I wouldn't say there's "a lot" of funding. Mental health research is significantly underfunded compared to other health conditions. More info in this report

BD² has committed $105+ million to research on bipolar disorder in recent years. It's funded by the Sergey Brin Family Foundation and three other philanthropic investors. For anyone interested in funding bipolar research, this would be my recommendation.

Mental health is one of Wellcome's three strategic priorities. They've funded a lot of impactful research on SMIs, including AVATAR therapy for psychosis (as highlighted by Kestrel) and the first new drug for schizophrenia in 30 years.

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.

It's fair to say that the evidence is mixed at the moment. Jonathan Haidt's The Anxious Generation  has captured a lot of attention, but many researchers dispute his arguments. This episode of the Freakonomics podcast provides a balanced perspective with voices from both sides of the debate.

There are many competing theories for the decline in youth wellbeing in Western countries (trends in other parts of the world are different), but they're mostly based on correlational evidence; causal evidence is weak and limited.

Some studies I recommend are:

“The Declining Mental Health Of The Young And The Global Disappearance Of The Hump Shape In Age In Unhappiness,” by David G. Blanchflower, Alex Bryson, and Xiaowei Xu (NBER Working Paper, 2024).

“Further Evidence on the Global Decline in the Mental Health of the Young,” by David G. Blanchflower, Alex Bryson, Anthony Lepinteur, and Alan Piper (NBER Working Paper, 2024).

“To What Extent are Trends in Teen Mental Health Driven by Changes in Reporting?” by Adriana Corredor-Waldron and Janet Currie (Journal of Human Resources, 2024).

“Global Well-Being and Mental Health in the Internet Age,” by Matti Vuorre and Andrew K. Przybylski (Clinical Psychological Science, 2023).

“Are Mental Health Awareness Efforts Contributing to the Rise in Reported Mental Health Problems? A Call to Test the Prevalence Inflation Hypothesis,” by Lucy Foulkes and Jack L. Andrews (New Ideas in Psychology, 2023).

“The Association Between Adolescent Well-Being and Digital Technology Use,” by Amy Orben and Andrew K. Przybylski (Nature Human Behaviour, 2019).

Social Media and Adolescent Health (Consensus Study Report)

What do we know about mental health and the internet in young people? (MQ Mental Health Research)

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."