Systematic Review and Meta-Analyses of Psychotherapies for Adolescents With Subclinical and Borderline Personality Disorder: Methodological Issues

Abstract

Dear Lakshmi N. Yatham, We thank Jennifer Wong, Anees Bahji, and Sarosh Khalid-Khan for a much needed systematic review of psychotherapies for adolescents with subclinical and borderline personality disorder (BPD). Previous reviews have largely excluded subclinical BPD presentations and therefore excluded the majority of the trials for this age-group. The authors found that psychotherapies for adolescents with subclinical and BPD are effective but that the efficacy was not statistically significant at follow-up. There are, however, some limitations to this review. First, we have not been able to retrieve any published protocol, which makes it difficult to determine whether the review could be prone to selective reporting bias. Second, the authors conclude that “the studies were rated as being of very high quality” (p. 5), but it is unclear on what ground this quality assessment was made. The use of tools like the Grading of Recommendations Assessment, Development and Evaluation could have increased the confidence of quality ratings. The authors conclude that the risk of bias was low on all domains except two instances with unclear risk of bias. However, the ratings on several domains may be too optimistic. For instance, it is left unaddressed that the developer of the experimental intervention was involved in four of the studies, which raises high risk of allegiance bias. Furthermore, all studies either did not publish a protocol or there were discrepancies between the protocols and the outcomes reported in the paper, thus warranting an unclear or high risk of selective outcome reporting bias. Concern about how missing data was handled, i.e. incomplete outcome data bias, in instances where no intention-to-treat analysis or multiple imputation were applied, only completers were included or there were extensive loss to follow-up are also not addressed. Instances of missing or unclear adherence ratings or skewed intensity between the experimental and control interventions are also not addressed even though these pose concerns for adherence or attention bias. Additionally, the review is prone to some methodological issues concerning clinical heterogeneity. The authors pooled experimental therapies and control therapies into metaanalyses not taking into consideration the heterogeneity of the experimental interventions, control treatments, type of outcome assessors, and time points. Lastly, the authors only searched seven electronic databases for relevant articles and used an English language restriction. This may have caused for some randomized controlled trials to be left out, for example, Santisteban et al., Salzer et al., and a pilot study by Gleeson et al. Valuable information have thus not been included. Publishing a systematic review with risk of bias assessments of psychological therapies for adolescents with BPD or subclinical BPD is an important first step to outline the evidence base. Early intervention and stage-linked care in potentially serious mental disorders like BPD is an important goal, when we focus on the period of peak risk of (including unclinical) onset between puberty and mature adulthood. However, the aforementioned limitations could lead to valuable information being missed and also drawing too optimistic conclusions about the quality of the findings. Future reviews should address these limitations more thoroughly. Sincerely,