Modeling and treating internalizing psychopathology in a clinical trial: a latent variable structural equation...

Area of Science:

• Psychiatry and Clinical Psychology
• Psychopathology Research
• Treatment Outcome Analysis

Background:

• Clinical trials often focus on single diagnoses, but internalizing disorders frequently co-occur.
• A method is needed to quantify changes across a spectrum of internalizing symptoms in trials.
• This study addresses the challenge of comorbidity in transdiagnostic intervention research.

Purpose of the Study:

• To develop a practical and parsimonious method for characterizing and quantifying changes in a broad spectrum of internalizing psychopathology.
• To assess treatment effects on a transdiagnostic range of internalizing symptoms in patients with alcohol dependence.
• To compare the efficacy of cognitive-behavioral therapy (CBT) against progressive muscle relaxation training (PMRT) for internalizing disorders.

Main Methods:

• Randomized controlled trial comparing six-session CBT to PMRT in alcohol dependence patients with internalizing disorders.
• Internalizing psychopathology was assessed at baseline and 4-month follow-up using symptom domain surveys.
• Exploratory structural equation modeling (ESEM) and confirmatory factor analysis (CFA) were used to analyze the latent structure of symptoms.

Main Results:

• ESEM identified a two-factor structure: Distress (depression, trait anxiety, worry) and Fear (panic anxiety, social anxiety, agoraphobia) at both time points.
• CFA confirmed measurement invariance of the symptom structure between baseline and follow-up.
• Both groups showed significant reductions in Fear and Distress, with CBT demonstrating a small, statistically significant advantage in Distress reduction.

Conclusions:

• The proposed method effectively models comorbidity in clinical trials for internalizing disorders.
• Findings support the dimensional structure of internalizing psychopathology.
• The study provides a practical approach for analyzing transdiagnostic treatment effects on a spectrum of internalizing symptoms.