Background

The internet has made rapid and dramatic changes to society. It has altered the way we communicate, form groups, gather and process information, develop relationships and spend our leisure time. On average we spend 1 min in every 12 of our waking life connected to the internet, and this year 25% of the world's population will use a smartphone. ¹ Contemporary psychiatry has failed in its duty to keep pace with these changes.

There is an insufficient evidence base to reliably appraise the internet in terms of specific harms and benefits to mental health and this limits our understanding of the potential for using it for mental health promotion and secondary or tertiary prevention. Here we describe the available evidence, discuss what can be learned from other areas of health promotion research and make recommendations for further research.

Digital mental health promotion

Research in mental health promotion has tended to focus on issues such as reducing stigma, reviewing lifestyle factors, enhancing socialisation and improving mental health awareness using non-digital approaches. ^{Reference Kalra, Christodoulou, Jenkins, Tsipas, Christodoulou and Lecic-Tosevski2} These key components of mental health promotion need to be transposed to, and adapted for digital media. Similarly studies of the lived environment, which continue to concentrate on access to green space, good-quality housing and face-to-face contact ^{Reference Powell, Hamborg, Stallard, Burls, McSorley and Bennett3} must begin to examine the possible impact of virtual worlds: Facebook friends, Twitter retweets and Instagram likes.

A systematic search of one database (Medline) using appropriate MeSH headings and keywords (psychiatry OR mental health OR mental disorder, AND health promotion, AND digital OR internet OR software OR computer communications network OR online systems OR computers) reveals the paucity of evaluation in this area. Electronic cognitive–behavioural therapy (eCBT) interventions have been more widely appraised and are excluded here (although some of these may have components of secondary or tertiary health promotion imbedded within them). Of 258 articles published before the end of March 2015 only 32 studies evaluated novel digital interventions, and only 9 of these used randomised controlled methods. Of these trials, five had outcomes relating to mental well-being, ^{Reference Morgan, Jorm and Mackinnon4–Reference Cunningham8} three measured knowledge of and reduction in drug and alcohol use, ^{Reference Ondersma, Svikis and Schuster9–Reference Leung, Ma and Russell11} and 1 reported healthy eating outcomes in eating disorders. ^{Reference Portnoy, Scott-Sheldon, Johnson and Carey12} Other articles identified in the search explored how individuals access mental health information and advice. Many articles focused on specific subgroups, particularly younger people.

Two systematic reviews have investigated the effectiveness of internet-based programs and specially designed software packages to achieve behaviour change in areas such as sexual health, smoking cessation and healthy eating, which could be considered within the wider remit of mental health promotion. ^{Reference Webb, Joseph, Yardley and Michie13,Reference Allison, Bauermeister, Bull, Lightfoot, Mustanski and Shegog14} These reviews demonstrate the potential for the internet to be used as a tool for engagement with traditionally hard to reach groups, especially younger, minority groups who experience stigma. The target audience for mental health promotion, and secondary and tertiary prevention, shares some of these characteristics and it may be possible to extrapolate from these findings. In these areas, some of the key elements of digital technologies have been positively appraised: effectiveness, cost–benefit, ability to provide standardised information in a tailored manner, interactivity, privacy, autonomy and portability. ^{Reference Powell, Hamborg, Stallard, Burls, McSorley and Bennett3} Recent reviews have also summarised evidence for eCBT in secondary prevention ^{Reference Musiat and Tarrier15} and electronic games as a method of delivering therapy. ^{Reference Horne-Moyer, Moyer, Messer and Messer16} Although these digital approaches are popular among certain subgroups, with high acceptability ratings, there is still a need to rigorously test digital interventions against ‘real-world’ outcomes.

Potential harms of internet use

To fully appreciate the potential for digital health promotion we need to more comprehensively understand the harms and benefits of internet use, particularly if this usage has a differential impact on subgroups. The press has speculated that certain aspects of the internet may be directly detrimental to mental health, ^{Reference Swain17} but good-quality research in this area is sparse.

Some ‘real-world’ risk factors for poor mental health exist in a concentrated form on the internet. Pro-anorexia websites are postulated to be more harmful than traditional media because they include both extreme pro-anorexia content and peer encoragement. ^{Reference Juarez, Soto and Pritchard18} Similarly pro-suicide and self-harm websites provide discussion boards and information about high-risk methods that might have previously been inaccessible. Studies of people with histories of offline victimisation show that these individuals are at increased risk of online bullying and sexual solicitation. ^{Reference Allison, Bauermeister, Bull, Lightfoot, Mustanski and Shegog14} Online gaming, gambling, pornography and generalised high-volume use have all been identified as risk factors for poor mental health. ^{Reference Frangos, Frangos and Sotiropoulos19,Reference Kraut, Patterson, Lundmark, Kiesler, Mukophadhyay and Scherlis20}

A particular area of concern is the lack of clarity over the impact that online relationships have on socialisation. We know that social isolation is a predictor of poor mental health and that belonging to multiple social groups can be protective against the potential mental health effects of significant life events, such as bereavement or physical health problems. ^{Reference Wills, Ainette, Baum, Revenson and Singer21} However, it remains unclear whether sites like Facebook augment or replace offline social networks. The ease of joining or leaving many online groups and the transitional nature of social network sites would suggest that they might provide less reliable support. Conversely social networking sites could provide support for those who find it hard to form or sustain offline relationships, offering an opportunity to communicate with individuals with similar lived experiences, regardless of geographical proximity. Age may be an important mediating factor when addressing questions such as this, as some studies suggest that digital natives (those born after digital technologies became commonplace) are more likely to find the internet prosocial. ^{Reference Huang22}

The internet allows individuals to access vast amounts of information about mental health without clear indications of provenance or quality. This access to information can fuel medicalisation and healthism, potentially pathologising the problems of everyday life. This is a common criticism of strategies for health promotion that focus on an individual's responsibility for self-management of their health. ^{Reference Korp23} Access to (mis)information can also complicate secondary and tertiary prevention, and doctors may need to learn to confront this explicitly in the consultation.

Putative benefits of internet use

Despite the concerns discussed, it is likely that the internet has many potential benefits that could be harnessed for mental health promotion and illness prevention. As a tool for individual empowerment it can educate, reduce stigma, signpost resources, access hard to reach groups, provide patient and carer support groups, and potentially encourage more emotional expression and self-reflection. ^{Reference Barak and Grohol24}

The Royal College of Psychiatrists' website provides detailed information for patients about mental health conditions, and has an online learning module on ‘effective use of the internet’. ^{Reference Theodosiou and Sweeney25} This covers some of the broad impacts that the internet could have on mental health. It has also issued guidance for clinicians that young people should be asked about their online lives during assessments following self-harm, and that they should be directed towards recovery-oriented websites. ²⁶ Although we welcome this advice, we feel that it does not go far enough and that all mental health assessments require engagement with an individual's ‘online life history’. Other professional bodies appear to lag behind in their understanding of how digital technologies have integrated into daily life. For example, in the UK, NHS online, as its first step towards mental wellbeing, encourages people to ‘connect’ suggesting we should ‘switch off the TV tonight and play a game with the children, or just talk’. ²⁷ With more people watching television programs online, playing multiplayer online games and talking via webcam, this advice, and the evidence on which it is based, is already outdated.

Implications for future research and practice

There is a need to quantify the impact of the internet on mental health and to begin formulating approaches to mental health promotion that are relevant to the digital age. We need to measure the digital usage and fluency of at-risk groups, levels of digital inequality and the associations between specific mental health conditions and internet and social media use. Research is also needed into the effectiveness of online information seeking, the use of online peer support groups and the acceptability of digital applications in engaging with target populations. Following this, the effectiveness of targeted or population-wide interventions can be considered. As discussed, these interventions are likely to include modified versions of traditional health promotion approaches, eCBTand other electronic therapies, electronic games, online peer-support networks and user groups. As the scope and the manner in which digital technologies are used changes very rapidly, reviews in this area need to be regularly updated to remain relevant to researchers, clinicians, patients and the public.