Marija Maric

Ten ways to improve the use of statistical mediation analysis in the practice of child and adolescent treatment research

Despite guidelines and repeated calls from the literature, statistical mediation analysis in youth treatment outcome research is rare. Even more concerning is that many studies that have reported mediation analyses do not fulfill basic requirements for mediation analysis, providing inconclusive data and clinical implications. As a result, after more than five decades of research, it is still largely unknown through which processes youth treatment works and what the effective treatment components are. In this article, we present ten ways in which the use of statistical mediation analysis in youth treatment outcome research may be improved. These ten ways are related both to conceptual and methodological issues. In discussing how youth clinical researchers may optimally implement these directions, we argue that studies should employ the strongest research designs possible. In so doing, we describe different levels of a mediation evidence ladder. Studies on each step of the ladder contribute to an understanding of mediation processes, but the strongest evidence for mediation is provided by studies that can be classified at the highest level. With the help of the ladder of mediation evidence, results from youth mediation treatment outcome research can be evaluated on their scientific as well as clinical impact.

Cognitive Mediation of Cognitive-Behavioural Therapy Outcomes for Anxiety-Based School Refusal

BACKGROUND Cognitive-behavioural therapy (CBT) has proven to be effective for anxiety-based school refusal, but it is still unknown how CBT for school refusal works, or through which mechanisms. AIMS Innovative statistical approaches for analyzing small uncontrolled samples were used to investigate the role of self-efficacy in mediating CBT outcomes for anxiety-based school refusal. METHOD Participants were 19 adolescents (12 to 17 years) who completed a manual-based cognitive-behavioural treatment. Primary outcomes (school attendance; school-related fear; anxiety) and secondary outcomes (depression; internalizing problems) were assessed at post-treatment and 2-month follow-up. RESULTS Post-treatment increases in school attendance and decreases in fear about attending school the next day were found to be mediated by self-efficacy. Mediating effects were not observed at 2-month follow-up. CONCLUSIONS These findings provide partial support for the role of self-efficacy in mediating the outcome of CBT for school refusal. They contribute to a small body of literature suggesting that cognitive change enhances CBT outcomes for young people with internalizing problems. Regarding methodology, the product of coefficient test appears to be a valuable way to study mediation in outcome studies involving small samples.

Distorted Cognitive Processing in Youth: The Structure of Negative Cognitive Errors and Their Associations with Anxiety

The Children’s Negative Cognitive Error Questionnaire (CNCEQ) is commonly used to measure four errors in young people’s thinking, but research has failed to support the factorial validity of the measure. The primary objective of the present study was to examine the factor structure of a refined and extended version of the CNCEQ. Revision of the CNCEQ involved the exclusion of items rated as contaminated, and the addition of items measuring cognitive errors closely associated with anxiety (‘threat conclusion’ and ‘underestimation of the ability to cope’). A secondary objective was to determine the relation between the negative cognitive errors and anxiety. Principal component analysis of data from 481 children and adolescents indicated five distinct negative cognitive error subscales labeled ‘underestimation of the ability to cope’, ‘personalizing without mind reading’, ‘selective abstraction’, ‘overgeneralizing’, and ‘mind reading’ which contained the new ‘threat conclusion’ items. Confirmatory factor analysis in an independent sample of 295 children and adolescents yielded further support for the five-factor solution. All cognitive errors except ‘selective abstraction’ were correlated with anxiety. Multiple regression analysis indicated that the strongest predictors of anxiety were the two subscales containing new items, namely ‘underestimation of the ability to cope’ and ‘mind reading’. The results are discussed with respect to further development of the instrument so as to advance the assessment of distorted cognitive processing in young people with internalizing symptoms.

The role of cognition in school refusal: an investigation of automatic thoughts and cognitive errors.

AIMS The purpose of this study was to investigate the cognitions of anxious school refusers. The cognitive constructs under investigation included negative cognition commonly linked to youth anxiety (i.e. negative automatic thoughts and cognitive errors) and positive automatic thoughts. METHOD The cognition of school refusers (n = 50) and youth from a community sample (n = 181) was assessed with the Childrens Automatic Thoughts Scale-Negative/Positive and the Childrens Negative Cognitive Error Questionnaire-Revised. RESULTS When controlling for anxiety, school refusers were found to report more negative automatic thoughts concerning personal failure, fewer negative automatic thoughts concerning hostility, and fewer positive automatic thoughts. Negative automatic thoughts concerning personal failure and hostility, and the negative cognitive error of overgeneralizing were found to independently predict school refusal. CONCLUSIONS The findings underscore the importance of further researching the role of cognition in the development, maintenance, and treatment of anxiety-based school refusal.

Evaluating Statistical and Clinical Significance of Intervention Effects in Single-Case Experimental Designs: An SPSS Method to Analyze Univariate Data

Single-case experimental designs are useful methods in clinical research practice to investigate individual client progress. Their proliferation might have been hampered by methodological challenges such as the difficulty applying existing statistical procedures. In this article, we describe a data-analytic method to analyze univariate (i.e., one symptom) single-case data using the common package SPSS. This method can help the clinical researcher to investigate whether an intervention works as compared with a baseline period or another intervention type, and to determine whether symptom improvement is clinically significant. First, we describe the statistical method in a conceptual way and show how it can be implemented in SPSS. Simulation studies were performed to determine the number of observation points required per intervention phase. Second, to illustrate this method and its implications, we present a case study of an adolescent with anxiety disorders treated with cognitive-behavioral therapy techniques in an outpatient psychotherapy clinic, whose symptoms were regularly assessed before each session. We provide a description of the data analyses and results of this case study. Finally, we discuss the advantages and shortcomings of the proposed method.

Parental Involvement in CBT for Anxiety-Disordered Youth Revisited: Family CBT Outperforms Child CBT in the Long Term for Children With Comorbid ADHD Symptoms:

Objective: The objective of this study was to examine the efficacy of child cognitive-behavioral therapy (CCBT) versus family CBT (FCBT) in anxiety-disordered youth with high and low comorbid ADHD symptoms. Method: Youth with anxiety disorders (n = 123, aged 8-18) were classified in four groups according to (a) the type of CBT received (child vs. family) and (b) their comorbid ADHD symptoms, measured with the Child Behavior Checklist (CBCL) Attention Problems syndrome scale level (normal vs. [sub]clinical). Severity of anxiety disorders was assessed with Anxiety Disorders Interview Schedule–Child and Parent (ADIS-C/P) version and anxiety symptoms via a 71-item anxiety symptom questionnaire, the Screen for Child Anxiety and Related Emotional Disorders (SCARED-71), before and after CBT, and at 3 months and 1-year follow-ups. Results: Based on the severity of anxiety disorders, children with high ADHD symptoms profit more from FCBT than CCBT in the long term. For children low on ADHD symptoms, and for anxiety symptoms and attention problems, no differences between CCBT and FCBT occurred. Conclusion: Family involvement seems a valuable addition to CBT for children with comorbid anxiety and ADHD symptoms.

Functional Assessment of School Attendance Problems: An Adapted Version of the School Refusal Assessment Scale-Revised.

The School Refusal Assessment Scale (SRAS) was developed to identify four factors that might maintain a youth’s school attendance problem (SAP), and thus be targeted for treatment. There is still limited support for the four-factor model inherent to the SRAS and its revision (SRAS-R). Recent studies indicate problems with the wording of eight items added to the SRAS to form the SRAS-R. We examined the factorial validity of an adapted item set comprising 16 of the 24 SRAS-R items and eight items developed for this study. The eight items paralleled the content of the SRAS-R items being replaced but were less complex and ambiguous. Data were gathered from 199 youth with a SAP and 131 parents. Confirmatory factor analysis (CFA) of the adapted item set supported a four-factor model. Internal consistency reliability of the subscales was higher than it is commonly reported in SRAS-R studies. Concurrent validity was supported by associations between the four factors and measures of internalizing or externalizing behavior. The adapted SRAS-R may help professionals reliably assess the relative strength of factors maintaining SAPs. This is one of the few studies conducted independent of the instrument’s developer and in a school culture different from that where the instrument is usually tested.

Differences in changes in health-related anxiety between Western and non-Western participants in a trauma-focused study†

Disaster victims from ethnic minorities manifest more health complaints and concerns than others following a medical investigation. The authors aimed at analyzing ethnicity as a proxy for risk factors predictive of changes in health-related anxiety, and mediators that explain ethnic group differences after participating in a medical investigation. Western (n = 406) and non-Western participants (n = 379) were assessed at baseline and 12-week follow-up. Education, unemployment, years of residence, and posttraumatic stress disorder symptoms were independent predictors of changes in health-related anxiety, excluding ethnicity. The predictive value of ethnicity was mediated mainly by changes in psychopathology, fatigue, and quality of life. Stronger responses to a trauma-related investigation by more vulnerable ethnic minority groups may explain their enhanced health-related anxiety.

Executive function as a mediator in the link between single or complex trauma and posttraumatic stress in children and adolescents

PurposeIn this study, we examined whether there is a mediating role of executive function (EF) in the relationship between trauma exposure and posttraumatic stress in youth.MethodsChildren and adolescents exposed to trauma were recruited at an academic center for child psychiatry in The Netherlands. The total sample consisted of 119 children from 9 to 17 years old (M = 13.65, SD = 2.45). Based on retrospective life event information, the sample was divided into three groups: a single trauma group (n = 41), a complex trauma group (n = 38), and a control group that was not exposed to traumatic events (n = 40).ResultsOur findings revealed that youth exposed to complex trauma had more deficits in EF compared to youth in the single trauma and control groups. EF was found to partly mediate posttraumatic stress symptoms for youth exposed to complex trauma, but not for youth exposed to single trauma. Youth exposed to complex trauma showed more deficits in EF, which was in turn associated with higher levels of posttraumatic stress symptoms.ConclusionsOur findings provide partial support for the role of EF in mediating posttraumatic stress outcomes for youth exposed to complex trauma. This points to the important role of EF in the etiology and treatment of complexly traumatized youth.