0.04). Conclusions. Frequent cannabis use is associated with higher numbers of sexual partners for both men and women, and difficulties in men's ability to orgasm as desired. Smith AMA, Ferris JA, Simpson JM, Shelley J, Pitts M, and Richters J. Cannabis use and sexual health. J Sex Med 2010;7:787-793.

Exposure to traumatic events is common among individuals with substance use disorders (SUD), although not all go on to develop PTSD. We compared SUD treatment outcomes and relapse features in three groups of male veterans receiving SUD treatment: (1) those without trauma exposure (SUD-only; n=68), (2) those with PTSD (SUD-PTSD; n=32), and (3) those with trauma exposure but no PTSD

Chronic marijuana use has been associated with impairments of learning, memory, and executive functions. Little is known, however, about the effects of marijuana use on other cognitive domains, such as decision-making, which are thought to play an important role in addiction and drug abuse. The purpose of the present study was to determine if long-term heavy marijuana users employ different decision-making strategies than individuals with minimal marijuana exposure. Volunteers were assigned to a cannabis (n = 10) or control group (n = 10) based upon history of prior marijuana use. Demographic and neuropsychological variables were evaluated, and a decision-making task--the gambling task (GT) was administered. Although few demographic and neuropsychological differences were noted between groups, marijuana users made more decisions that led to larger immediate gains despite more costly losses than controls. These data suggest that long-term heavy marijuana users may have specific deficits in the ability to balance rewards and punishments that may contribute to continued drug-taking behavior. It is unknown, however, whether the basis for such deficits might be attributed directly to marijuana exposure or pre-existing genetic or behavioral differences.

Introduction. Cannabis use is strongly associated with the use and abuse/dependence of other illicit drugs. Gateway and common liabilities models have been employed to explain this relationship. We sought to examine this association using a combination of the discordant twin design and modeling methods.Method. We assess the relationship between early cannabis use and the subsequent use and abuse/dependence of other illicit drugs in a population-based sample of male and female twin pairs using four analyses: (i) analysis of the association between early cannabis use and other illicit drug use and abuse/dependence in the entire sample of twins, (ii) assessment of the influence of early cannabis use in twin 1 on twin 2&#39;s use or abuse/dependence of other illicit drugs, (iii) use of twin pairs discordant for early cannabis use in a discordant twin design and (iv) a model-fitting procedure.Results. We found: (i) a strong association between early cannabis use and use and abuse/depende...

Aim To evaluate the relationship between change in cannabis use and changed cognitive performance over 8 years. Design We used survey methodology with a cohort design. Setting and participants An Australian community sample aged 20-24 years at baseline. Measures We assessed cognitive performance with the California Verbal Learning Test (CVLT) (immediate and delayed), Spot-the-Word test (STW), Symbol Digit Modality test (SDMT) and Digit Backwards (DB). Groups of cannabis users were defined from self-reports across three waves as: 'never' (n = 420) 'remain light' (n = 71), 'former light' (n = 231), 'remain heavy' (n = 60), 'former heavy' (n = 60) and 'always former' (since start of study) (n = 657). Planned contrasts within mixed model repeated-measures analysis of variance was used for longitudinal analysis with an adjusted alpha of 0.01. Findings Data were obtained from 2404 participants with 1978 (82.3%) completing wave 3. At baseline there were significant differences between cannabis groups on CVLT (immediate and delayed) and SDMT. However, after controlling for education, gender, gender ¥ group and gender ¥ wave, there were no significant between-group differences and only CVLT immediate recall reached adjusted statistically significant longitudinal change associated with changed cannabis use (group ¥ wave P = 0.007). Specifically, former heavy users improved their performance relative to remaining heavy users (estimated marginal means: former heavy 6.1-7.5: remain heavy 6.4-6.6). Conclusions Cessation of cannabis use appears to be associated with an improvement in capacity for recall of information that has just been learned. No other measures of cognitive performance were related to cannabis after controlling for confounds.

The authors examined the relations between participation in a range of high school extracurricular contexts and developmental outcomes in adolescence and young adulthood among an economically diverse sample of African American and European American youths. In general, when some prior self-selection factors were controlled, 11th graders' participation in school clubs and organized sports was associated with concurrent indicators of academic and psychological adjustment and with drug and alcohol use. In addition, participation in 11th grade school clubs and prosocial activities was associated with educational status and civic engagement at 1 year after high school. A few of the concurrent and longitudinal relations between activity participation and development were moderated by race and gender. Finally, breadth of participation, or number of activity contexts, was associated with positive academic, psychological, and behavioral outcomes.

The effectiveness of a 20 session cognitive-behavioral approach to substance abuse prevention was tested on seventh grade students ( n = 1,311) from 10 suburban New York junior high schools. The prevention strategy attempted to reduce intrapersonal pressure to smoke, drink excessively, or use marijuana by fostering the development of general life skills as well as teaching students tactics for resisting direct interpersonal pressure to use these substances. Additionally, this study was designed to compare the relative effectiveness of this type of prevention program when implemented by either older peer leaders or regular classroom teachers. Results indicated that the prevention program had a significant impact on cigarette smoking, excessive drinking, and marijuana use when implemented by peer leaders. Furthermore, significant changes were also evident with respect to selected cognitive, attitudinal, and personality predisposing variables in a direction consistent with non-substance use. These results provide further support for the efficacy of a broad-spectrum smoking prevention strategy and tentative support for its applicability to the prevention of other forms of substance abuse.

In the past decade we have seen an increasing number of newborns born to substanceabusing mothers. The pattern and incidence of drug abuse has changed in the recent years.'-3 Previously, we saw babies born to mothers taking heroin, alcohol, methadonemaintenance, and "pills." At present the most used drugs are cocaine, marijuana with or without alcohol, and occasional heroin and PCP. All these drugs cross the placenta and enter the fetus. With this change in the drug abuse pattern, we are seeing an increase in the incidence of obstetrical complications such as abruptio placentae, premature labor, fetal distress, venereal and a higher admission rate of premature and asphyxiated infants in our neonatal intensive care units. There has been a surge of reports in both the medical and lay literature on the effects of cocaine on pregnancy and on the neonate. These reports have described neonates with decreased birth weight and length and head circumferences; central nervous system abnormalities and cerebral infarcts, a syndrome of increased tone, abnormal movements, irritability and increased deep tendon reflexes, abnormal EEGs and evoked visual potentials; and genitourinary abnormalities.'-'* It should be remembered, however, that cocaine was one of several drugs abused by many of these mothers.

With growing interest in online assessment of substance abuse behaviors, there is a need to formally evaluate the validity of the data gathered. The current investigation evaluated the reliability and validity of anonymous, online reports of young adults' marijuana use and related cognitions. Young adults age 18 to 25 who had smoked at least one cigarette in the past 30 days were recruited over 14 months to complete an anonymous online survey. Of 3106 eligible cases, 1617 (52%) completed the entire survey. Of those, 54% (n = 884) reported past-month marijuana use (65% male, 70% Caucasian, mean age was 20.4 years [SD = 2.0]). Prevalence of marijuana use was reported reliably across three similar items, and inter-item correlations ranged from fair to excellent for measures of marijuana dependence symptoms and thoughts about marijuana use. Marijuana use frequency demonstrated good construct validity through expected correlations with marijuana use constructs, and non-significant correlations with thoughts about tobacco use. Marijuana frequency distinguished among stages of change for marijuana use and goals for use, but not among gender, ethnicity, or employment groups. Marijuana use and thoughts about use differed by stage of change in the hypothesized directions. Self-reported marijuana use and associated cognitions reported anonymously online from young adults are generally reliable and valid. Online assessments of substance use broaden the reach of addictions research.

An economic evaluation of five outpatient adolescent treatment approaches (12 total site-byconditions) was conducted. The economic cost of each of the 12 site-specific treatment conditions was determined by the Drug Abuse Treatment Cost Analysis Program (DATCAP). Economic benefits of treatment were estimated by first monetizing a series of treatment outcomes and then analyzing the magnitude of these monetized outcomes from baseline through the 12month follow-up. The average economic costs ranged from $90 to $313 per week and from $839 to $3,279 per episode. Relative to the quarter before intake, the average quarterly cost to society for the next 12 months (including treatment costs) significantly declined in 4 of the 12 site-bytreatment conditions, remained unchanged in 6 conditions, and increased in 2 treatment conditions (both in the same site). These results suggest that some types of substance-abuse intervention for adolescents can reduce social costs immediately after treatment.

Data from three outpatient studies of treatment of marijuana dependence were used to test whether behavior change parallels stage movement in the transtheoretical model of change (TMC). This study examined one putative assumption of the TMC: individuals remaining in the preaction stages of change (i.e., precontemplation and contemplation) across time would show little change in their marijuana use. The University of Rhode Island Change Assessment (URICA) measure and two recent stage assignment algorithms were utilized to assess TMC stage status at baseline and end of treatment. The primary analyses employed paired-sample t tests of statistical equivalence and sign tests, and 34 out of the 36 tests demonstrated that individuals remaining in the preaction stages of change over the treatment period showed clinically important and statistically significant treatment outcomes. Clinicians and researchers should exercise caution in their use of URICA-based indices as meaningful markers of the recovery process. Better methods to measure stage status and test the TMC are needed if the model is to be used to guide substance abuse interventions.

Despite the widespread abuse of marijuana, knowledge about its effects in the human brain is limited. Brain glucose metabolism with and without Δ 9 tetrahydrocannabinol (THC) (main psychoactive component of marijuana) was evaluated in eight normal subjects and eight ...

The Canadian Special Senate Committee on Illegal Drugs noted that little ethnographic research had been devoted to exploring why people use marijuana recreationally or the social contexts in which it is used. The purpose of this exploratory qualitative research is to better understand both of these neglected topics through interviews conducted with 41 adult Canadian users between 2005 and 2006. The participants' ages ranged from 21 to 61 and included 25 males and 16 females whose consumption patterns ranged from sporadic use to regular daily use. They were predominantly middle class, employed in a wide range of occupations, and used marijuana recreationally to enhance relaxation and concentration while engaged in leisure activities. Implications for drug laws and policies are discussed. The study's limitations are noted.

Little is known about how different types of substances affect oral health. Our objective was to examine the respective effects of alcohol, stimulants, opioids, and marijuana on oral health in substance-dependent persons. Using self-reported data from 563 substance-dependent individuals, we found that most reported unsatisfactory oral health, with their most recent dental visit more than 1 year ago. In multivariable logistic regressions, none of the substance types were significantly associated with oral health status. However, opioid use was significantly related to a worse overall oral health rating compared to 1 year ago. These findings highlight the poor oral health of individuals with substance dependence and the need to address declining oral health among opioid users. General health and specialty addiction care providers should be aware of oral health problems among these patients. In addition, engagement into addiction and medical care may be facilitated by addressing oral health concerns.

Aims To evaluate the efficacy of a two-session assessment and feedback intervention designed to reach and increase motivation for change in marijuana users who were experiencing negative consequences but were ambivalent about change. Design Random assignment to one of two types of feedback conditions or a delayed feedback control (DFC) with follow-up assessments at 7 weeks, 6 months and 12 months. Setting University of Washington research center in Seattle, Washington. Participants A total of 188 adult male and female marijuana users who responded to advertisements. Interventions A personalized feedback (PF) condition utilizing motivational interviewing was compared to an educational control condition labeled multi-media feedback (MMF). Measurements Marijuana use, dependence symptoms, other associated negative consequences and motivational constructs were assessed at all time-points. Findings PF participants reported fewer days of use per week, fewer periods of use per day and fewer dependence symptoms at 7 weeks than those in the MMF and DFC conditions. PF participants also reported fewer days of use per week compared to MMF participants at the 12-month follow-up and fewer dependence symptoms at both the 6-and 12-month follow-ups compared to MMF participants. Conclusions The PF intervention, delivered in the context of a check-up, shows potential as a way of reaching and motivating change in marijuana users with a diagnosable disorder who otherwise are not ready to approach treatment. Ways of augmenting the modest absolute levels of change are discussed.

In this study, the authors examined the relation between adolescent and parent therapeutic alliances and treatment outcome among 65 substance-abusing adolescents receiving multidimensional family therapy. Observer ratings of parent alliance predicted premature termination from treatment. Observer ratings, but not self-report, of adolescent alliance predicted adolescents' substance abuse and dependency symptoms at posttreatment, as well as days of cannabis use at 3-month follow-up. The association between adolescent alliance and substance abuse and dependency symptoms at posttreatment was moderated by the strength of the parent alliance. Results reveal the unique and interactive effects of the 2 alliances on treatment outcome and emphasize the need for a systemic and well-articulated approach to developing and maintaining the multiple alliances inherent to family therapy.

The Severity of Dependence Scale (SDS) is a five-item scale that has been reported to be a reliable and valid screening instrument for dependence and a measure of dependence severity in adults across several substance classes. To date no data have been reported on its performance in a population of adolescent cannabis users. The current study assessed the psychometric properties of the SDS in a community sample of 14–18-year-old adolescent cannabis users (n = 100). Internal consistency (α = 0.83) and test–retest coefficients (ICC = 0.88) were high and a principal components analysis of the scale found all items to load on a single factor. Total SDS score correlated significantly with frequency of cannabis use and number of DSM-IV dependence criteria met, indicating good concurrent validity. Receiver Operating Characteristic curve analysis was used to determine the most appropriate SDS cut-off score for use as an indicator of cannabis dependence, with optimal discrimination at an SDS score of 4. These findings indicate that the SDS is a reliable and valid measure of severity of cannabis dependence among adolescents, has high diagnostic utility, and that an SDS score of 4 may be indicative of cannabis dependence.

Introduction : Cannabis is the world's most popular illicit drug. Episodic memory in long-term users has been frequently investigated but little research has examined the impact of cannabis use on semantic memory. Psychotic symptoms such as thought disorder have also been theoretically linked to semantic memory impairments in patients with schizophrenia. In addition to investigating the long-term effects of cannabis on semantic memory, this study also aimed to investigate if any schizophrenia-like symptoms observed in this population were related to semantic memory abnormalities. Method: In a naturalistic study (n=74) using an acute-onchronic and chronic design, 36 cannabis users were compared with 38 controls whilst under the influence of cannabis and then three to five days later when participants were not intoxicated. Drug use was verified by urinanalysis. Semantic memory was assessed using a semantic priming task with both a long and short stimulus onset asynchrony (SOA) to assess automatic and controlled semantic processing. State and trait schizotypy were also indexed. Results: Under the influence of cannabis, users showed increased automatic semnatic priming and schizotypal symptoms than controls. Three to five days later following abstinence from cannabis, users exhibited hyper-priming at long SOAs on a direct priming task with a trend for reduced priming at the short SOA. Cannabis users did not differ in trait schizotypy and were similar to controls on state schizotypy when not intoxicated. Conclusions: Acutely, cannabis increases semantic priming which may be related to some of the psychotomimetic effects of the drug. Regular cannabis use produces semantic abnormalities when not under the influence of the drug. The pattern of long-term semantic abnormalities differs markedly from those observed in patients with schizophrenia and looks similar to that observed in individuals scoring highly on a schizotypy scale.