Parenting Support: Mediation Pathways for Reduced Substance Use Among Parents and Their Children: A Randomized Controlled Trial


 Background: Substance use is a major public health concern worldwide. Alcohol and drug use have risen over recent decades in many low and middle-income countries, with South Africa among the highest globally.Despite effectiveness of family-based interventions on reducing substance use among adolescents, less is known about the effectiveness of family-based programs on substance use among parents and caregivers, in particular, among families in low- and middle-income countries (LMIC).This study investigated mediators of change in a parenting programme (Parenting for Lifelong Health -PLH) on reduction of substance use among parents and their children through three potential mediators: parental depression, parenting stress and family poverty. In addition, the study examined the correlation between parental substance use and adolescent substance use.Methods: The current study draws on a pragmatic cluster randomized controlled trial design; the total sample comprised 552 parents\caregiver and adolescent dyads (parents\caregivers M = 49.37; SD = 14.69 and adolescents M = 13.84; SD = 2.38) who were recruited from 40 communities in South Africa’s Eastern Cape. Participants completed a structured confidential self-report questionnaire, at baseline and follow-up test (5–9 months following the intervention). Structural equation modeling (SEM) was conducted to investigate direct and indirect effects. Results: Mediation analysis indicated that PLH intervention impact on parental substance use reduction among parents ran through one indirect pathway: Improvement in parental mental health (reduction in parental depression levels). There were no pathways from PLH intervention to parental substance use through parenting stress or family poverty. Furthermore, findings showed a significant positive correlation between parental substance use and adolescents' substance use.Conclusions: The findings of the study highlight the fact that PLH parenting intervention has a significant effect on secondary outcomes, including substance use and depression among parents\caregivers in LMIC. These findings emphasize the need for creating supportive environments and systems for parents who suffer from emotional strain and mental health problems, in particular among families in adversity. Supporting parental mental health as part of a parenting programme serves as a significant pathway for reducing substance use among parents and their children.Trial registration: Pan-African Clinical Trials Registry PACTR201507001119966. Registered on 27 April 2015. It can be found by searching for the key word ‘Sinovuyo’ on their website or via the following link:http://www.pactr.org/ATMWeb/appmanager/atm/atmregistry_nfpb=true&_windowLabel=BasicSearchUpdateController_1&BasicSearchUpdateController_1_actionOverride=%2Fpageflows%2Ftrial%2FbasicSearchUpdate%2FviewTrail&BasicSearchUpdateController_1id=1119


_1id=1119
Background Substance use is a major public health concern worldwide [1,2]. Previous studies have shown that substance use among adults and adolescents (including problematic alcohol, tobacco and drug use) is associated with physical, mental and social problems [3,4]. Empirical studies have found that problematic alcohol use among adults plays a role in involvement in risky behaviors such as sexual behaviors [5].
As substance use is in uenced by familial risk factors, prevention programs that change family dynamics were found to be the most effective interventions [8]. A review of causal models of substance use and evidence-based practices in high-income countries have found family therapy interventions effective in reducing substance use among adolescents by addressing familial processes and dynamics [9]. However, less is known about the effectiveness of parenting-based programs on substance use among parents\caregivers, particularly within LMIC.
Findings of a randomized controlled trial conducted in South Africa have shown that the Parenting for Lifelong Health programme for adolescents and their parents (Sinovuyo Teen PLH) was associated with lower levels of substance use among parents\caregivers and adolescents [10]. The current study aims at investigating the mechanism of substance use reduction among parents\caregivers and their children by addressing potential mediators which could explain the reduction of substance use among parents\caregivers and their children who participated in the PLH intervention.
An understanding of factors related to substance use will assist our understanding of the mechanism of reducing substance use among parents\caregivers and adolescents. Therefore, the current study aims to investigate the impact of the PLH programme on substance use reduction among parents and adolescents through three potential mediators: parenting stress, parental depression and family poverty.
Previous studies have found a signi cant positive relationship between depressed mood and substance and alcohol use among adults [11][12][13]. Furthermore, a growing body of evidence highlights that substance use and heavy consumption of alcohol among adults has been associated with stressful life experiences ,as many may tend to consume excessive alcohol as act of coping with negative feelings [14,15].
Regarding the effect of poverty on substance use, there is mixed support for the claimed association between economic status and increased substance use. Several studies in HIC have shown that high socio-economic status is signi cantly and positively correlated with substance use among young adults [16]. This nding does not concur with other studies which have shown that low socio-economic populations suffer from greater levels of substance use [17,18].
Empirical research evidence suggests that parental substance use (including drinking problem and drug use) can directly affect the substance use of their children [19,20], and that children of parents with alcohol or drug use face a higher risk of drug involvement than others [21]. For example, if youth are aware of, or witness, their parent's use, a modeling effect might occur. Furthermore, parental substance use may increase the availability of that substance to their adolescent [22,23].
We can understand this approach based on social learning theories [24] of human development that suggest that human behaviors are learned within a social context and are in uenced by bonding with primary source of socialization, such as the family system. Theorists assert that adolescence is a particularly crucial time for learning norms at the highest level [25]. In addition, substance use negatively affects parental skills, and it can compromise parents' ability to be consistent, warm and emotionally responsive to their children [26,27]. Therefore, lack of parental involvement during adolescence could be a risk factor for adolescents' involvement in substance use.
The current study investigates the mechanism of a parenting programme (PLH) on reduction of substance among parents\caregivers and their children through three potential mediators: parenting stress, parental depression and family poverty. Based on the model shown in Fig. 1, we hypothesized that: (1) PLH intervention would reduce substance use among parents\caregivers and adolescents, (2) PLH intervention would reduce parenting stress, parental depression and family poverty, (3) parenting stress, parental depression and family poverty would mediate the association between PLH intervention and reduction of substance use among parents\caregivers and children, and (4) substance use among parents\caregivers would predict substance use among their children.

Study design and sample
In this pragmatic cluster randomized controlled trial, the total sample compromised 552 dyads of adolescents and their parents\caregivers (parents\caregivers M = 49.37; SD = 14.69 and adolescents M = 13.84; SD = 2.38) who were recruited from 40 communities (located in 34 rural villages and three large peri-urban townships) in South Africa's Eastern Cape. Due to high levels of orphaning and fostering in South Africa, there were no requirements for a biological relationship between adolescent and primary caregiver but they had to reside in the same dwelling for at least four nights per week. Further information about the study design and sample and inclusion, exclusion criteria is available in Cluver et al. [10]. Randomization was strati ed by urban location and conducted after baseline using a random number generator by an independent, blinded statistician (CL). Complete randomization within strata used a ratio of 1:1 intervention: control. The sample included 270 families in the intervention arm and 282 families in the control arm (M = 14 families per cluster, SD = 1.9). Blinding of participants and program providers was not feasible for parenting programs.
Ethical approval was given by the University of Oxford (SSD/CUREC2/11-40), University of Cape Town (PSY2014-001), and government Departments of Social Development and Education.

Procedure and data collection
Parents\caregivers and adolescents completed a structured self-report questionnaire at three points in time: pre-test (Baseline), 1 month post-intervention (with a limited sub-set of items) and 5-9 months postintervention. The analyses of the current study were conducted based on the data at baseline and followup tests.

Intervention group
Dyads (parent\caregiver and adolescent) in the intervention group received a 14-session parenting programme called "Parenting for Lifelong Health/Sinovuyo Teen". Each session lasted for 1-1:30 hours a week. All sessions took place in public and community places such as churches, community halls, schools and under trees.
Based on Social Learning Theory [28], the programme involves parenting principles, such as praising each other, managing anger and stress, joint problem-solving, non-violent discipline, rules and routines, keeping adolescents safe in the community, and responding to crises. In addition, the programme includes economic strengthening components of family budgeting and saving sessions. Sessions included songs, collaborative problem-solving techniques (not didactic methods) and traditional stories, role-play, modelling and stress reduction activities. The programme was designed for low-resource settings with no technology (such as video) or literacy requirements.
Participants were encouraged to engage in home practice in the week following each session. For participants unable to attend sessions due to illness or disability, catch-up meetings were arranged to give brief session content at home or in the hospital. A simple lunch was included at the beginning of each session as many participants found di culty in concentrating due to hunger. The programme was delivered by local community members, who were trained by a local NGO, Clowns Without Borders South Africa, and supported through weekly supervision.

Control group
Dyads in the control group received a one session ( ve hours) of hygiene programme called "SinoSoap". This programme was implemented by the NGO "Clown without Borders" in South Africa, and involved drama-based skills-building on safe water conservation and hand washing for children. The session was delivered through performance and activities. All children received a soap which -when used -had a small toy inside.

Measurements
Parents\caregivers and adolescents completed self-report questionnaires, using tablets at baseline, 1 month post-intervention and 5-9 months following the intervention. All questionnaires were pre-piloted with local adolescents and parents\caregivers. All measurements were translated into isiXhosa, one of the 11 o cial languages spoken in South Africa, and back-translated.
Alcohol and substance use among parents\caregivers was assessed by using the adapted version of the WHO Alcohol Use Disorders Identi cation Test (AUDIT) [29] and the WHO Global School-based Health Survey. This variable was reported by parents\caregivers (4 items; α = .529; e.g., "In the past month, have you had a drink?"; "Did you take any drugs to help you relax?"). Responses were: 0 = No and 1 = Yes. One overall score was derived by computing the sum of the items.
Alcohol and substance use among adolescents was measured by using three items from the Child Behavior Checklist Scale [30]. This variable was reported by adolescents (3 items; α = .547; e.g., "During the past month, I drank alcohol without the permission of my caregivers' approval"; "I smoke cigarettes"; "I use drugs like dagga (marijuana) or other drugs"). Responses ranged from 0 = Not true to 2 = Very true.
Parenting stress was measured using 18 items (α = .770; e.g., "I am happy in my role as a parent"; "Caring for my children sometimes takes more time and energy than I have to give") from the Parental Stress Scale [31]. Items were measured on a ve-point Likert type scale, ranging from 0 (Strongly disagree) to 4 (Strongly agree). One overall score was derived by computing the sum of the items.
Parental depression was assessed by using 20 items (α = .876; e.g., "I felt very sad even with help from my family and friends"; "I didn't feel like eating"; "My appetite was poor") from the Centre for Epidemiological Studies Depression Scale [32]. Responses ranged from 0 (Not at all) to 4 (Less than even day). One overall score was derived by computing the sum of the items. Items were measured on a vepoint Likert type scale, ranging from 0 (Strongly disagree) to 4 (Strongly agree).
Family poverty was measured as monthly consistent access to necessities including food, electricity, communication, and transport [33]. This variable was assessed by using 9 items (α = .683; e.g., "Afford 3 meals a day"; "Afford the costs of the school"; "Afford enough warm clothes"). Responses were: 0 = No and 1 = Yes. One overall score was derived by computing the sum of the items.
All variables were measured at baseline and 5-9 months follow-up after the intervention was completed.

Data analyses
Analyses used intention-to-treat (ITT) for all clusters and families irrespective of intervention uptake and included families who were no longer living together at follow-up (n = 53). Independent sample t-tests were conducted to compare means of outcomes and mediator differences at baseline and follow-up between intervention and control groups.
A linear Structural Equation Modeling (SEM) was used with AMOS21 statistics program. The SEM procedure combined measurement modeling (Con rmatory Factor Analyses -CFA) and structural equation modeling. Items that were theoretically and empirically perceived as describing the variable were used in the measurement model.
Goodness of t for the nal model was assessed using the Comparative Fit Index (CFI) and the Root Mean Standard Error of Approximation (RMSEA). We also report χ2 t statistics but acknowledge that the test is in ated by sample size of the study.

Results
Descriptive statistics T-test results for baseline and follow-up outcomes and mediating variables (intervention and control group) are shown in Table 1. Note: *P < .05 statistically signi cant differences in means between the groups.

Direct and indirect effects
We examined mediators of PLH intervention on reduction of substance use among parents\caregivers and their children, through three potential mediators: parenting stress, parental depression, and family poverty, at follow-up test (5-9 months following the intervention). Table 2 shows total, direct and indirect effect of each mediator on the outcome of the study. At the rst step of the analyses, each mediator was tested individually. At the second step, all mediators were tested in a Structural Equation Model (SEM) simultaneously.  The results of the SEM have shown that PLH intervention has a signi cant effect on reducing parental substance use (ß = − .167, P = .000) and adolescent substance use (ß = − .090, P = .043) at follow-up test (5-9 months). In addition, ndings showed that PLH intervention has a signi cant effect on reducing parental depression (ß = − .255, P = .000), parenting stress (ß = − .151, P = .002) and family poverty (ß = − .288, P = .000), at follow-up test.
Mediation analyses was examined using Bootstrap in AMOS. The results presented in Fig. 1 indicate that the PLH intervention effect on parental substance use reduction among parents\caregivers ran through one indirect pathway: reduction in parental depression. At follow-up test (5-9 months) PLH intervention had contributed to reduction in parental depression (ß = − .255, P < .001). There was no pathway from PLH intervention to parental substance use through parenting stress or family poverty. In other words, parenting stress and family poverty do not serve as mediators in the association between PLH intervention and reduced parental substance use. Furthermore, there were no pathways from PLH intervention to adolescent substance use through parenting stress, parental depression or family poverty. However, ndings showed a signi cant positive correlation between parental substance use and adolescent substance use (ß = .174, P = .006). The higher the levels of substance use among parents, the higher the levels of substance use among their children.

Discussion
The current study investigated the role of parental depression, parenting stress and family poverty as potential mediators of a parenting programme (PLH) on reduction of substance use among parents\caregivers and their children in South Africa. The ndings of the study help us to understand the mechanism behind the reduction of substance use among parents by showing that reduction in parental depression serves as a mediator between PLH intervention effect and parental substance use. In other words, improving parental mental health -reducing depression -leads to reduction in substance use among parents\caregivers. We can understand this mediation process in light of The General Strain Theory of Agnew [34]. According to this theory, substance use among adults is a coping mechanism to relieve negative feelings, such as stress, frustration and depression. With limited support and skills, parents may resort to substance use to escape their pain, negative feelings and cope with the problems they face. These ndings suggest that PLH intervention provides parents with skills and support that help them to cope in effective ways and avoid ineffective coping mechanisms, such as problematic alcohol use and drug use. In addition, the PLH intervention serves as a supportive environment for vulnerable parents, which contributes positively to their mental health by providing emotional and instrumental support as part of the intervention (such as stress reduction activities). Consistent with the results of previous studies [19,20], the ndings of the study indicated that parental substance use is positively and signi cantly correlated with substance use among their children. Based on Social Learning Theory [28], children who are exposed to parental substance use are more likely to be involved in substance use themselves. In light of these ndings, we identify a critical role of evidence-based parenting interventions in reducing risk behaviors among adolescents (such as substance use), by improving parental mental health and reducing risk behaviors among parents. However, the ndings of the study showed that parenting stress, parental depression and family poverty did not serve as mediators of PLH intervention on reduction in substance use among adolescents. It is recommended that future studies investigate potential pathways for the reduction in substance use among adolescents.
To the best of our knowledge, the current study is among the rst to investigate mediation pathways for reduction in substance use among parents and their children in LMIC. Findings indicate that parenting intervention has a signi cant effect on high risk behaviors (substance use) among parents and their children and parental mental health, despite working with vulnerable families. Strengths of the study include the pragmatic randomized trial method which provides high external validity. Furthermore, standardized measurement and intention-to-treat were used.
However, limitations also need to be acknowledged. First, mediation analyses were conducted at one time point only (5-9 months follow-up). A longer-term follow-up with multiple post-intervention assessments would have enabled us to examine potential effects and potential reverse causality between parental depression and reduction of parental substance use. Hence, future studies should conduct mediation analyses at more than one point in time, which would enable the hypothesized mediator to be measured before the outcome. Second, based on the ndings of the study, causal inferences of intervention components cannot be made. The ndings of the study have shown that improvement in parental mental health (less depression) mediates parental substance use. However, we cannot recognize which intervention components are responsible for this mediation effect. Therefore, it is recommended that future studies use other methods of identifying essential components, such as relaxation and coping skills with negative feelings, which might provide further insight into active core ingredients for parenting programs. This includes evidence from randomized micro-trials on the e cacy of discrete parenting techniques [35], and factorial experiment trials that test different components in relation to each other [36].
Lastly, this study makes an important contribution to the literature regarding the effectiveness of parenting programs at improving parental behavior (reducing substance use) through improving parental mental health (reducing parental depression) among families at high risk settings. Previous studies have shown that parenting interventions were effective in improving maternal mental health in high-income countries, such as reducing maternal stress, anxiety and depression among mothers of children with special needs [37]. However, little is known about the effectiveness of parenting programs in LMIC. The current study contributes by lling the gap regarding the pathways to effects of parenting intervention in reducing high risk behaviors among parents for adolescents in vulnerable communities. Nevertheless, we recommend that future researches examine the mechanism of reducing substance use among parents\caregivers in other settings in LMIC.

Conclusion
The ndings of the current study emphasize the importance of understanding the challenges that vulnerable families face which negatively affect their mental health and increase the likelihood of involvement in high-risk behaviors, such as substance use. These ndings highlight the fact that we need to create supportive environments and systems for parents who suffer from emotional strain and mental health problems. Professionals need to adopt an empathic approach toward vulnerable families which would contribute towards better understanding for their needs and challenges. An empathic approach would contribute to building effective psycho-social interventions and prevention programs that target families at risk.

Competing interests
LC and JML are co-developers of the PLH for Adolescents programs, which are licensed under a Creative Commons 4.0 Non-commercial No Derivatives license. JML is also the Executive Director of Clowns without Borders South Africa, a non-pro t institution responsible for the dissemination of the program. JML also receives occasional fees for providing training and supervision to facilitators and coaches. JML and LC have participated (and are participating) in a number of research studies involving the programme, as investigators, and the Universities of Oxford, Glasgow and Cape Town receive research funding for these. Con ict is avoided by declaring this potential con ict of interests; and by conducting and disseminating rigorous, transparent and impartial evaluation research on both this and other similar parenting programs. AM, FM, JD, YS and OG have no competing interests or other interests that might be perceived to in uence the results of the study.
No pro t or nancial gain will be made from this programme.