Saturday, December 5, 2009

Me, Apollo 15, and the Future

The following is a continuation of Me, Captain Ahab, and the Anterior Cingulate Cortex:

The year - 1971. Location - the moon. After 23 hours with no sleep, Apollo 15’s two moonwalkers were back in their command module in lunar orbit, preparing for their return home. Back in Houston 240,000 miles away, ground controllers picked up anomalous EKG readings from one of the astronauts. Jim Irwin’s heart was skipping a beat, then beating twice rapidly. After communicating with Irwin, the flight surgeon at Mission Control diagnosed a specific type of heart arrhythmia known as bigeminy.

Had Irwin been on the ground, doctors would have treated him for heart attack. But it turned out that the command module, with a 100 percent oxygen atmosphere and zero gravity, was better than any ICU he would have been placed in on earth. His heart soon settled back to normal, and Apollo 15 later successfully splashed down without incident. A few months later, Irwin had a heart attack. Twenty years later, yet another heart attack killed him.

Fast forward to the present. Location - earth. An individual very close to me was admitted to a psychiatric unit, and, after careful evaluation, was diagnosed with depression and given an antidepressant. Following a second hospitalization, he was put on different meds and released. Soon after, he was back in the hospital.

Basically, this individual has broken brain disease, and if we knew exactly what part of the brain was broken and could link the malfunction to the symptoms he was experiencing, we would have an exact term for it and perhaps have a clue of how to best treat it. But diagnostic psychiatry in 2009 is no match for the diagnostic cardiology of 1971 - at least not right now it isn’t.

Part of what is holding us back is that mental illness is far more complex than cardiac illness. What brain scans are showing is something akin to a total system collapse in the brain, involving many interconnected brain regions, rather than a specific fault. The brain science is beginning to tease out subtle structural and functional distinctions across a range of diagnoses. But this is hardly equivalent to taking an X-ray, finding a bone fracture, and knowing exactly how to set the break.

Nevertheless, brain scans are providing us with a sneak preview of the future. In a famous set of experiments performed two or so decades ago, OCD subjects (ones obsessed with cleanliness) shared a brain scan machine with a "dirty" sweat sock. Their respective brain loops lit up like a Christmas tree. When exposed to a "clean" sock, their brains quieted down.

The anterior cingulate cortex (ACC), part of the mid-brain, contains specialized neurons responsible for “gating.” which allows the brain to focus on certain incoming information (such as a conversation) while tuning out others (such as the background hum of an air conditioner). When things go wrong in the ACC, all manner of bad things can happen, such as OCD or schizophrenia or depression.

Thanks to this knowledge, doctors were able to adapt deep brain stimulation (DBS), used for Parkinsons, to experimental (and still extremely rare) psychiatric surgery. In Feb this year, the FDA approved DBS as a last resort treatment for OCD. The procedure also shows promise for depression. In DBS, a metal lead is inserted through folds in the brain. An electric pulse breaks up neuronal signals (such as those responsible for distracting thoughts and ruminations) in the ACC region. Unlike earlier generations of brain surgery (such as cingulotomies) no surgical lesions are involved. The surgery is reversible, but does involve risk.

Let’s be clear on this: This is not a piece extolling the virtues of psychiatric brain surgery. Indeed, it is difficult to imagine psychiatry headed in this direction. But what we are witnessing nonetheless presents us with a tantalizing peak at what tomorrow may involve, namely:

It is foreseeable that advances in technology will make MRI machines, or some other brain scan technology, convenient and affordable and routine, equating to advances in computer technology.

In the meantime, we already have the means to do gene scans - the chips are getting faster every year. Now imagine the software to interpret data coming from a whole ranges of sources - gene scans, brain scans, psychiatric evaluation, neurological testing, etc - to give the treating psychiatrist a range of options to consider.

The following is wild speculation: Keep in mind that the dominant operating paradigm for mental illness is system breakdown, a host of things going wrong seemingly all at once. But suppose we could get a bit closer to the source - say the hippocampus (involved in memory) failing to boot up, say key parts of the frontal lobes going off-line, say certain stress pathways overloading. Say we were able to pinpoint various signaling bottlenecks and hubs.

Thus, depression is no longer just depression. In fact, once we get a true read on what is going on, we may call its manifold variations something entirely different. All this would suggest targeted treatments and therapies, even with today’s highly imperfect remedies. Perhaps a dopamine enhancer to kickstart a certain brain system rather than an SSRI. Perhaps talking therapy focusing on past trauma rather than directed at here and now challenges.

The long-term pay-off would be that this kind of knowledge would spur future drug development (namely smart meds) and further refine talking therapies. It could also open the way for pinpoint electrical therapies and who knows what.

Private investors would need to see the solid science - a clear idea of how to get from A to B to C - before they were willing to put their money on the line. The catch is this type of science is dependent on the public sector. Basic research into mental illness is notoriously underfunded as it is. For lack of will, then, we may be unable to see our way to the future, much less realize it. The Apollo program was supposed to signal the beginning of manned space exploration. We haven’t been back to the moon since 1972, nor do we have the rockets for it.

The future - so near, yet so far ...

1 comment:

Anonymous said...

I kind of want to comment on this... a huge part of why we are not progressing in mental health treatment is because our current system makes so much money for Pharma, which funds almost all the research, and has no interest in really finding out the roots of people's problems. All "mental disorders" are really syndromes (collections of symptoms) and for all we know, could have different causes or disease pathways, in one person to the next. We will never know, because our current approach, funded by Pharma, is "take meds and hopefully you feel better"- which works for some people and not for others. -Anonymous because I'm too lazy to sign in