PsyCLIENT: Client Simulation via Conversational Trajectory Modeling for Trainee Practice and Model Evaluation in Mental Health Counseling

TL;DR

PsyCLIENT introduces a conversational trajectory modeling framework for realistic, diverse client simulation in mental health counseling, especially addressing Chinese-language needs, enhancing training and evaluation of counseling systems.

Contribution

It presents a novel simulation framework conditioned on real-world trajectories and behavior labels, along with the first open-source Chinese client profile dataset, improving realism and diversity.

Findings

Outperforms baselines in authenticity and training effectiveness

Achieves about 95% expert confusion rate in discrimination tasks

Bridges the gap between theoretical profiles and realistic simulations

Abstract

LLM-based client simulation has emerged as a promising tool for training novice counselors and evaluating automated counseling systems. However, existing client simulation approaches face three key challenges: (1) limited diversity and realism in client profiles, (2) the lack of a principled framework for modeling realistic client behaviors, and (3) a scarcity in Chinese-language settings. To address these limitations, we propose PsyCLIENT, a novel simulation framework grounded in conversational trajectory modeling. By conditioning LLM generation on predefined real-world trajectories that incorporate explicit behavior labels and content constraints, our approach ensures diverse and realistic interactions. We further introduce PsyCLIENT-CP, the first open-source Chinese client profile dataset, covering 60 distinct counseling topics. Comprehensive evaluations involving licensed professional counselors demonstrate that PsyCLIENT significantly outperforms baselines in terms of authenticity and training effectiveness. Notably, the simulated clients are nearly indistinguishable from human clients, achieving an about 95\% expert confusion rate in discrimination tasks. These findings indicate that conversational trajectory modeling effectively bridges the gap between theoretical client profiles and dynamic, realistic simulations, offering a robust solution for mental health education and research. Code and data will be released to facilitate future research in mental health counseling.