COVID forced us to talk — a lot — about Americans' deteriorating mental health. Four years later, the scale of the problem hardly appears to have gotten better, in large part because the system (perhaps unsurprisingly) remains ill-equipped to do much about it.

Why it matters: The complexities of mental illness, stressors of modern life and a dearth of straightforward solutions present barriers that we don't really even know how to start climbing.

• And in most cases, problems stuffed under the umbrella of mental health won't be solved by the health care system alone.
• "We've gotten better at measuring the extent of mental health problems ... but we do not have good strategies for addressing a lot of them," said Sherry Glied, dean of NYU's Robert F. Wagner Graduate School of Public Service.
• "It's not like we have a pill and we're not giving it to people. We don't know what to do," she added. "The stuff that we are doing doesn't seem to have much effect. Maybe it has some effect, but it's not great, for sure."

Where it stands: The post-pandemic era has featured the stubborn persistence of the youth mental health crisis, emergency rooms swamped with psychiatric patients and greater openness to heavy-handed policy approaches to the most severe manifestations of mental illness.

• At the same time, social connectedness has deteriorated and the U.S. hit an all-time low ranking in the annual World Happiness Report this year.
• Nearly a third of U.S. adults report feeling lonely at least once a week, and 10% say they are lonely every day.
• There's a clear link between loneliness and poor mental health, and U.S. Surgeon General Vivek Murthy has been outspoken about the "epidemic" of loneliness and isolation.

Between the lines: Turning the corner on a problem as large and nebulous as America's mental health crisis will be a monumental task.

• But in some areas we're spinning our wheels while in others we're throwing partial solutions at problems that won't get better without holistic solutions, including much greater societal investment in social supports.
• Regardless, the status quo isn't working.
• "We've expanded access to care enormously over time, and we've got a lot more mental health practitioners than we ever did before, and that does not show up in any measures of people's well-being," Glied said. "Even though we know individual people get benefits from this … from a population level, this intervention has not had a big effect."

The other side: Increased attention to a mental health crisis that Americans view as a top threat to public health has also brought new urgency and new ideas.

• "I think we're trying new stuff. The places where I would expect some opportunities for better outcomes are around the way we handle mental health crises — we're putting in more money, we're putting in more technology, we're doing it in new ways," said Richard Frank, director of the Brookings Institution's Center on Health Policy.
• "I have seen more investment in the last three years in mental health — from the perspective of expanding access to services and investments in prevention — than I've seen in nearly 30 years that I've been in public health," Murthy told me at last week's Axios event.

What we're watching: New drugs may offer more options for patients stuck mostly with decades-old therapies, and there's growing awareness that better understanding the biology of mental illness will help find and match patients to treatments.

• But the population most in need of more effective treatments is increasingly caught up in a growing wave of public intolerance for homelessness, public drug use or erratic behavior on the streets.
• That's opened the door — in even the bluest of states — to shifting more of the mental health crisis response onto law enforcement, without commensurate increases in resources for treatment or social supports.
• "If you're trying to get people out of public spaces, that might work," said Keith Humphreys, a Stanford University psychiatry professor. "But that doesn't solve the problem of the person's illness."

Talking about America's mental health crisis, in some ways, isn't helpful: It obscures the reality that it's made up of several distinct problems that are all either growing or have become much more visible.

• But they can compete with one another for the same limited resources, and a problem that may fit in one category at a certain phase of someone's life may evolve into something different later.

Why it matters: The various manifestations of the mental health crisis have different solutions, to the extent we know what to do about any of them, experts say.

It helps me to think about mental health in buckets. Here are a few that I use:

1. The youth mental health crisis: This was happening before the pandemic, but COVID and all of its disruptions clearly exacerbated the trend.
2. Serious mental illness: This includes disorders like schizophrenia, bipolar disorder and chronic depression, which are often disabling.
3. More general mental health disorders: This includes conditions like anxiety and depression — which exist on a spectrum of severity.
4. Substance abuse and addiction: More on this next week!

Zoom in: The share of the population with a serious mental illness has generally held steady over time, experts told me.

• But conditions like anxiety and depression are becoming much more prevalent amid challenging societal changes.
• "Depression and anxiety are much easier to generate entirely with the environment. You can be very lonely and have a stressful job and an unsuccessful marriage, but you won't become schizophrenic from that," said Stanford's Humphreys.

Between the lines: More people are being connected to treatment, but that hasn't really changed the overall mental health burden. Part of the issue is there's just not enough visibility into the quality of care that people are receiving, experts said.

• "What would make the big change ... is taking all this money that we spend right now and all the people we throw at the problem and make sure that they put the best science and the best use of those monies to work to make people's lives better," said Brookings' Frank.
• "And that means you do things that are somewhat different for kids and people with serious mental illness … and people with run-of-the-mill depression and anxiety get treated in still a different way."

Disentangling how much of the U.S. mental health crisis comes down to unhappiness or loneliness is nearly impossible, but the overlap has profound implications for the mental health system.

Why it matters: There will never be enough formal health care to address what may be at its root a societal problem.

The big picture: "People are not happy in the world today. That seems to be true all around the world. The world has changed a lot underfoot and people don't know how to deal with that," NYU's Glied said.

• "The distinction between poor mental health and unhappiness is a pretty fuzzy barrier," she added.
• And in some ways, this may be a distinction without a difference. But in others, there's a big difference, especially when it comes to involving the medical system.
• "The question that I always think of in my head is, 'Is this a condition where if I gave you a pill for it, you'll feel better?'" Glied added. "I do worry that medicalizing this may divert resources from the places where they might be more useful."

State of play: "Loneliness definitely increases people's risk of depression and anxiety. It even shortens life expectancy. So it's an epidemic," Humphreys said. "COVID definitely made it worse."

• Anyone who lived through the pandemic understands why it was such a lonely time. Infection prevention, by definition, meant not being around other people in real life.
• And while social distancing rules are long gone, the pandemic's lasting negative impact on social connectivity is particularly evident in young people, who lived through its isolating effects during formative phases of life.

The bottom line: The mental health system, which is already notoriously short-staffed and difficult to access, can't on its own bear the weight of the loneliness epidemic.

• "With people who are not on the psychotic spectrum, yes, we want to have mental health services available, but we can't therapy our way out of the problem," Humphreys said.
• "A therapist can certainly ease some of the sting of loneliness, but that's just not a solution at a social level."