In an era where digital platforms are reshaping healthcare delivery, we have also seen the rise of online platforms for mental health consumption. While the literature on consumer behaviour in an online context is rich, mental health consumption presents a unique context requiring attention to personal health-related dynamics alongside the larger aspect of online consumption. This motivates the current study to conduct a multi-method study for understanding the phenomenon of online mental health consumption. We combine a systematic review of 105 articles (2014–2024) with topic modelling of 168,040 user reviews from mental health applications. We theorise how the logic of choice and care are at work in online mental health consumption. Our findings reveal a complex and dynamic interplay of ‘choice’-related enablers and ‘care’-related inhibitors, shaping online mental health consumption behaviour. While online platforms offer ‘choice’ for consuming mental health services by overcoming traditional barriers related to stigma and accessibility, their uptake at the same time is challenged by the emerging care-related factors such as trust and privacy concerns. An analysis of user reviews further reveals that consumer experiences focus on the service delivery quality, personalised user interfaces and technical platform reliability, which collectively demonstrate how users navigate between autonomous choice making and professional care expectations. This apparent tension between the ‘logics’ in mental health consumption online also informs the larger online consumption behaviour literature about attending to the constantly evolving, often competing logic in online platforms.