# Mental Health Impacts of AI Companions: Triangulating Social Media Quasi-Experiments, User Perspectives, and Relational Theory

arXiv: https://arxiv.org/abs/2509.22505 · HTML: https://mlsanity.com/paper/2509.22505/

## Key facts

- Cited by 9 papers in the map (data through 14 Oct 2026).
- Builds on 25 of its 142 references that are in the map.
- First posted on arXiv 26 Sep 2025.

## Builds on (most cited first, 25 of 25)

- [Distributed Representations of Words and Phrases and their Compositionality](https://mlsanity.com/paper/1310.4546/) (2013)
- [The Design and Implementation of XiaoIce, an Empathetic Social Chatbot](https://mlsanity.com/paper/1812.08989/) (2018)
- [Understanding the Benefits and Challenges of Using Large Language Model-based Conversational Agents for Mental Well-being Support](https://mlsanity.com/paper/2307.15810/) (2023)
- [The Dark Side of AI Companionship: A Taxonomy of Harmful Algorithmic Behaviors in Human-AI Relationships](https://mlsanity.com/paper/2410.20130/) (2024)
- [Facilitating Self-Guided Mental Health Interventions Through Human-Language Model Interaction: A Case Study of Cognitive Restructuring](https://mlsanity.com/paper/2310.15461/) (2023)
- [AI Companions Reduce Loneliness](https://mlsanity.com/paper/2407.19096/) (2024)
- [From Lived Experience to Insight: Unpacking the Psychological Risks of Using AI Conversational Agents](https://mlsanity.com/paper/2412.07951/) (2024)
- ["My Boyfriend is AI": A Computational Analysis of Human-AI Companionship in Reddit's AI Community](https://mlsanity.com/paper/2509.11391/) (2025)
- [Chatbots as social companions: How people perceive consciousness, human likeness, and social health benefits in machines](https://mlsanity.com/paper/2311.10599/) (2023)
- [Lessons From an App Update at Replika AI: Identity Discontinuity in Human-AI Relationships](https://mlsanity.com/paper/2412.14190/) (2024)
- [Are Deepfakes Concerning? Analyzing Conversations of Deepfakes on Reddit and Exploring Societal Implications](https://mlsanity.com/paper/2203.15044/) (2022)
- [AI Chatbots for Mental Health: Values and Harms from Lived Experiences of Depression](https://mlsanity.com/paper/2504.18932/) (2025)
- [Mental Health Coping Stories on Social Media: A Causal-Inference Study of Papageno Effect](https://mlsanity.com/paper/2302.09885/) (2023)
- [Chatbot Companionship: A Mixed-Methods Study of Companion Chatbot Usage Patterns and Their Relationship to Loneliness in Active Users](https://mlsanity.com/paper/2410.21596/) (2024)
- [Stranger Danger! Cross-Community Interactions with Fringe Users Increase the Growth of Fringe Communities on Reddit](https://mlsanity.com/paper/2310.12186/) (2023)
- [Does Positive Reinforcement Work?: A Quasi-Experimental Study of the Effects of Positive Feedback on Reddit](https://mlsanity.com/paper/2409.20410/) (2024)
- [Interpersonal Theory of Suicide as a Lens to Examine Suicidal Ideation in Online Spaces](https://mlsanity.com/paper/2504.13277/) (2025)
- [Many Ways to Be Lonely: Fine-Grained Characterization of Loneliness and Its Potential Changes in COVID-19](https://mlsanity.com/paper/2201.07423/) (2022)
- ["AI Afterlife" as Digital Legacy: Perceptions, Expectations, and Concerns](https://mlsanity.com/paper/2502.10924/) (2025)
- [The Benefits of Prosociality towards AI Agents: Examining the Effects of Helping AI Agents on Human Well-Being](https://mlsanity.com/paper/2502.02911/) (2025)
- [The Partner Modelling Questionnaire: A validated self-report measure of perceptions toward machines as dialogue partners](https://mlsanity.com/paper/2308.07164/) (2023)
- [Minority Stress Experienced by LGBTQ Online Communities during the COVID-19 Pandemic](https://mlsanity.com/paper/2205.09511/) (2022)
- [Capturing Dynamics in Online Public Discourse: A Case Study of Universal Basic Income Discussions on Reddit](https://mlsanity.com/paper/2312.09611/) (2023)
- [Hashtag Re-Appropriation for Audience Control on Recommendation-Driven Social Media Xiaohongshu (rednote)](https://mlsanity.com/paper/2501.18210/) (2025)
- [How Conversational Structure and Style Shape Online Community Experiences](https://mlsanity.com/paper/2508.08596/) (2025)

## Built on by (most cited first, 9 of 9)

- [AI Psychosis: Does Conversational AI Amplify Delusion-Related Language?](https://mlsanity.com/paper/2603.19574/) (2026)
- [The Hidden Toll of Social Media News: Causal Effects on Psychosocial Wellbeing](https://mlsanity.com/paper/2601.13487/) (2026)
- [Synergy: A Next-Generation General-Purpose Agent for Open Agentic Web](https://mlsanity.com/paper/2603.28428/) (2026)
- [Deco: Extending Cherished Physical Objects into AI Companion Agents through Dual Embodiment](https://mlsanity.com/paper/2605.03882/) (2026)
- [Algorithmic Cultivation: How Social Media Feeds Shape User Language](https://mlsanity.com/paper/2605.17010/) (2026)
- [When AI Says "I have been in similar situations": Synthetic Lived Experience in Peer-Like Caregiver Support](https://mlsanity.com/paper/2606.18057/) (2026)
- [Examining Human-Like Behaviors in LLMs: A Multi-Dimensional Analysis of Model Behaviors, User Factors, and System Prompts](https://mlsanity.com/paper/2606.18258/) (2026)
- [Disrupted Companionship: A Risk Assessment Framework and Cross-Platform Quantitative Analysis of Psychosocial Responses to AI Companion Disruptions](https://mlsanity.com/paper/2609.16907/) (2026)
- [CompanionSafe: From Multi-turn Safety Evaluation to Guardrails for AI Companions](https://mlsanity.com/paper/2610.18095/) (2026)

## Abstract (arXiv)

AI-powered companion chatbots (AICCs) such as Replika are increasingly popular, offering empathetic interactions, yet their psychosocial impacts remain unclear. We examined how engaging with AICCs shaped wellbeing and how users perceived these experiences. First, we conducted a large-scale quasi-experimental study of longitudinal Reddit data, applying stratified propensity score matching and Difference-in-Differences regression. Findings revealed mixed effects -- greater grief expression and interpersonal focus, alongside increases in language about loneliness, depression, and suicidal ideation. Second, we complemented these results with 18 semi-structured interviews, which we thematically analyzed and contextualized using Knapp's relationship development model. We identified trajectories of initiation, escalation, and bonding, wherein AICCs provided emotional validation and social rehearsal but also carried risks of over-reliance and withdrawal. Triangulating across methods, we offer design implications for AI companions that scaffold healthy boundaries, support mindful engagement, support disclosure without dependency, and surface relationship stages -- maximizing psychosocial benefits while mitigating risks.