Association between cannabis use and symptom dimensions in schizophrenia spectrum disorders: an individual participant data meta-analysis on 3053 individuals.

Background: The association between cannabis use and positive symptoms in schizophrenia spectrum disorders is well documented, especially via meta-analyses. Yet, findings are inconsistent regarding negative symptoms, while other dimensions such as disorganization, depression, and excitement, have not been investigated. In addition, meta-analyses use aggregated data discarding important confounding variables which is a source of bias. Methods: PubMed, ScienceDirect and PsycINFO were used to search for publications from inception to September 27, 2022. We contacted the authors of relevant studies to extract raw datasets and perform an Individual Participant Data meta-analysis (IPDMA). Inclusion criteria were: psychopathology of individuals with schizophrenia spectrum disorders assessed by the Positive and Negative Syndrome Scale (PANSS); cannabis-users had to either have a diagnosis of cannabis use disorder or use cannabis at least twice a week. The main outcomes were the PANSS subscores extracted via the 3-factor (positive, negative and general) and 5-factor (positive, negative, disorganization, depression, excitement) structures. Preregistration is accessible via Prospero: ID CRD42022329172. Findings: Among the 1149 identified studies, 65 were eligible and 21 datasets were shared, totaling 3677 IPD and 3053 complete cases. The adjusted multivariate analysis revealed that relative to non-use, cannabis use was associated with higher severity of positive dimension (3-factor: Adjusted Mean Difference, aMD = 0.34, 95% Confidence Interval, CI = [0.03; 0.66]; 5-factor: aMD = 0.38, 95% CI = [0.08; 0.63]), lower severity of negative dimension (3-factor: aMD = -0.49, 95% CI [-0.90; -0.09]; 5-factor: aMD = -0.50, 95% CI = [-0.91; -0.08]), higher severity of excitement dimension (aMD = 0.16, 95% CI = [0.03; 0.28]). No association was found between cannabis use and disorganization (aMD = -0.13, 95% CI = [-0.42; 0.17]) or depression (aMD = -0.14, 95% CI = [-0.34; 0.06]). Interpretation: No causal relationship can be inferred from the current results. The findings could be in favor of both a detrimental and beneficial effect of cannabis on positive and negative symptoms, respectively. Longitudinal designs are needed to understand the role of cannabis is this association. The reported effect sizes are small and CIs are wide, the interpretation of findings should be taken with caution. Funding: This research did not receive any specific grant or funding. Primary financial support for authors was provided by Le Vinatier Psychiatric Hospital.

Case report for an internet- and mobile-based intervention for internet use disorder.

Background and aims: Internet use disorder (IUD), characterized as the inability to control one's internet use, is associated with reduced quality of life and mental health comorbidities such as depression, substance abuse, or anxiety. Evidence-based treatment options are scarce due to the novelty of the diagnosis. Internet- and mobile-based interventions (IMI) may be an effective means to deliver psychological treatment to individuals with IUD as they address affected individuals in their online setting. This study presents a newly developed IMI for IUD disclosing treatment satisfaction and preliminary effects by exemplifying with a case report. Methods: The case of a female participant with IUD, characterized by an excessive use of social media, is analyzed. The case report follows the CARE guidelines and presents qualitative and quantitative outcomes regarding potential symptom reduction measured by the Internet Addiction Test (IAT) and Compulsive Internet Use Scale (CIUS), treatment satisfaction measured by the Client Satisfaction Questionnaire (CSQ) and feasibility by analyzing participant's written feedback during treatment. Results: The case report shows that internet- and mobile-based interventions may be feasible in supporting an individual in reducing symptoms of IUD as well as depressive symptoms, anxiety and procrastination behavior. Treatment satisfaction was reported as good. Discussion and conclusions: This case report illustrates that IMIs can have the potential to be an easily accessible and possibly effective treatment option for IUD. Case studies on IMIs may provide insights into important mechanisms for symptom change. Further studies are needed to expand our understanding of this diverse disorder to provide adequate treatment. Clinical Trial Registration: https://clinicaltrials.gov/,DRKS00015314.

Predictors of Youth Accessibility for a Mobile Phone-Based Life Skills Training Program for Addiction Prevention.

BACKGROUND: Digital interventions are an emerging and promising avenue for addiction prevention and mental health promotion, but their reach and use are often limited, and little is known about the factors associated with youth accessibility. SmartCoach is a life skills training program for addiction prevention where adolescents are proactively invited for program participation in secondary school classes. The mobile phone-based program provides individualized coaching for a period of 4 months and addresses self-management skills, social skills, and substance use resistance skills. This study examined sociodemographic and other predictors of program participation and program use. METHODS: A total of 476 adolescents in 28 secondary and upper secondary school classes in the German-speaking part of Switzerland were proactively invited for participation in the SmartCoach program. Using generalized linear mixed models (GLMMs), we examined predictors of both program participation and program use at the individual and school class levels. RESULTS: In total, 315 (66.2%) of the present 476 adolescents gave their active consent and provided the necessary information to be included in the program. None of the individual sociodemographic characteristics significantly predicted program participation, however, the participation rate was significantly higher in upper secondary school classes (84%) than secondary school classes (59%). The mean number of interactions with the program was 15.9, i.e., participants took part in almost half of the 34 possible interactions with the SmartCoach program. None of the baseline characteristics on the level of the school class significantly predicted program use. On the level of the individual, the univariate models showed that, compared to the reference category of 14-year-old students, program use was significantly lower for students who were 16 or older. Furthermore, participants with a migration background or an origin from a non-German-speaking country showed significantly lower program use. Finally, students with a medium level of perceived stress showed higher program use compared to those with a low level of stress. Within the final multivariate model for program use, only the variable "origin from a non-German-speaking country" remained significant. CONCLUSIONS: SmartCoach is an attractive offer for young people, in which two out of three young people who are invited in the classroom to participate do so. Among the program participants, the use of the program is acceptable, with an average of almost half of the content being worked on. There is potential for improvement in terms of recruitment, especially in school classes with a lower level of education. The most important starting point for improving program use lies in taking greater account of needs and wishes of students with non-German-speaking countries of origin.

Mobile App-Based Coaching for Alcohol Prevention among Adolescents: Pre-Post Study on the Acceptance and Effectiveness of the Program "MobileCoach Alcohol".

BACKGROUND: At-risk alcohol use, particularly binge drinking, is widespread among adolescents and young adults in most Western countries. MobileCoach Alcohol is a mobile app-based program for alcohol prevention that provides individualized coaching using a conversational agent. The current study tested the acceptance, use, and evaluation of this newly developed program and explored its potential effectiveness. METHODS: Longitudinal pre-post study among upper secondary and vocational school students in Switzerland. Within the MobileCoach Alcohol prevention program, a virtual coach motivated participants to deal with alcohol sensitively, and provided feedback on alcohol use and strategies to resist alcohol for a period of 10 weeks. Information was provided in weekly dialogs, within contests with other participants, and interactive challenges. By means of a follow-up survey after the end of the 10-week program, indicators of the use, acceptance, and effectiveness of the program were examined. RESULTS: Between October 2020 and July 2022, the program was advertised in upper secondary and vocational schools. Recruiting schools and school classes was difficult due to the COVID-19 containment measures in place during this period. Nevertheless, the program could be implemented in 61 upper secondary and vocational school classes with a total of 954 participating students. Three out of four students who were present in the school classes participated in the MobileCoach Alcohol program and the associated study. Online follow up assessment at week 10 was completed by 272 program participants (28.4%). Based on program use and evaluations by the participants, the overall acceptance of the intervention was good. The proportion of students who engaged in binge drinking was significantly reduced from 32.7% at baseline to 24.3% at follow up. Furthermore, the longitudinal analyses revealed decreases in the maximum number of alcoholic drinks consumed on an occasion and the mean number of standard drinks per month, whereas self-efficacy to resist alcohol increased between baseline and follow up. CONCLUSIONS: The mobile app-based MobileCoach Alcohol program proved to be an attractive intervention, in which the majority of students were interested when proactively recruited at school classes. It allows for individualized coaching in large groups of adolescents and young adults and is promising for reducing at-risk alcohol use.

Efficacy of a Mobile App-Based Coaching Program for Addiction Prevention among Apprentices: A Cluster-Randomized Controlled Trial.

BACKGROUND: Addictive behaviors such as tobacco/e-cigarette smoking, at-risk alcohol consumption, cannabis use or compulsive internet use are common among apprentices. ready4life is a mobile app-based preventive intervention program for apprentices that promotes life skills and reduces risky behavior. The present study tested the efficacy of ready4life for addiction prevention among apprentices in Switzerland within a controlled trial. METHODS: Two-arm, cluster-randomized controlled trial including assessments at baseline and follow-up after 6 months. Participants of the intervention group received coaching by a conversational agent for 16 weeks. The main outcome measure was a composite score for addictive behaviors, which included (1) at-risk drinking, (2) tobacco/e-cigarette smoking, (3) cannabis use and (4) problematic internet use. RESULTS: A total of 2275 students from 159 vocational school classes in Switzerland, were invited for study participation. Of these, 1351 (59.4%) students with a mean age of 17.3 years and a male proportion of 56.6% provided informed consent to participate. The follow up assessment at month 6 was completed by 962 (71.2%) study participants. The results concerning the primary outcome showed a stronger decrease of addictive behaviors between baseline and follow up in the intervention group compared to the control group. In particular, significant effects were observed for at-risk drinking and problematic Internet use, while no significant effects were observed for tobacco/e-cigarette smoking and cannabis use. CONCLUSIONS: The majority of apprentices invited for program participation within vocational schools participated in the ready4life program for addiction prevention. The mobile app-based coaching was effective in reducing risk behaviors such as at-risk drinking and problematic Internet use in a group of adolescents who have an especially high risk of engaging in addictive activities.

A Mobile Phone-Based Life-Skills Training Program for Substance Use Prevention Among Adolescents: Cluster-Randomized Controlled Trial.

BACKGROUND: Life skills are abilities for adaptive and positive behavior that enable individuals to deal effectively with the demands and challenges of everyday life. Life-skills training programs conducted within the school curriculum are effective in preventing the onset and escalation of substance use among adolescents. However, their dissemination is impeded due to their large resource requirements. Life-skills training provided via mobile phones may provide a more economic and scalable approach. OBJECTIVE: The goal of this study was to test the appropriateness (ie, acceptance, use, and evaluation) and short-term efficacy of a mobile phone-based life-skills training program to prevent substance use among adolescents within a controlled trial. METHODS: The study design was a two-arm, parallel-group, cluster-randomized controlled trial with assessments at baseline and follow-up assessments after 6 and 18 months. This report includes outcomes measured up to the 6-month follow-up. The efficacy of the intervention was tested in comparison to an assessment-only control group. The automated intervention program SmartCoach included online feedback and individually tailored text messages provided over 22 weeks. The contents were based on social cognitive theory and addressed self-management skills, social skills, and substance use resistance skills. Linear mixed models and generalized linear mixed models, as well as logistic or linear regressions, were used to investigate changes between baseline and 6-month follow-up in the following outcomes: 30-day prevalence rates of problem drinking, tobacco use, and cannabis use as well as quantity of alcohol use, quantity of cigarettes smoked, cannabis use days, perceived stress, well-being, and social skills. RESULTS: A total of 1759 students from 89 Swiss secondary and upper secondary school classes were invited to participate in the study. Of these, 1473 (83.7%) students participated in the study; the mean age was 15.4 years (SD 1.0) and 55.2% (813/1473) were female. Follow-up assessments at 6 months were completed by 1233 (83.7%) study participants. On average, program participants responded to half (23.6 out of 50) of the prompted activities. Program evaluations underlined its appropriateness for the target group of secondary school students, with the majority rating the program as helpful and individually tailored. The results concerning the initial effectiveness of this program based on 6-month follow-up data are promising, with three of nine outcomes of the intention-to-treat analyses showing beneficial developments of statistical significance (ie, quantity of alcohol use, quantity of tobacco use, and perceived stress; P<.05) and another three outcomes (ie, problem drinking prevalence, cannabis use days, and social skills) showing beneficial developments of borderline significance (P<.10). CONCLUSIONS: The results showed good acceptance of this intervention program that could be easily and economically implemented in school classes. Initial results on program efficacy indicate that it might be effective in both preventing or reducing substance use and fostering life skills; however, data from the final 18-month follow-up assessments will be more conclusive. TRIAL REGISTRATION: ISRCTN Registry ISRCTN41347061; https://doi.org/10.1186/ISRCTN41347061.

CANreduce 2.0 Adherence-Focused Guidance for Internet Self-Help Among Cannabis Users: Three-Arm Randomized Controlled Trial.

BACKGROUND: Despite increasing demand for treatment among cannabis users in many countries, most users are not in treatment. Internet-based self-help offers an alternative for those hesitant to seek face-to-face therapy, though low effectiveness and adherence issues often arise. OBJECTIVE: Through adherence-focused guidance enhancement, we aimed to increase adherence to and the effectiveness of internet-based self-help among cannabis users. METHODS: From July 2016 to May 2019, cannabis users (n=775; male: 406/575, 70.6%, female: 169/575, 29.4%; age: mean 28.3 years) not in treatment were recruited from the general population and were randomly assigned to (1) an adherence-focused guidance enhancement internet-based self-help intervention with social presence, (2) a similar intervention with an impersonal service team, and (3) access to internet as usual. Controls who were placed on a waiting list for the full intervention after 3 months underwent an assessment and had access to internet as usual. The primary outcome measurement was cannabis-use days over the preceding 30 days. Secondary outcomes included cannabis-dependence severity, changes in common mental disorder symptoms, and intervention adherence. Differences between the study arms in primary and secondary continuous outcome variables at baseline, posttreatment, and follow-up were tested using pooled linear models. RESULTS: All groups exhibited reduced cannabis-use days after 3 months (social presence: -8.2 days; service team: -9.8 days; internet as usual: -4.2 days). The participants in the service team group (P=.01, d=.60) reported significantly fewer cannabis-use days than those in the internet as usual group; the reduction of cannabis use in the social presence group was not significant (P=.07, d=.40). There was no significant difference between the 2 intervention groups regarding cannabis-use reduction. The service team group also exhibited superior improvements in cannabis-use disorder, cannabis-dependence severity, and general anxiety symptoms after 3 months to those in the internet as usual group. CONCLUSIONS: The adherence-focused guidance enhancement internet-based self-help intervention with an impersonal service team significantly reduced cannabis use, cannabis-use disorder, dependence severity, and general anxiety symptoms. TRIAL REGISTRATION: ISRCTN Registry ISRCTN11086185; http://www.isrctn.com/ISRCTN11086185.

Stigmatizing attitudes of Swiss youth towards peers with mental disorders.

BACKGROUND: Previous research on public stigma towards people with mental disorders has mostly targeted adult samples and focused on depression, schizophrenia or mental disorders in general. Hence, the present study aimed to investigate predictors of stigmatizing attitudes towards different mental disorders (including less researched ones) in a representative sample of adolescents and young adults. METHODS: Data from the Swiss Youth Mental Health Literacy and Stigma Survey were used (analytical sample: n = 4,932). Each participant was randomly presented with one of five vignettes (depression; alcohol abuse; depression and alcohol abuse combined; schizophrenia; social anxiety). The structure of stigmatizing attitudes was assessed using confirmatory factor analysis. Regression models, implemented within a structural equation framework, were used to study predictors for the identified latent variables. RESULTS: A three-factor model for stigmatizing attitudes-consisting of 'dangerous/unpredictable', 'weak-no-sick', and 'social distance' factors-best fitted the data. Female gender was associated with less stigmatizing attitudes. Associations in opposite directions with different latent factors were found for educational and migration background. Exposure to mental disorders (being personally affected, personally having received professional help or knowing someone close who has received treatment for a mental disorder) was either not or was negatively associated with stigmatizing attitudes. In contrast, current mental health symptoms (heightened levels of psychological distress, problematic alcohol use) were generally not or were positively associated with stigmatizing attitudes. Even though the included predictors had some predictive value, the variance explained by the models was rather small (the adjusted R2 varied between 0.03 and 0.26). CONCLUSIONS: The current study indicates that contact with someone who has received treatment for a mental disorder might be an important component of programs aiming to decrease stigmatizing attitudes towards people with mental disorders, since this exposure variable predicted lower levels of stigmatizing attitudes. Furthermore, the findings suggest that target-group interventions for specific subgroups need to be considered, as the process leading to stigmatizing attitudes towards people with mental disorders appears to differ between specific sociodemographic subgroups.

e-INEBRIA Special Interest Group Roadmap for Best Practices for Research on Brief Digital Interventions for Problematic Alcohol and Illicit Drug Use.

There is great potential for scaling up the delivery of brief interventions for alcohol and illicit drug use, given the increasing coverage of mobile devices and technologies for digital interventions, including apps for smartphones and tablets. However, while the number of digital interventions is increasing rapidly, the involvement of brief-intervention researchers and the development of good practices has just begun. In 2018, the Special Interest Group on digital interventions of the International Network on Brief Interventions for Alcohol & Other Drugs (e-INEBRIA SIG) initiated a conversation regarding possible avenues of future research, which subsequently became a roadmap for digital interventions. This roadmap consists of points considered relevant for future research, ongoing technological developments, and their implementation across a continuum of prevention and care. Moreover, it outlines starting points for the diversification of brief digital interventions, as well as next steps for quality improvement and implementation in public health and clinical practice. The roadmap of the e-INEBRIA SIG on digital interventions is a starting point that indicates relevant next steps and provides orientation for researchers and interested practitioners with regard to the ambiguous literature and the complexity of current digital interventions.

Assessment of the Efficacy of a Mobile Phone-Delivered Just-in-Time Planning Intervention to Reduce Alcohol Use in Adolescents: Randomized Controlled Crossover Trial.

BACKGROUND: Interventions to reduce alcohol use typically include several elements, such as information on the risks of alcohol consumption, planning for sensible drinking, and training of protective behavioral strategies. However, the effectiveness of these individual intervention elements within comprehensive programs has not been addressed so far, but it could provide valuable insights for the development of future interventions. Just-in-time interventions provided via mobile devices are intended to help people make healthy decisions in the moment and thus could influence health behavior. OBJECTIVE: The aim of this study was to test the proximal effects of a mobile phone-delivered, just-in-time planning intervention to reduce alcohol use in adolescents who reported recent binge drinking. The efficacy of this individual intervention element was tested within a comprehensive intervention program to reduce problem drinking in adolescents. METHODS: The study had an AB/BA crossover design, in which participants were randomly allocated to (1) a group receiving the planning intervention (A) in period 1 and assessment only (B) in period 2 or (2) a group receiving assessment only (B) in period 1 and the planning intervention (A) in period 2. The planning intervention included a text message to choose one of two predetermined if-then plans to practice sensible drinking with friends or when going out and a prompt to visualize the chosen plan. There was a washout period of at least 1 week between period 1 and period 2. RESULTS: Out of 633 program participants who recently binge drank, 136 (21.5%) were receptive in both periods of time and provided data on the proximal outcome, which was the number of alcoholic drinks consumed with friends or when going out. After the planning intervention, the number of alcoholic drinks consumed was approximately one standard drink lower compared with the finding without the intervention (P=.01). CONCLUSIONS: A mobile phone-delivered, just-in-time, if-then planning intervention to practice sensible drinking with friends or when going out is effective in reducing alcohol consumption among adolescents who report recent binge drinking. Based on the relatively low percentage of participants with self-reported receptivity for the planning intervention, measures to increase the population impact of similar planning interventions should be implemented and tested in future trials. TRIAL REGISTRATION: ISRCTN Registry ISRCTN52150713; http://www.isrctn.com/ISRCTN52150713.

Design of a Guided Internet- and Mobile-Based Intervention for Internet Use Disorder-Study Protocol for a Two-Armed Randomized Controlled Trial.

Context: Internet Use Disorder (IUD), characterized as the inability to control one's internet use, is emerging as an increasing societal concern as it is associated with reduced quality of life and mental health comorbidities. Evidence-based treatment options are, however, scarce due to the novelty of the diagnosis. Internet- and mobile-based interventions may be an effective means to deliver psychological treatment to individuals with IUD as they address individuals affected in their online setting. The aim of the study is to evaluate the efficacy of a newly developed, guided internet- and mobile-based intervention for IUD. Methods: In a two-armed randomized controlled trial (N = 130), individuals showing problematic internet use patterns (Internet Addiction Test ≥ 49) will be randomly allocated to the internet- and mobile-based intervention or a waiting control group. Assessments will take place at baseline, 7 weeks, 6- and 12 months after randomization. The primary outcome is internet addiction symptom severity (IAT) at 7 weeks. Secondary outcomes include quality of life, depressive symptoms, anxiety, and other psychosocial variables associated with IUD. Intervention: The intervention consists of seven sessions: Goal setting and motivational interviewing, impulse control, problem solving, cognitive restructuring, self-worth, relapse prevention, and a booster session. Participants are supported by an eCoach who provides individual feedback after completion of each session. Participants can choose between several elective sessions based on individual need. Conclusions: This is the first study to evaluate an internet- and mobile-based intervention for IUD, which could be a promising first step to reduce individuals' disease burden. Trial Registration: DRKS00015314. The study is currently ongoing. First participants were enrolled in the study on September 14th 2018. Recruitment will continue approximately through March 2020.

Problematic smartphone use in young Swiss men: Its association with problematic substance use and risk factors derived from the pathway model.

BACKGROUND AND AIMS: This study aimed to examine associations between risk factors suggested in the pathway model proposed by Billieux et al., demographic and substance use variables, and problematic smartphone use (PSU). METHODS: The analytical sample consisted of 5,096 Swiss men (mean age = 25.5 years, SD = 1.26). Multiple linear regression analyses were conducted with PSU as dependent and the following as independent variables: (a) Billieux's pathway model variables (depression, social anxiety, ADHD, aggression-hostility, and sensation seeking); (b) substance use variables [alcohol: at-risk risky single-occasion drinking (RSOD); at-risk volume drinking; tobacco use: daily smoking; illicit drug use: more than weekly cannabis use; having used at least one other illicit drug besides cannabis over the preceding 12 months]; and (c) sociodemographic variables (age, language region, and education). RESULTS: All pathway-model variables except sensation seeking were significant predictors of PSU, especially symptoms of social anxiety (ß = 0.196) and ADHD (ß = 0.184). At-risk RSOD was positively (ß = 0.071) associated with PSU, whereas both frequent cannabis use (ß = -0.060) and daily cigarette smoking (ß = -0.035) were negatively associated with PSU. Higher-achieved educational levels and being from the German-speaking part of Switzerland predicted PSU. DISCUSSION AND CONCLUSIONS: The findings of this study can be used to develop tailored interventional programs that address the co-occurrence of certain risky behaviors (e.g., at-risk RSOD and PSU) and target individuals who might be particularly prone to PSU. Such interventions would need to ensure that addressing one problem (e.g., decreasing PSU) does not lead to some other compensatory behavior (e.g., frequent cigarette smoking).

Efficacy of a web-based intervention with and without guidance for employees with risky drinking: results of a three-arm randomized controlled trial.

AIMS: To test the efficacy of a web-based alcohol intervention with and without guidance. DESIGN: Three parallel groups with primary end-point after 6 weeks. SETTING: Open recruitment in the German working population. PARTICIPANTS: Adults (178 males/256 females, mean age 47 years) consuming at least 21/14 weekly standard units of alcohol (SUA) and scoring ≥ 8/6 on the Alcohol Use Disorders Identification Test. INTERVENTION: Five web-based modules including personalized normative feedback, motivational interviewing, goal setting, problem-solving and emotion regulation during 5 weeks. One intervention group received an unguided self-help version (n=146) and the second received additional adherence-focused guidance by eCoaches (n=144). Controls were on a waiting list with full access to usual care (n=144). MEASUREMENTS: Primary outcome was weekly consumed SUA after 6 weeks. SUA after 6 months was examined as secondary outcome, next to numbers of participants drinking within the low-risk range, and general and work-specific mental health measures. FINDINGS: All groups showed reductions of mean weekly SUA after 6 weeks (unguided: -8.0; guided: -8.5; control: -3.2). There was no significant difference between the unguided and guided intervention (P=0.324). Participants in the combined intervention group reported significantly fewer SUA than controls [B=-4.85, 95% confidence interval (CI)=-7.02 to -2.68, P < 0.001]. The intervention groups also showed significant reductions in SUA consumption after 6 months (B=-5.72, 95% CI=-7.71 to -3.73, P < 0.001) and improvements regarding general and work-related mental health outcomes after 6 weeks and 6 months. CONCLUSIONS: A web-based alcohol intervention, administered with or without personal guidance, significantly reduced mean weekly alcohol consumption and improved mental health and work-related outcomes in the German working population.

Evaluating the (cost-)effectiveness of guided and unguided Internet-based self-help for problematic alcohol use in employees--a three arm randomized controlled trial.

BACKGROUND: Problematic alcohol consumption is associated with a high disease burden for affected individuals and has a detrimental impact on companies and society due to direct and indirect health costs. This protocol describes a study design to evaluate the (cost)-effectiveness of a guided and unguided Internet-based self-help intervention for employees called "GET.ON Clever weniger trinken" (be smart - drink less) compared to a waiting list control group. METHODS: In a three-arm randomized controlled trial, 528 German adults who are currently members of the workforce will be recruited by occupational health departments of major health insurance companies. Employees aged 18 and older displaying problematic drinking patterns (>21/14 drinks per week and an AUDIT score > 8/6 for men/women) will be randomly assigned to one of three following study conditions: 1. unguided web-based self-help for problematic drinking, 2. adherence-focused guided self-help, and 3. waiting list control. Self-report data will be collected at baseline (T1), 6 weeks (T2), and 6 months (T3) after randomization. The primary outcome will be the reduction of alcohol standard units during the 7 days prior to T2, using the Timeline Followback method. Cost-effectiveness analyses to determine direct and indirect costs will be conducted from the perspectives of employers and the society. Data will be analyzed on an intention-to-treat basis and per protocol. DISCUSSION: There is a need to identify effective low-threshold solutions to improve ill-health and reduce the negative economic consequences due to problematic alcohol drinking in workforces. If the proposed web-based intervention proves both to be efficacious and cost-effective, it may be a useful tool to increase utilization rates of interventions for problematic drinking in occupational settings. TRIAL REGISTRATION: German Register of Clinical Studies (DRKS): DRKS00006105 , date of registration: 2014-07-07.

Effectiveness of different Web-based interventions to prepare co-smokers of cigarettes and cannabis for double cessation: a three-arm randomized controlled trial.

BACKGROUND: The relationship between tobacco and cannabis use is strong. When co-smokers try to quit only one substance, this relationship often leads to a substitution effect, that is, the increased use of the remaining substance. Stopping the use of both substances simultaneously is therefore a reasonable strategy, but co-smokers rarely report feeling ready for simultaneous cessation. Thus, the question of how co-smokers can be motivated to attempt a simultaneous cessation has arisen. To reach as many co-smokers as possible, we developed brief Web-based interventions aimed at enhancing the readiness to simultaneously quit tobacco and cannabis use. OBJECTIVE: Our aim was to analyze the efficacy of three different Web-based interventions designed to enhance co-smokers' readiness to stop tobacco and cannabis use simultaneously. METHODS: Within a randomized trial, three brief Web-based and fully automated interventions were compared. The first intervention combined the assessment of cigarette dependence and problematic cannabis use with personalized, normative feedback. The second intervention was based on principles of motivational interviewing. As an active psychoeducational control group, the third intervention merely provided information on tobacco, cannabis, and the co-use of the two substances. The readiness to quit tobacco and cannabis simultaneously was measured before and after the intervention (both online) and 8 weeks later (online or over the phone). Secondary outcomes included the frequency of cigarette and cannabis use, as measured at baseline and after 8 weeks. RESULTS: A total of 2467 website users were assessed for eligibility based on their self-reported tobacco and cannabis co-use, and 325 participants were ultimately randomized and analyzed. For the post-intervention assessment, generalized estimating equations revealed a significant increase in the readiness to quit tobacco and cannabis in the total sample (B=.33, 95% CI 0.10-0.56, P=.006). However, this effect was not significant for the comparison between baseline and the 8-week follow-up assessment (P=.69). Furthermore, no differential effects between the interventions were found, nor were any significant intervention or time effects found on the frequency of tobacco or cannabis use. CONCLUSIONS: In the new field of dual interventions for co-smokers of tobacco and cannabis, Web-based interventions can increase the short-term readiness to quit tobacco and cannabis simultaneously. The studied personalized techniques were no more effective than was psychoeducation. The analyzed brief interventions did not change the secondary outcomes, that is the frequency of tobacco and cannabis use. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number (ISRCTN): 56326375; http://www.isrctn.com/ISRCTN56326375 (Archived by WebCite at http://www.webcitation.org/6UUWBh8u0).