A Multilevel Meta-analysis of Single-Case Research on Interventions for Internalizing Disorders in Children and Adolescents

Abstract

The effectiveness of interventions for internalizing disorders in children and adolescents was studied using a review and meta-analysis of published single-case research. Databases and other resources were searched for quantitative single-case studies in youth with anxiety, depressive, and posttraumatic stress disorders. Raw data from individual cases were aggregated and analyzed by means of multilevel meta-analytic models. Outcome variables were symptom severity assessed across baseline and treatment phases of the studies, and diagnostic status at post- and follow-up treatment. Single-case studies were rated for quality. We identified 71 studies including 321 cases (Mage = 10.66 years; 55% female). The mean quality of the studies was rated as below average, although there were considerable differences between the studies. Overall, positive within-person changes during the treatment phase in comparison to the baseline phase were found. In addition, positive changes in the diagnostic status were observed at post- and follow-up treatment. Yet high variability in treatment effects was found between cases and studies. This meta-analysis harvests the knowledge from published single-case research in youth-internalizing disorders and illustrates how within-person information from single-case studies can be summarized to explore the generalizability of the results from this type of research. The results emphasize the importance of keeping account of individual variability in providing and investigating youth interventions.

The effectiveness of Forensic Outpatient Systemic Therapy in the treatment of juvenile antisocial behavior: A study protocol of a Multiple Case Experimental Design

“…First, the MCED design has several strengths (see Introduction ). Most importantly, the design allows to study the within-person intervention effects [ 44 ] and possible individual variability in processes of change [ 45 ] during the course of FAST. Second, the study uses an idiosyncratic measure of client formulated subgoals.…”

“…First, MCEDs can capture within-person changes and intervention effects [ 40 ] that might not be detected using group-level analyses [ 42 , 43 ]. Individual variability in response to treatment seems overlooked in group-level studies on youth interventions [ 44 ], highlighting the importance of combining group-level studies with MCEDs. Second, MCEDs allow a precise study of processes of change [ 45 ].…”

“…Third, the multiple measurements within each phase of the MCED design allow for a relatively small sample size [ 45 ]. Fourth, the design allows to assess if the intervention effect and mediating mechanisms vary between participants, and therefore to what extent effects and mechanisms can be generalized to other cases [ 44 ]. Previous MCED intervention studies have found individual differences in the processes of change [ 49 – 51 ], substantiating the importance of utilizing this design in intervention research.…”

The Effectiveness of Forensic Outpatient Systemic Therapy in the Treatment of Juvenile Antisocial Behavior: A Study Protocol of a Multiple Case Experimental Design

“…Third, the multiple measurements within each phase of the MCED design allow for a relatively small sample size [45]. Fourth, the design allows to assess if the intervention effect and mediating mechanisms vary between participants, and therefore to what extent effects and mechanisms can be generalized to other cases [44]. Previous MCED intervention studies have found individual differences in the processes of change [49][50][51], substantiating the importance of utilizing this design in intervention research.…”

How did the Treatment Work for Robin? And for Dylan? Studying Individual Youth Treatment Mediators Using Single-Case Experimental Designs

“…On the other hand, however, averaging participants’ scores and effects sizes (as in meta-analyses) is problematic and leads to loss of valuable information about individual variations in treatment effects. As mentioned, youth mental health problems are heterogeneous in nature and treatment effects that evolve within-persons cannot be captured by between-persons comparisons (Maric et al, 2023 ; Schuurman, 2023 ).…”