Access to accurate and accessible health information, support, and services are required for effective health care decision-making. This applies across the health care continuum and is inclusive of self-health promotion and participation in shared decision-making with health care provider teams [1-6]. Individuals rely on family, friends, and health care professionals for support, yet seek health-related information online at the same time [7,8]. In general, adolescents live in a hybrid reality—a mix of offline and online worlds [9]. They are increasingly seeking information about healthy lifestyles (fitness, diet), gender identity, sexual health, and mental health issues from online websites, social media platforms, wearable self-tracking apps, and other adolescents within online communities [10,11]. However, adolescents are less accepting of online or wearable apps that require them to input information [7]. Overall, online media and social media apps are seen as simple to use, unidentifiable, and impartial sources of health information by adolescents [7,12]. Health-related stories from peers are particularly valued among adolescents [7,13]. Influencers on social media, adolescents who create content, and microcelebrities are increasingly important resources for health-related information and social support [7,14-16]. However, adolescents may find the sheer volume of online information challenging and are not always confident in their ability to discern accurate information from misinformation or disinformation [7].

Social media platforms that are based on the creation of visual media, such as TikTok, are popular with adolescents. TikTok, a video-based social media platform, has been leveraged as a way to disseminate health-related information, and this has been especially visible during the COVID-19 pandemic [17]. The vast reach of TikTok worldwide offers a unique approach for disseminating information to the millions of users ranging from children to adults. As a social media platform, TikTok creators combine music and dance attached to personal messages that are widely disseminated [17].

Several studies have been conducted on the health-related content on TikTok. These studies indicate that a wide range of issues have been examined, including health promoting and compromising issues. Examples include, but are not limited to, studies related to COVID-19 mitigation, eating disorders, vaping, climate change, and equity issues [12,18-26].

Specific to mental health information and social support, researchers determined that youth and young adults appreciated shared experiences within online discussion forums, citing accessibility, anonymity, inclusivity, sense of control, and mitigation of stigma as valued resource characteristics [12]. Preference for seeking health information online or through peer-to-peer sharing can reflect individuals’ concerns or experiences with nonaffirming or discriminatory health care providers [12]. Furthermore, peer-to-peer health information sharing may fill the gaps in social support from health systems, health-specific information, and insight into “how to live” with chronic diseases including mental health. In particular, select TikTok videos may serve as relevant educational resources for health care professionals’ education and training [12]. However, research exploring mental health content on TikTok is essentially absent from published research literature.

Online social media networks provide valuable opportunities to connect with each other to share experiences and strategies for health and wellness, such as meditation, mindfulness, stress relief, and those specific to mental health conditions [13]. Mental health issues are highly prevalent in adolescents. According to the World Health Organization, “globally, one in seven 10-19-year-olds experiences a mental disorder, accounting for 13% of the global burden of disease in this age group” [27]. Given these statistics, combined with the popularity of TikTok use in this age group [28], the aim of this study was to describe the content of the hashtag #mentalhealth on TikTok.

Overall, the 100 videos studied received 1,354,100,000 views; 266,900,000 likes; and 2,515,954 comments. On average, each video received 13,406,930.69 (SD 8,728,095.52) views; 2,657,425.74 (SD 1,449,920.45) likes; and 24,910.44 (SD 21,035.06) comments. Of the 100 videos, a majority (n=84, 84%) were classified as consumer-generated; only 13 (13%) were classified as influencer- or verified-user–generated, with the remaining classified as heath care professional–generated (n=1, 1%), television- or internet-based news (n=1, 1%), and television-based entertainment (n=1, 1%).

In Table 1, the first column lists the 14 different content categories of the video data and the second column details how many of the 100 videos sampled included this content. The table also includes the number of views, likes, and comments that the videos with these particular features garnered. Relative percentages from the total are included as well. The content category “statistics and prevalence of mental health disorders or issues” was omitted from the table since it was not featured in any of the sampled videos.

The only content category observed in a majority (51/100, 51%) of the videos sampled was “general mental health.” The remaining content categories appeared in less than 50% of the sample. “Personal experience” was the next most prevalent category observed in the videos and it appeared in 40% (40/100) of the sample. The remaining content categories appeared in less than 20% of the sample, with the following 5 content categories appearing in less than 5% of the sample: anxiety or fear, physical health conditions or variables, stress, mental health stigma, and missing other people or connections due to COVID-19.

Table 2 provides information about the themes noted in the videos’ comments. This table shows 6 different themes, the number of videos with comments that reflected these themes, and the associated number of views, likes, and comments of these videos. The most common themes observed in the videos’ comments sections were “offering support or validation” (61/100, 61%) and “describing other mental health issues or struggles” (49/100, 49%).

In total, 32% (32/100) of the videos sampled received more than the overall average number of likes (ie, more than 2.67 million likes). Among these 32 videos, 23 (72%) included comments offering support or validation and 20 (62%) included comments describing other mental health issues or struggles. The remaining themes were included in ≥10 videos: shared coping strategies, experiences of healing, or ways to feel better (10/32, 31%); describing an experience with hospitalization for mental health issues (7/32, 22%); mentioning experiences with suicide or suicide ideation (6/32, 19%); and mentioning experience with self-harm (2/32, 6%).

The frequently used words excerpted from the comments section of the TikTok platform are shown in Multimedia Appendices 1-2. Multimedia Appendix 1 shows the negative sentiments portrayed in the comments that reflect serious mental health concerns, which were expressed in response to participant-posted TikTok videos depicting issues of depression, grief, sadness, anger, loneliness, and trauma. In contrast, Multimedia Appendix 2 shows social support and collective optimism in the comments about the posted TikTok videos. These comments were caring and reflected encouragement, praise, and acceptance. It is important to note that these comments were generally presented in the context of support from those who allegedly have shared experiences or trauma.