I think suicide prevention might be an underrated cause (need to firmly fact check before my confidence in this is high)
(1) if you delay someone from commiting suicide for just 30 minutes they will almost always change their mind
(2) suicidal people usually spend years inbetween attempts
(3) after someone "fails" a suicide attempt via changing their mind they usually feel a lot better emotionally (excluding failed attempts, only failure via changing your mind)
a charity in the UK places 1 hour of phone time is £44, if we assume 10% of people who call the suicide hotline are both (a) going to commit suicide (b) do not because of that call (which would take around 30 minutes) we can assume every 5 hours results in one suicidal person not killing themselves and feeling relief for either months or years - this would put the price of possibly stopping someone from killing themselves at £220 (though it doesn't mean you would save an entire lifespan) suicide is also somewhat unique in that not only does it lead to mourning a loved one but often leads to self blame and all types of emotional problems in the loved ones.
Hey! You might be interested in this forum post on suicide hotlines from a while back. https://forum.effectivealtruism.org/posts/Xh5oyGkngGjCmNhcP/how-impactful-is-being-a-suicide-hotline-volunteer
Unfortunately, I think the comments in the post (including one from a former volunteer) make a really compelling case that it takes a lot more than 5 hours to prevent a suicide. I think it takes at least hundreds and probably thousands of hours of calls.
You might be surprised to learn that CEAs of mental health interventions in the EA space (example) don’t count the value of preventing suicide and self-harm. But on a DALY basis, self-harm and suicide have roughly the same burden in total as depression as a whole, precisely because they’re so much worse (this is to say nothing of effects on income).
I think that mental health interventions, and especially direct suicide counselling, might be really underrated, simply because the research hasn’t been done in a lot of depth (that I’m aware of). Part of this is because it’s quite hard to accurately quantify the effects of interventions on long-term suicide rates (you need many years, and access to death records). However, there are a few good studies that I think might point to ways this could at least be estimated, and then we can agree on an appropriate evidence discount.
The theory of change gets quite convoluted. For example, people may report feeling suicidal or having suicidal thoughts, but this may have no real correlation with their attempts. Or we may find that people who report feeling less suicidal commit suicide less often, but it may not be true that reducing their feelings of suicidality actually has any effect on their long-term attempt rate.
Here’s a good paper looking at 84,000 people’s PHQ-9 scores and follow-ups with suicidality. Unfortunately, the evidence isn’t causal, but this study looks at suicide prevention RCTs and finds that, at least, depression interventions reduce ideation, but not suicidality. I’ll be doing a bit more research in this area because I think it’s quite promising!
I think it's possibly donating food directly to homeless people might be a viable way to save a life (I've not done any fact checking or math so keep that in mind) I was recently speaking to a homeless person and the topic of starvation came up and he alleged that "homeless people don't die from starvation but a lack of food kills them" basically saying that secondary effects lead to the death such as using more drugs when food is scare, likely having bad immune system due to low quality food/not enough calories - basically not enough food doesn't kill them but it starts a downward spiral that does - I'm not saying this is a perfect cause but given how much of a bias people have to seeing the people they help and given that most people are becoming cashless i.e homeless people have less money, buying homeless people a bit of food as a habit when you see them might lead to a (higher than expected) number of lives saved in a way most people could probably be convinced of (outside of EA spaces even convincing someone to give is difficult) it also bypasses the "homeless people will just spend it on drugs" issue people often cite as why they don't give money to the homeless
Hey! You might be interested in this forum post on suicide hotlines from a while back. https://forum.effectivealtruism.org/posts/Xh5oyGkngGjCmNhcP/how-impactful-is-being-a-suicide-hotline-volunteer
Unfortunately, I think the comments in the post (including one from a former volunteer) make a really compelling case that it takes a lot more than 5 hours to prevent a suicide. I think it takes at least hundreds and probably thousands of hours of calls.