First impressions matter: The influence of initial assessments on psychological treatment initiation and subsequent dropout.

Objective: This study investigated if patients' experience of an initial assessment may be associated with outcome expectations, and with subsequent treatment attendance.

Method: The sample comprised n = 6051 patients with depression/anxiety disorders, nested within k = 148 assessing therapists. Multilevel modelling (MLM) was used to examine therapist effects on treatment initiation and subsequent dropout, adjusting for patient-level characteristics. We tested associations between early outcome expectancy measured at an initial assessment with attendance at a first therapy session, and with dropout after initiation. Variability in mean expectancy ratings in the caseloads of assessing therapists was examined using the intracluster correlation coefficient (ICC).

Results: Therapist effects partly explained the variance in treatment initiation and dropout. Pre-treatment outcome expectations significantly predicted treatment initiation but not dropout for the subgroup of patients who started treatment. Approximately 16% of variability in mean expectancy ratings was explained by therapist effects (ICC = 0.159) after controlling for patient-level covariates.

Conclusions: Patients assessed by some therapists are more likely to have higher outcome expectations, which influences their decision to initiate treatment thereafter. Once patients start therapy, early expectancy measured at assessment no longer influences their attendance, but the "first impression" from an initial assessment does influence their subsequent likelihood of dropout.