Personally, I think it's a bit hasty because we're not sure if it will do more harm than good. Ideally, they would have piloted this in a smaller region first but that probably wasn't feasible politically.

Ferguson (2024) is a meta-analysis of 27 experimental studies that finds causal effects are statistically no different than zero (but with significant heterogeneity). 

Haidt & Rausch criticised Ferguson's methodology on their blog and this sparked much debate. They argue that many of the studies only capture withdrawal symptoms and don't follow subjects long enough to get past that stage and onto more positive experiences. 

Another good study makes use of a natural experiment by looking at changes in student wellbeing at US universities in the early years of Facebook's gradual roll out. 

I'm not aware of any governments blocking experimental studies. Policymakers are desperate for better evidence to inform their regulatory decisions. Despite the ongoing debate among researchers, Australia are going full steam ahead and recently announced a ban on social media for all under-16s.

Maybe you should have a separate debate week on the most appropriate name for the "global health" cause area ;o)

Thanks Toby! Health is part of wellbeing, so "global wellbeing" would be sufficient. 

However, it's worth noting that "global wellbeing" should apply to all moral patients, whereas "global health" is usually understood as a human-specific set of interventions.

It would be better to call this: Animal Welfare vs Human Welfare Debate Week

When your scope extends to "any intervention which primarily aims to increase the wellbeing of animals, or decrease their suffering, and...the same for humans”, the term "global health" only represents a sub-set of possible interventions.

Welcome to the forum! Thanks so much for taking the time to dig into this question and sharing your findings. The treatment gap in global mental health is enormous and apps are an essential tool for addressing this challenge. 

I didn't have time to review your calculations in detail, but I have a few general reflections that may be useful.

1) There is a brand new meta-analysis on the efficacy of mental health apps which includes 176 RCTS (Linardon et al, 2024). They conclude that "apps have overall small but significant effects on symptoms of depression and generalized anxiety, and that specific features of apps – such as CBT or mood monitoring features and chatbot technology – are associated with larger effect sizes."

2) There is a substantial difference in efficacy between self-help and guided self-help apps. Kaya Guides (incubated by Charity Entrepreneurship) is using WhatsApp to pilot the WHO's guided self-help intervention in India. Their founder wrote an excellent summary of their work here.

3) Be careful with using a single WELLBY number for AMF. The wellbeing effects of life-extending interventions vary widely depending on philosophical choices, so it is better to use the range of possible outcomes rather than a single figure (see The Elephant in the Bednet).

4) John Torous is a leading researcher and thought leader in digital mental health. If you'd like to spend more time learning about this topic, I recommend looking at his recent publications.

5) The current market for mental health apps is completely unregulated and there are major concerns about privacy and data protection. Wellcome recently awarded £1.8m to MHRA and NICE to explore how the market could be regulated more effectively to protect patient safety.

You may be interested in this recent meta-analysis on the efficacy of mental health apps. The authors conclude that: "apps have overall small but significant effects on symptoms of depression and generalized anxiety, and that specific features of apps – such as CBT or mood monitoring features and chatbot technology – are associated with larger effect sizes."

This comment helps to highlight the importance of language when discussing this topic. Happiness and wellbeing are not the same thing and it can lead to confusion when the two terms are used interchangeably.

This post explains the three main theories of wellbeing: hedonism, desire-based views, and objective list views. If you're a hedonist, then failing to optimise for happiness would be a mistake. However, as Owen points out, people often trade off happiness for other things they value which is more consistent with the objective list theory.

Over recent decades, the field of wellbeing science has settled on 'life satisfaction' as the primary metric for subjective wellbeing. It's still important to track other measures too (e.g., positive/negative affect, sense of meaning/purpose), but I share the view that life satisfaction should be the goal of society. 

That's because life satisfaction is the common unit that people use when they make trade-offs between happiness, purpose, duty etc. It's the 'all things considered' assessment of a person's life, according to what they value. Many attempts to measure wellbeing rely on a dashboard of indicators, but in all those cases, the relative weightings of the indicators are decided by the researchers rather than the subjects of the research and, in my view, that misses the whole point. Having said that, I've read some compelling arguments against the life satisfaction approach from Plant (2023) and Thoma (2021) which readers may find insightful.