An interventional study of ABC-teen and ParentWeb in Mental Health Issue, Mental Disorder and Adolescent Behavior, sponsored by Karolinska Institutet. Completed at 58 sites in Sweden. Open to participants aged 13 Years to 19 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-23.
Sponsored by Karolinska Institutet · Not applicable, Interventional, and Prevention
Group-based and internet-delivered parenting programs may help parents improve their communication and relationships with their children. However, relatively little is known about how well such programs work for parents of adolescents, because most previous studies have focused on younger children or on families selected because of elevated risk.
This study evaluated two universal preventive parenting programs for parents of adolescents: the group-based ABC-Teen program and the internet-delivered ParentWeb program. Both programs were developed in Sweden and aim to promote adolescent well-being by strengthening parenting practices and parent-adolescent relationships and reducing negative communication.
Families were randomized to ABC-Teen, ParentWeb, or a waitlist control condition. The sole primary outcome was parent-reported adolescent mental health problems, measured using the Strengths and Difficulties Questionnaire Total Difficulties score. Secondary outcomes included parental mental health and stress, parenting behaviors and parental self-efficacy, parent-adolescent and family relationships, adolescent school adjustment and substance use, and outcomes reported by participants in an optional adolescent survey.
Parent and adolescent assessments were conducted at baseline, 4 months, and 12 months. After completion of the 4-month assessment, families assigned to the waitlist were offered their choice of ABC-Teen or ParentWeb. Consequently, comparisons with the waitlist were restricted to the period from baseline to 4 months, whereas longer-term analyses compared ABC-Teen with ParentWeb.
BACKGROUND:
Despite the development of psychological treatments in recent decades, mental health disorders remain a main cause of disease, functional impairments, and deaths of adolescents across the world. UNICEF estimated that globally, over 13 percent of adolescents 10-19 live with a mental disorder. Moreover, suicide is the fifth most common cause of death for adolescents in the same age-span and the fourth most prevalent cause for adolescents 15-19 years old. Reports also show that youth mental illness have increased in recent years. Psychological treatments seems not enough to combat this negative development; preventive efforts are needed.
Family experiences can be a target of prevention given the strong impact on young peoples' current and future mental health. The quality of the parent-child relationship impacts health quality throughout life. Also, adverse experiences related to family and parenting dysfunction is one of the main predictors of mental ill-health. While adolescence is a period of increased independence, parents remain one of the most important people in the young person's life. A link between parenting factors during adolescence and anxiety and depression, which constitutes 40% of diagnosed adolescent mental disorders, is established. Parenting factors linked to depression and anxiety include low warmth, inter-parental conflict, over-involvement, and aversiveness.
Decades of research support the health benefits of parent training programs that help parents interact and communicate with their children, including face-to-face programs delivered in groups and internet-based programs. However, most studies have concerned children below 13 years of age. Given the impact of parenting factors during adolescence on mental health, it is important to investigate how parenting programs work for parents of adolescents.
Parenting programs on different prevention levels are needed to maximize the benefit on public health. However, most studies have concerned indicated/selected prevention or treatments. Outcomes have mostly concerned symptom reduction. To prevent health problems at a population scale, more studies are needed of how parenting programs benefit the general population (i.e., universal prevention). The general population includes those who do not presently experience clinical problems, but where future issues may be prevented through strengthening health-promoting factors (e.g., family relationships).
PURPOSE AND RESEARCH QUESTIONS:
The aim of this study is to assess the effectiveness of two universal preventive parenting programs for teenagers: ABC-teen and ParentWeb. A version of the ABC program for children 3-12 years old has been evaluated in a randomized controlled trial, but so far no study has investigated ABC-teen. Likewise, a longer version of the ParentWeb targeting a selected group of parents with elevated levels of conflict with their adolescents has been published, but no study on the universal version of ParentWeb. The effects of the programs will be evaluated both in comparison to each other and to a Wait-List control. Both programs aim to strengthen the parent-adolescent relationship and reduce negative communication.
To what extent do the parents experience participation in the programs' as feasible and satisfying?
Research question 1-6 will be reported in the main paper from the project, while the following research questions will be reported in following papers.
METHOD:
Participants:
The sample consisted of 1247 families (1327 parents and 471 adolescents) from the general population, from 58 sites in 52 municipalities across Sweden. The participants were recruited through local advertisements in schools or online municipality channels. Parents who were interested were referred to a website with additional information and a consent form. All members in a family (parents and adolescents) were invited to contribute to the data collection in the study (questionnaires).
Design:
The study is a multi-site randomized controlled trial. Parents were randomized to ABC-teen, ParentWeb or a 4 months Wait-List control. After recruitment, participants responded to baseline measurements and were subsequently randomized to one of the three study conditions. The randomization was conducted centrally by the researchers, but with separate randomization list for each site (generated at randomize.org). The researchers then informed a local coordinator at the site about participants' allocation. Parents and adolescents who were included at baseline were invited to answer follow-up questionnaires after 4 and 12 months. The wait-list control group parents were invited to participate in either ABC-teen or ParentWeb (their choice) after 4 months. Thus, at the 12 month follow-up, analyses of program effects will be restricted to comparisons between the programs.
Sample size calculation:
As the effects of universal interventions are generally small, a relatively large study group was required for adequate statistical power, also considering that drop-out can be substantial in multi-site studies. For a statistical power of 80%, 200 participating families will be needed to detect small differences in effect size (Cohen's d = .20) with alpha = 0.05. Since the randomization was unbalanced (2-1-1 in ABC-teen, ParentWeb, and wait list), an additional 200 families had to be recruited to reach at least 200 in each condition (i.e., 400 in ABC-teen, 200 in ParentWeb, and 200 in the wait list). This means that a total of 800 families with complete data were needed for the study. To account for dropout, an additional 447 families were recruited. Actual n:s in each condition at each measurement point were as follows at the completion of data collection: ABC-teen - 669 (baseline), 520 (4 month), 458 (12 month); ParentWeb - 297 (baseline), 209 (4 month), 168 (12 month); Wait list - 281 (baseline), 210 (4 month).
Statistical analyses:
Linear Mixed Modeling (LMM) will be used for analyzing the effects of the programs (questions 1-5) in two steps: First, effects at 4 month will be analyzed comparing each of the program to the wait list control. Second, the two programs will be compared to each other at 4 and 12 month. For questions 6, t-tests will be conducted to investigate mean differences between the two program conditions. For question 7, LMM-analyses will be conducted with predictors and moderators entered into the equations, to test if they have (differential) effects on the slope of adolescent mental health and parenting variables from baseline to 12 month follow-up. For question 8, two different health economic analyses will be conducted - one analyzing the cost of health gains in terms of quality of life (by mapping scores from the SDQ to preference-based utility values), and another analyzing the cost of health gains in terms of reduced mental illness (recovered cases). All analyses will be conducted according to Intention-to-treat (primary results), as well as per protocol (sensitivity).
1,740 studies on the registry are indexed under Mental Disorders; 348 are open to participants now.
This study's enrollment of 1,247 is above the median of 100 across 1,301 interventional studies indexed under Mental Disorders.
Browse Mental Disorders studies →Karolinska Institutet is the lead sponsor of 1,148 studies on the registry; 276 are open to participants now.
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Exclusion Criteria:
The ABC-teen is a universal parenting program where two trained leaders meet parents meet in groups (10-15 parents) at four occasions (2.5 hours each). One or two follow-up meetings are also offered. The themes that are covered during the meetings include: spending time together, communication, parental stress management and emotion regulation, and problem solving/conflict resolution.
Behavioral: ABC-teen
ParentWeb is an online-based program where parents individually work with material online (text, images, clips, quizzes), while they receive support from a parent guide through asynchronous text messages. The program includes four main modules that are expected to be covered in eight weeks. The themes of the modules include: spending time together, communication, problem solving/conflict resolution, and keeping in touch while letting go of control.
Behavioral: ParentWeb
The parents will be on a six months wait-list control group.
See above
See above
Parent-reported Strengths and Difficulties Questionnaire Total Difficulties score
Parent-reported measure of adolescent mental health problems. The Total Difficulties score is the sum of the Emotional Symptoms, Conduct Problems, Hyperactivity/Inattention, and Peer Problems subscales. Scores range from 0 to 40, with higher scores indicating greater difficulties. This was the sole primary outcome.
Time frame: Baseline and 4 months (primary comparison); additionally assessed at 12 months in the two intervention groups.
Conflict scale
Measures the relationship between the parent and the adolescent. The scale measure the frequency of everyday conflicts between the parent and the adolescent. A number of typical conflicts are listed and the participants are asked to rate how frequently they have occurred on a likert scale from 0 (never) to 3 (often). Rated by parents and adolescents.
Time frame: Pre (0 month), 4 months, 12 months
Adult Child Relationship Scale (ACRS)
Measures the relationship between the parent and the adolescent (specifically expressions of warmth and closeness in the relationship). It includes 6 items (e.g., "If my teenager is upset, he/she turns to me for support") which are rated on a likert scale from 0 (I do not agree at all) to 4 (I agree completely). Rated by parents and adolescents.
Time frame: Pre (0 month), 4 months, 12 months
General Anxiety Disorder Scale (GAD-7)
Measures parental mental health (specifically anxiety). Rated by parents. The range of the scale is 0 to 21, where higher scores indicate more symptoms of anxiety.
Time frame: Pre (0 month), 4 months, 12 months
Parental stress scale (PSS)
Measures parental mental health (specifically parental stress). Rated by parents. The range of the scale is 0 to 32 points, where higher scores indicate more stress.
Time frame: Pre (0 month), 4 months, 12 months
Patient Health Questionnaire (PHQ-9)
Measures parental mental health (specifically depression). Rated by parents. The range of the scale is 0 to 27 points, where higher scores indicates more depressive symptoms.
Time frame: Pre (0 month), 4 months, 12 months
Adolescents' openness scale
Measures the relationship between the parent and the adolescent (specifically teenagers openness with their parents). It includes 6 items (e.g., "Does your teenager tell you which peers he/she has hanged out with if he/she has been out?"), which are rated on a likert scale from 0 (never) to 4 (almost always). Rated by parents and adolescents.
Time frame: Pre (0 month), 4 months, 12 months
Brief Family Relationship Scale
Measures the relationship in the family as a whole. It includes 15 items (e.g., "In our family we really get along well with each other."), which are rated on a likert scale from 1 (Do not agree at all) to 20 (Agrees completely). Rated by parents.
Time frame: Pre (0 month), 4 months, 12 months
Positive and Negative Parenting Behaviors
Measures parent behaviors. The scale consists of 4 items that has been used in a large scale dissemination study of ABC for children 3-12 years (e.g., "How often have you been spending time or doing something nice together with your teenager the past two weeks?" and "How often have you been nagging on your teenager the past two weeks?"). The items are rated on a likert scale from 1 (Never) to 7 (Several times a day). Rated by parents.
Time frame: Pre (0 month), 4 months, 12 months
Me as a Parent
Measures parental self-efficacy. The scale consists of 16 items (e.g., "I am satisfied with the way I am able to emotionally support my teenager"), which are rated on a likert scale from 0 (Do not agree at all) to 4 (Agree to a high extent). Rated by parents.
Time frame: Pre (0 month), 4 months, 12 months
Conflict Resolution Efficacy
Measures parental self-efficacy (specifically self-efficacy regarding management of conflicts). The scale is connected to the Conflict Scale described above. For each type of conflict that at least has occurred to some extent during the past two weeks (e.g. "Conflicts regarding screen-time"), the following sub-question appears: "How did you manage to handle those conflicts?". The sub-questions are rated on a likert scale from 1 (Badly) to 10 (Good). Rated by parents.
Time frame: Pre (0 month), 4 months, 12 months
School Adjustment Scale
Measures the school adjustment. The scale consists of four items from an annual survey used nationally by school districts in Sweden (e.g., "I find the school work interesting"). Each item is rated on a likert scale from 0 (I do not agree at all) to 3 (I agree completely). Rated by parents and adolescents.
Time frame: Pre (0 month), 4 months, 12 months
Stockholmsenkaten
The scale consists of 9 items from a yearly school survey used in the school district of Stockholm to measures adolescent use of tobacco, alcohol and drugs. The data from the measure can both used as dichotomous outcomes (Ever used tobacco/alcohol/drugs? YES/NO), but also as a continuous outcome since the frequency of use (if any) also is measured. When used as a continuous outcome, the scale includes the three sub scales: Tobacco (range 0-6 points), Alcohol (range 0-25 points), and Drugs (range 0-12 points). For all sub scales, higher values indicate higher frequency of use.
Time frame: Pre (0 month), 4 months, 12 months
Satisfaction Questionnaire
Measures parents satisfaction with participation in the parenting programs. The scale consists of four items concerning the extent to which the parents experience that the program has led to improvements, has helped them in general, and how likely it is that they would recommend it to a friend. Each item is rated on a likert scale from 0 (Not at all) to 3 (Very much). Rated by parents.
Time frame: At 4- and 12 month follow-ups.
Attendance and engagement measures
Measures attendance and engagement, which indirectly indicates feasibility. Questions regarding attendance/completion of each meeting/module and regarding homework completion, for both the responding parent as well as co-parents. Rated by parents (and staff).
Time frame: At 4- and 12 month follow-ups.
Adolescent-reported Strengths and Difficulties Questionnaire Total Difficulties score
Adolescent-reported measure of mental health problems. The Total Difficulties score is calculated as the sum of the Emotional Symptoms, Conduct Problems, Hyperactivity/Inattention, and Peer Problems subscales. Scores range from 0 to 40, with higher scores indicating greater difficulties. This was a secondary outcome assessed in the optional adolescent survey.
Time frame: Pre (0 month), 4 months, 12 months
Demographics
Questions to assess family background and living conditions. Not outcome measures, but to be used in analyses of predictors and moderators.
Time frame: Pre (0 month)
Organizational and therapist factors
Questions about organizational and personnel factors (e.g. group leader background). Not outcome measures, but to be used in analyses of predictors and moderators. Rated by group leaders.
Time frame: Pre (0 month)
Plan to share: No
Ran from Dec 2021 to primary completion in Jan 2024, 25 months.
Of 666 non-industry interventional studies with no phase under Mental Disorders, half reached primary completion within 29 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 45. This study's 25 months is below that.
Counting every sponsor, half of 680 studies reached it within 29 months; a quarter within 13 and three quarters within 45.
Mental Disorders covers many different conditions, not one, so the studies compared here vary widely. Read these figures as a rough guide.
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