ConsistentMI

Consistent Client Simulation for Motivational Interviewing-based Counseling

Venue: ACL 2025 (Main Conference)
Paper: ACL Anthology

Overview

ConsistentMI simulates clients in motivational interviewing (MI) sessions with consistent behavior based on the Transtheoretical Model (Stages of Change). The client's responses adapt based on their current stage and the therapist's MI techniques.

Key Features

• Stage of Change Model: Precontemplation → Contemplation → Preparation → Action → Maintenance
• Consistent Behavior: Actions match the current stage
• Stage Transitions: Natural progression based on therapist's approach
• MI-Specific Responses: Reacts appropriately to OARS techniques

How It Works

1. Load Profile: Reads the character JSON (personas, beliefs, acceptable plans, motivation topics) and initializes stage and receptivity.
2. Initialize Prompts: Builds a system prompt that anchors the client’s behavior/goal and injects personas + beliefs for consistency.
3. Track Topic Engagement: Matches the therapist’s latest utterance to a motivation topic, then uses the topic graph distance to update engagement and count repeated off-topic turns.
4. Verify Motivation (Optional): If the therapist addresses the client’s core motivation, the client enters a short Motivation state for an acknowledging response.
5. Sample a Stage-Consistent Action: An LLM predicts an action distribution conditioned on recent context and the current stage.
6. Select Grounding Detail: For actions like Inform/Downplay/Blame/Hesitate/Plan, the client selects a relevant persona/belief/plan (only when the therapist asks a question) to ground the next reply.
7. Generate Reply: Renders a structured instruction (state + action + engagement + selected info) and calls the chat model to produce the final client utterance.

Action space in the current implementation:

• Precontemplation: Deny, Downplay, Blame, Inform, Engage (or Terminate after repeated off-topic turns)
• Contemplation: Inform, Engage, Hesitate, Doubt, Acknowledge
• Preparation: Inform, Engage, Reject, Accept, Plan
• Motivation: Acknowledge (then proceeds into Contemplation)

Usage

CLI

uv run python -m examples.simulate client=consistentMI therapist=CBT

Python

from omegaconf import OmegaConf
from patienthub.clients import get_client

config = OmegaConf.create({
    'agent_type': 'consistentMI',
    'model_type': 'OPENAI',
    'model_name': 'gpt-4o',
    'temperature': 0.7,
    'max_tokens': 1024,
    'max_retries': 3,
    'data_path': 'data/characters/ConsistentMI.json',
    'topics_path': 'data/resources/ConsistentMI/topics.json',
    'topic_graph_path': 'data/resources/ConsistentMI/topic_graph.json',
    'model_retriever': None,
    'data_idx': 0,
})

client = get_client(configs=config, lang='en')
client.set_therapist({'name': 'Counselor'})

# Client starts in precontemplation
response = client.generate_response(
    "I noticed you mentioned you've been drinking more lately. How do you feel about that?"
)
print(response)

Configuration

Option	Description	Default
data_path	Path to character file	data/characters/ConsistentMI.json
data_idx	Character index	0
topics_path	Topics from Wiki	data/resources/ConsistentMI/topics.json
topic_graph_path	Correlation between topics	data/resources/ConsistentMI/topic_graph.json
model_retriever	retrieve the most relevant topic	None

Character Data Format

{
    "idx": 25,
    "topic": "reducing drug use",
    "initial_stage": "Precontemplation",
    "suggestibilities": [
        3,
        3,
        3,
        2,
        3
    ],
    "Personas": [
        "You smoke weed to relax after a long day.",
        "Your wife is concerned about your smoking habits",
        "Your wife has pushed you to seek help.",
        "You have failed a UA at work.",
        "Your boss may fire you for failing the UA."
    ],
    "Acceptable Plans": [
        "You consider talking to his boss and taking steps to address his substance use to prevent losing his job."
    ],
    "Beliefs": [
        "You believe weed helps you unwind.",
        "You don't perceive smoking weed as a problem.",
        "You view smoking weed as a way to manage stress from working, paying the bills and house."
    ],
    "quality": "high",
    "Motivation": [
        "Career Break",
        "Employment",
        "Economy",
        "You are motivated because of the risk of smoking weed in career break for yourself, as you may lose your job."
    ],
    "Behavior": "drug use"
}

Stages of Change

Stage	Description	Typical Behaviors
Precontemplation	Not considering change	Denial, resistance, minimization
Contemplation	Aware but ambivalent	Weighing pros/cons, uncertainty
Preparation	Planning to change	Seeking information, small steps
Action	Actively changing	Implementing changes, seeking support
Maintenance	Sustaining change	Preventing relapse, building habits

Example Conversation

Therapist: "Thanks for coming in today. What brings you here?"

Client (Precontemplation): "My boss made me come. Apparently someone complained about smelling alcohol on my breath at work. I think they're overreacting—I just had a couple drinks at lunch."

Therapist: "It sounds frustrating to feel like others are making a big deal out of something. What's your take on your drinking?"

Client: "I mean, I drink, sure. But I'm not an alcoholic or anything. I can stop whenever I want. I just don't want to right now. Work's been stressful."

Therapist (using reflection): "Work stress has been a factor, and you feel in control of your drinking."

Client (slight shift): "Well... I guess sometimes I drink more than I plan to. But who doesn't, right?"

Best Practices

1. Use MI Therapist: Pair with therapist=MI for best results
2. Watch for Change Talk: Client will express change talk when therapist uses good MI
3. Avoid Confrontation: Confrontational approaches trigger resistance
4. Track Stage: Note when client shows signs of stage transition

Limitations

• Stage transitions may not perfectly match clinical expectations