Sudden Gains and Early Response in Outpatient Psychotherapy: Predicting Symptom Change

Abstract

Background: Although sudden gains and early response are established as reliable predictors of psychotherapy outcomes, consistent findings regarding the factors predicting these patterns of therapeutic change are still lacking. So far, demographic and clinical variables have provided only a limited understanding of why some patients experience sudden gains and early response, while others do not, or even experience sudden losses.

Methods: This prospective, trans-diagnostic study aims to identify therapeutic process variables and patient variables related to therapy that predict sudden gains, sudden losses, and early response in routine outpatient psychotherapy. Special attention is given to common factors as mechanisms of change that operate across different therapeutic approaches, including therapeutic alliance, resource activation, problem activation, problem solving, and motivational clarification.

Treatment trajectories of 300 patients in a psychotherapy training center will be evaluated from initial sessions to session 27, using weekly therapy monitoring, including brief measures of symptomatic distress, daily functioning, and common factors. Follow-up data will be collected up to three months after treatment termination. Early response is defined as reliable symptom improvement by session 5, and sudden gains and losses are determined according to established criteria. Regression analyses will be used to examine the contribution of therapeutic process variables, their temporal dynamics, and patient variables related to therapy to predicting sudden gains, sudden losses, and early response. In addition, the study will investigate whether reduction in symptomatic distress is accompanied by improvements in daily functioning.

If the monitoring system detects sudden gains, qualitative telephone interviews will be conducted to explore patients’ subjective attributions of change mechanisms.

Discussion: An enhanced understanding of change mechanisms may help refine psychotherapy processes and support more targeted treatment planning. Methodological and practical challenges of the study are discussed. Clinical trial registration: https://www.drks.de/search/de/trial/DRKS00039264, identifier DRKS00039264.

1.1 Background and Rationale

Over the past decade, the importance of early treatment response has been examined in numerous studies, predominantly pharmacological, especially in cases of depression and obsessive-compulsive disorder. Meta-analytic results indicate that a symptom improvement of 20 to 50 percent in the first four weeks predicts response to later treatment in treatment-resistant depression, while the absence of such early improvement significantly reduces the probability of later remission (Olgiati et al., 2018; Wagner et al., 2017).

1 Introduction

In this context, the value of routine treatment monitoring is emphasized within pharmacotherapy (Wagner et al., 2017).

Studies on early response in psychotherapy or combined therapy have received increasing attention in recent years, with research examining their significance for treatment outcomes (Rubel et al., 2015). Solid and replicated evidence shows that an early response to therapy is a reliable prognostic indicator of treatment success for depression (Schindler et al., 2013; Schlagert and Hiller, 2017; Persons and Thomas, 2019; Vittengl et al., 2019) and anxiety (Beard and Delgadillo, 2019; Bradford et al., 2011; Lutz et al., 2014; Vîslă et al., 2023). Particularly in the field of eating disorders, several studies — some with large effect sizes — demonstrate the importance of early treatment response for a positive therapeutic outcome (Chang et al., 2021; Chen et al., 2017; Greenberg et al., 2022; Wales et al., 2016).

In contrast, the absence of an early response has been associated with a smaller reduction in symptoms, symptom deterioration, and lower remission rates at the end of treatment (Schlagert and Hiller, 2015, 2017; Vittengl et al., 2019).

The pattern of early response has been documented across a wide range of psychotherapy outcomes (Hunter et al., 2010), across different therapeutic approaches (Crits-Christoph et al., 2001; Gunlicks-Stoessel and Mufson, 2011), and across diagnostic groups (Bradford et al., 2011; Hayes et al., 2007; Lewis et al., 2012). Overall, the greatest change in symptom severity during psychotherapy occurs in the early phase of treatment (Rubel et al., 2015).

Despite extensive research, relatively little is known about the factors that determine early response (Bohart and Wade, 2013).

Some studies have linked higher educational level, employment, and social support with an increased likelihood of early response, while the tendency to avoid feelings or unpleasant states, chronic mental illness, and psychiatric comorbidity have been associated with a decreased likelihood (Joska et al., 2023; Melchior et al., 2016). However, many studies have reported no associations with sociodemographic variables (e.g., age, sex) or clinical characteristics (e.g., symptom severity and functional level at treatment onset, psychiatric comorbidity) (Bradford et al., 2011; Kelley et al., 2018; Kleinstäuber et al., 2017; Schlagert and Hiller, 2017; Vaz et al., 2014).

Therapy- and therapist-related variables have been examined far less frequently, and the variables studied so far (e.g., treatment expectations, experience