What's that status of research into curing (as opposed to treating symptoms of) mental illnesses?

I know several people who have been in and out of mental health treatment for years. What’s the status of research into medical procedures, drugs, etc. that cure mental illness to the point where it doesn’t recur when treatment ends, as opposed to treating symptoms that recur if treatment is stopped? E.g. instead of Joe taking 1 pill a day for depression, he could undergo some “curative” treatment that, when finished, would leave Joe without any mental illness and without the need for further treatment.

Is this difficult to push forward due to the heavy financial benefits psychiatrists and drug manufacturers get from repeat patients? E.g., worries that Dr. Bob, Psychiatrist, will go bankrupt if all his regular Depression and OCD patients try a new cure and stop seeing him for regular visits and prescription refills because their conditions are cured?

The curative treatment could be of any form, whether drug, talking therapy, surgery, etc.

As far as this bit is concerned pharma companies are about a million miles away from being able to weigh things up like that. That sort of calculus no doubt takes place in areas like antiinfectives, or tropical disease, say, but the challenges in CNS treatments are just at the level of basic scientific understanding.
There has been a mass-exit of big pharma out of CNS in the last few years for this reason.
The area is made a lot more difficult in that in vivo data is a nightmare - e.g. what exactly does a depressed dog look like, and how does he look after he’s taken our candidate drug?
If you look at the in vitro data from some of the more successful drugs, they’re often really dirty (in pharmacological terms) and hit several CNS receptors. This is discouraging from a drug design point of view, as it’s hard to form hypotheses that can cover such a wide number of targets in the brain.

That’s just the drug perspective - as you say there are many other approaches. For pharma, I think the area is always going to be a fundamentally attractive one both economically and scientifically, but it’s kicked their arse for a few years now and is on a downswing in the industry.

No

Mental illness is a pretty broad term.

Part of the problem is that (like for example artificial intelligence) a lot of times, when a physiological cure is found for a mind-affecting illness, the illness is no longer classified as mental illness.

To be considered “mental illness” a problem may need to be uncurable (though possibly treatable) via physical or chemical means.

Otherwise, you could potentially consider depression caused by a brain tumor or Lyme disease as curable (by removing tumor/antibiotics respectively) for example

Desensitization therapies for specific phobias might qualify as “cures.”

Historically, yes, sort of. The most common way of treating “mental illnesses” is to administer chemicals. The official word is that the chemicals being used are suposed to directly address the psychiatric ailment it is prescribed for, but, historically, if someone ever actually figured out a physiological cause of the condition, the disease has tended to get recategorized as something OTHER THAN a mental illness. The result is that ailments designated as “mental illness” that remained in that category have tended to be the ones for which a clear-cut medical etiology and intervention have NOT BEEN FOUND.
So the first issue with “curing” any of the (remaining) “mental illnesses” is that they are badly defined to begin with. We don’t understand what they “are”. It is only a persistent theory that they have something to do with brain chemistry, or at any rate MORE to do with brain chemistry than your own current mood and thoughts and aspirations and behaviors do. There’s very little evidence for “chemical imbalances in the brain” existing in any fashion that can be correlated with psychiatric diagnosis, aside from those caused by psychiatric pharmaceuticals themselves. In practice (as opposed to theory), a psychiatric diagnosis is about a person’s behavior, subjectively interpreted, with a very wide leeway for making that determination.

Yes, this is the problem - we have NO IDEA what causes mental problems. The idea that it’s childhood trauma is as much a Hollywood shortcut as anyting else. Schizophrenia, for example, seems to be a case that something builds and builds in the body until it goes “snap” and the person loses contact with reality, hears voices and thinks that aliens or the giant walking trees are following them… It seems obviously physical - yet we don’t know why it happens. Similarly, post-partum depression is something with an obviously physical cause, yet we don’t know what drugs to counteract the problem other than the usual primitive mind-altering ones.

Until we can nail down WHY, we cannnot nail down HOW.

It’s not a case of keeping a gravy train going; it’s just that most brain doctors are no more advanced than the quacks of the early 1900’s; They find something that seems to work sometimes, and if it doesn’t work try the next thing. They treat symptoms because that is all they know how to do. We don’t know what really causes/tiggers autism, epilepsy, Parkinsons, dyslexia, bipolar, or many other diseases. We have a long way to go.

Since mental problem are difficult to monitor in lab animals, all the doctors can do is play with live human patients. Their range for experimenation is limited. That is why progress is so slow.

The same is true for a whole lot of purely physical illnesses, too.

Diabetes, high blood pressure, elevated cholesterol, etc. are all treated with drugs, which patients usually take for all the rest of their life. So controlled, but not ‘cured’.

Do you think Dr. Bob actually has clout?

Many mental disorders have a biological basis. Just looking at the brain of a schizophrenic person will show large morphological changes. And someone with depression may, for one reason or another, have serotonin or norepinephrine receptors which do not receive the neurotransmitter efficiently, or they don’t produce enough. Antidepressants work by adding a substance which “tricks” the nervous system into thinking that it’s getting a lot of neurotransmitters. Unless you can find a way to selectively replace these proteins, you can’t “cure” it. Perhaps the best way to cure many mental disorders is by doing things prenatally, or even screening the parents for what they might pass on.

There are surgical treatments for some neurological conditions.
Sometimes a lesion may be removed, or the corpus callosum may be cut. There’s little overlap however between the kinds of condition that is treated in this way and what is normally considered “mental illness” as surgery remains risky and is only performed for life-threatening and incapacitating conditions, such as severe epilepsy.

Alternatively, a probe (sometimes called a “brain pacemaker”) can be placed in the brain which can increase or decrease the relative activation of a part of the brain. This is less risky, because if the probe is placed incorrectly it can be repositioned or simply turned off.
This technique (which is called deep brain stimulation) has been used to treat severe depression. I don’t know whether you would consider it a permanent treatment however; if the device is turned off, the condition returns.

Incidentally, the main reason that surgery is risky is because the precise layout and “wiring” of everyone’s brain is different. So with any incision there’s a risk of damaging an important function.