Digital mental health resources have expanded rapidly in the wake of the COVID-19 pandemic, offering new opportunities to improve access to mental healthcare through technologies such as AI chatbots, mobile apps, and online platforms. Despite this growth, significant challenges persist, including low user retention, limited digital literacy, unclear privacy regulations, and insufficient evidence of clinical effectiveness and safety. AI chatbots, which act as virtual therapists or companions, provide counseling and personalized support, but raise concerns about user dependence, emotional outcomes, privacy, ethical risks, and bias. User experiences are mixed: while some report enhanced social health and reduced loneliness, others question the safety, crisis response, and overall reliability of these tools, particularly in unregulated settings. Vulnerable and underserved populations may face heightened risks, highlighting the need for engagement with individuals with lived experience to define safe and supportive interactions. This review critically examines the empirical and grey literature on AI chatbot use in mental healthcare, evaluating their benefits and limitations in terms of access, user engagement, risk management, and clinical integration. Key findings indicate that AI chatbots can complement traditional care and bridge service gaps. However, current evidence is constrained by short-term studies and a lack of diverse, long-term outcome data. The review underscores the importance of transparent operations, ethical governance, and hybrid care models combining technological and human oversight. Recommendations include stakeholder-driven deployment approaches, rigorous evaluation standards, and ongoing real-world validation to ensure equitable, safe, and effective use of AI chatbots in mental healthcare.
Context
The mental health treatment gap has worsened since the COVID-19 pandemic, which triggered a digital transformation of mental healthcare due to changing social dynamics, the widespread use of smartphones, and the proliferation of digital mental health tools
[1][2][3][4][5]. This technological shift has fundamentally altered how support is delivered by broadening accessibility and expanding reach for those seeking personalized mental health support.
Proliferation
Digital mental health tools—particularly those underpinned by Artificial Intelligence (AI) chatbots—are attractive because of their low cost, accessibility, and anonymity. However, the growing interest in AI chatbots has not yet translated into clinical benefits and improved outcomes for users (patients) with anxiety and depression
[6]. Questions remain with regard to the safe, engaging and effective integration into existing models of care
[7][8][9][10][11].
Despite there being more than 10,000 digital mental health resources globally, low user retention rates appear persistent in combination with a lack of digital literacy, clear privacy guidelines and proven clinical efficacy/integration, as well as human support in the app
[5][6]. AI chatbots operate in a largely unregulated environment, which exposes vulnerabilities, especially in underserved populations.
Mediators
Consequently, there are renewed calls for trained digital navigators to assist in the safe integration of technology into mental healthcare settings, driving engagement and supporting both the needs of the clinician and the patient
[5][12]. Digital navigators are professionals who support the integration and effective use of technology in mental healthcare by improving digital literacy and ensuring that these tools are integrated into clinical practice. A recent trial found that changes in the level of support provided by digital navigators directly affect how effective schizophrenia apps are, meaning that standardized training is essential to reliably evaluate these tools
[13].
Advanced Platforms
Generative AI (GenAI)-powered platforms, especially those using advanced Large Language Models (LLMs), are increasingly sought out for consulting about mental healthcare. However, these platforms often lack ongoing engagement and fall short of emotional intelligence and trauma-informed objectives in practice
[14][15][16][17][18]. LLMs like GPT-4 have shown that they can generate coherent text, maintain conversational context, and perform advisory or counseling tasks, making them suitable for various mental health applications
[19].
Increasingly, AI is being deployed as “agents” and “assistants” through “therapist” and “companion” types via mobile apps, web platforms and social robots
[20][21]. AI chatbots for mental healthcare generally come in rule-based, machine learning, and/or LLM systems. Functioning as autonomous agents, they assist with screening, prevention, monitoring, clinical assessment, treatment, emotional support and companionship.
Challenges
There is a lack of clinical evidence supporting AI-based therapy due to the limited conclusions regarding their efficacy and safety in clinical practice. For example, a narrative review of recent clinical studies on AI chatbots for anxiety and depression found them to be feasible and acceptable, but there is insufficient evidence of AI effectiveness, small and narrow samples, weak controls, and unexamined risks such as emotional dependence and parasocial relationships
[6]. The first randomized controlled trial (RCT) of a GenAI therapy chatbot (Therabot) demonstrated moderate symptom improvement for major depressive disorder, generalized anxiety disorder, and eating disorders
[22].
Public reactions to these technologies are mixed: while some appreciate the accessibility and affordability of AI mental health tools, others remain skeptical about their effectiveness, ethics, and safety
[23]. This uncertainty echoes broader frustrations with current mental health systems as well as cautious optimism about the potential of AI chatbots as complementary resources. There are complex issues that require exploration, notably algorithmic bias and errors, privacy risks, and the challenge of integrating AI chatbots into existing care structures. Notably, there is user perception and an ongoing ethical discussion where AI chatbots appear to exhibit consciousness—a phenomenon referred to as “Seemingly Conscious AI”
[24]. This is particularly important to understand for sensitive settings like elder care, where user safety and meaningful, evidence-based support are critical
[25][26].
While reviews and meta-analyses highlight the potential of technological innovation in mental health chatbots to improve outcomes across diverse settings, these tools are still largely untested in rigorous clinical efficacy trials
[27][28][29][30][31][32][33]. The integration of AI chatbots into clinical practice remains inadequately studied, with limited evidence supporting their effectiveness, safety, and capacity to deliver nuanced, meaningful support. Most research to date relies on small samples and lacks rigorous evaluation of real-world risks. As a result, it is still unclear whether AI chatbots can reliably meet the complex needs of mental healthcare, especially in sensitive or high-risk scenarios.
The global prevalence of AI chatbot use for mental health support remains uncertain; however, data from Australian samples showed that 28% of community members and 43% of mental health professionals reported using AI for mental health purposes
[34]. A 2025 survey of U.S. residents with ongoing mental health conditions found that nearly half used LLMs for psychological support in the past year—primarily for anxiety, personal advice, and depression—with most reporting improved mental health and high satisfaction
[35]. Some users rated LLMs more beneficial than traditional therapy, though a minority experienced harmful responses.
Following input from 171 mental health experts, OpenAI shared findings that a significant number of ChatGPT-5 users displayed signs of psychosis, mania, or suicidal planning and intent
[36]. The data also showed substantial improvements in the chatbot’s responses during crisis situations, with the most serious cases—such as suicide, psychosis, and over-reliance—being managed appropriately, and reliable support generally maintained in extended conversations. However, these results also highlight that there are still notable shortcomings in the performance of AI chatbots, underscoring the ongoing need to address challenges related to user engagement, safety, and effectiveness when integrating AI chatbots into healthcare and support systems.
Aim and Objectives
The aim of this review is to critically synthesize the current empirical and grey literature on AI chatbots in mental healthcare, evaluating their effectiveness, safety, and user engagement while identifying key challenges around clinical integration, ethical considerations, regulation, and the roles of digital navigators. By examining both the benefits and limitations of these technologies—including issues of access, digital literacy, and the management of potential risks—this review provides a foundation for understanding how AI chatbots can be responsibly developed and implemented to support diverse and vulnerable populations. In doing so, it clarifies the present landscape and outstanding questions, setting the stage for a focused discussion of the core problem underlying the use of AI chatbots in mental health.