Understanding how and why psychotherapy leads to change

Abstract

The rich research literature on psychotherapies for children, adolescents, and adults has identified several interventions that can ameliorate or effect significant change in psychiatric disorders and a variety of social, behavioral, and emotional problems and can enhance medical outcomes and recovery. After decades of psychotherapy research and thousands of studies, there is no evidence-based explanation of how or why even the most well-studied interventions produce change, that is, the mechanisms through which treatments operate. This article discusses central requirements for demonstrating mediators and mechanisms of change. Also presented are promising lines of work to identify mediators and mechanisms, ways of bringing to bear multiple types of evidence, recommendations to make progress in understanding how therapy works, and conceptual and research challenges in evaluating mediators and mechanisms.

ABSTRACT

Die reichhaltige Literatur über Psychotherapien für Kinder, Jugendliche und Erwachsene hat mehrere Interventionen ermittelt, welche psychische Störungen und eine Vielfalt an sozialen, behavioralen und emotionalen Problemen verbessern oder signifikante Verbesserungen bewirken können, sowie das medizinische Ergebnis und die Erholung fördern. Nach Jahrzehnten an Psychotherapieforschung und tausender Studien, gibt es keine evidenzbasierte Erklärung, wie oder warum selbst die bestuntersuchtesten Interventionen Veränderungen – welches der Mechanismus ist, durch welchen die Behandlung wirkt – bewirken. Dieser Artikel diskutiert zentrale Bedingungen um Mediatoren und den Veränderungsmechanismus aufzuzeigen. Weiter werden vorgestellt: vielversprechende Arbeitsfelder um Mediatoren und Mechanismen zu ermitteln, Wege um mehrere Arten von Evidenz anzuwenden, Vorschläge um besser zu verstehen, warum Therapie wirkt sowie konzeptuelle und Forschungsherausforderungen bei der Untersuchung von Mediatoren und Mechanismen.

RÉSUMÉ

Une riche littérature de recherche sur les psychothérapies pour enfants, adolescents et adultes a identifié plusieurs interventions qui peuvent améliorer ou effectuer des changements significatifs pour des troubles psychiatriques et une variété de problèmes sociaux, comportementaux et émotionnels et qui peuvent améliorer les résultats médicaux et la rémission. Après plusieurs décades de recherche en psychothérapie et des milliers d’études, il n'y a pas d'explication basée sur l’évidence sur comment et pourquoi les interventions les plus étudiées produisent un changement, c'est-à-dire les mécanismes par lesquels le traitement opère. Cet article discute les exigences de base pour démontrer les médiateurs et les mécanismes de changement. Sont également présentées les lignes de recherche les plus prometteuses pour identifier ces médiateurs et ces mécanismes, les manières de fournir de multiples types d’évidence empirique, les recommandations pour progresser dans la compréhension de comment la thérapie marche, et les défis conceptuels et de recherche pour évaluer ces médiateurs et ces mécanismes.

A vasta investigação em psicoterapias para crianças, adolescentes e adultos tem vindo a identificar várias intervenções que podem melhorar o induzir mudanças significativas em desordem psiquiátricas e numa variedade de problemas sociais, comportamentais e emocionais, assim como podem potenciar resultados médicos e a recuperação. Após décadas de investigação em psicoterapia e milhares de estudos, não há ainda uma explicação baseada na evidência de com e porque é que até mesmo as intervenções mais bem estudadas produzem mudança, isto é, quais os mecanismos através dos quais os tratamento operam. Este artigo discute requisitos centrais para demonstrar mediadores e mecanismos de mudança. Apresenta ainda linhas de trabalho promissoras para identificar mediadores e mecanismos, meios de trazer à luz múltiplos tipos de evidência, recomendações para que haja progresso na compreensão de como a terapia funciona, e desafios conceptuais e de investigação na avaliação de mediadores e mecanismos.

ABSTRACT

La ricca letteratura esistente in psicoterapia per bambini, per adolescenti e per adulti ha individuato diversi interventi che potrebbero portare a miglioramenti significativi circa i cambiamenti verificatisi su disturbi psichiatrici e su una varietà di problematiche sociali, comportamentali ed emotive. Dopo decenni di ricerca in psicoterapia e di migliaia di studi realizzati in merito a tale argomento, sono state avanzate delle spiegazioni basate sulla evidenza di dove e quando effettuare l'intervento per far avvenire il cambiamento. In questo articolo si dimostrerà qual è il mediatore e il meccanismo in base al quale avviene il cambiamento.

Keywords:

• mediators and mechanisms of psychotherapy

Notes

1. Statistical evaluation is intertwined with the conceptualization and evaluations of mediators (e.g., Baron & Kenny, 1986; Kenny, Kashy, & Bolger, 1998; Kraemer, Kiernan, Essex, & Kupfer, 2008; MacKinnon, 2008; Shrout & Bolger, 2002). The present article focuses on conceptual and methodological requirements. Not only have these received less attention, but applications of statistical methods occasionally have led to unwarranted conclusions in part because critical requirements (e.g., about the time line) have not been met. Also, statistical models can lead to quite different conclusions about mediation and hence deserve their own detailed assessment and presentation (Kraemer et al., 2008).

2. This strategy bears similarity to but can be distinguished from dismantling therapy studies in which various components (procedures) of treatment are separated and provided to different groups to identify necessary, sufficient, and facilitative components of a treatment package. The focus is on procedures and what is needed for therapeutic change. Although this might be considered to imply mechanisms, it is not a direct test of mechanisms. The knockout strategy here focuses on critical mechanisms and manipulation of the mechanism.