Monday, November 30, 2009
As it turned out, I couldn’t get anterior cingulate cortex (ACC) out of my head. It’s as if my own ACC couldn’t filter out my own speculative obsessions about this individual’s ACC. Screw this psychiatry bullshit, I wanted to scream. Open up the hood, poke around inside, find out what’s wrong, and fix the goddamn thing.
So here I am, late Thanksgiving evening, burping up my afternoon prandial over-indulgences, when I come across a New York Times front page story on psychiatric brain surgery. I’ve previously written stories on this. Guess which part of the brain we’re talking about?
Now my ACC is lighting up like a Christmas tree.
I wake up the next morning only to discover that my fellow blogger Willa Goodfellow has just published a piece on Prozac Monologues, entitled: Thanksgiving and the Anterior Cingulate Cortex.
That’s not the end of the story. Last August, I cited Willa as one of my top six bloggers. In my review, I said: “Let's put it this way: Until I encountered Prozac Monologues, I thought I was the only one who had ever mentioned, anterior cingulate, in a blog.”
Now my ACC is in Captain Ahab Moby Dick mode:
All that most maddens and torments; all that stirs up the lees of things; all truth with malice in it; all that cracks the sinews and cakes the brain; all the subtle demonisms of life and thought ...
Okay, some basics:
The ACC is part of the cingulate cortex, which snakes beneath the brain’s outer cortices. The region has more specialized functions across different areas than a world religion has schisms and heresies and sects, but the simple version is that the ACC plays a major role in modulating the two-way traffic between the brain’s limbic and cortical regions. It is also wired into other circuits known as "cortico-striatal-thalamic-cortical loops," which has to do with filtering out irrelevant thoughts and emotions and sensory inputs, thus allowing us to focus on the relevant ones.
Significantly, anterior cingulate malfunction has been implicated in all manner of mental illnesses, from depression and bipolar to ADD to OCD to schizophrenia. On a most elemental level, when the brain is unable to filter out the overload, the “I” that is supposed to be in charge is overwhelmed and can’t cope. For instance, in OCD the brain literally locks onto one thought and can’t let it go.
So here was the person close to me, obsessed on fearful end-of-the-world thoughts, depressively ruminating to the point of psychosis or near psychosis, and totally lacking the ability to make a rational assessment of his present and plan his future. It had to be the ACC.
Ha! If only life were so simple. In a review article in “Psychiatry,” Dhwani Shah MD of the University of Pennsylvania et al point out that “psychiatric syndromes cannot be localized in a single, so-called ‘abnormal’ brain region.” Rather, “mood and anxiety disorders involve immensely complex interconnected systems or networks of organization within the brain.”
Take my depression - please! The authors are quick to point out that the causes of depression are complex and only partly understood. Nevertheless, a picture is beginning to emerge of interconnecting brain systems in a state of stress-induced collapse. The technical term is allostatic overload, which is what happens when a highly complex and self-regulating system such as the brain fails to maintain homeostasis (equilibrium).
As Shah et al describe it, the brain circuitry involved in depression is grouped into three main components: cortical (appearing to give rise to the psychomotor and cognitive aspects of depression), subcortical (involving the affective aspect of depression, including anhedonia and sadness), and modulatory (regulating two-way cortical-limbic traffic, including stress and hormonal pathways).
Okay, here’s where it gets interesting. Brain systems may be infinitely and infernally complex, but we are beginning to see the merit in zeroing in on specific strategic targets (or “nodes”) in experimental surgical interventions. Significantly, for OCD and depression, that target is the ACC (more specifically for depression, the subgenual anterior cingulate corresponding to Brodmann area 25).
Lest we create a false impression, psychosurgery is almost certainly not the future of psychiatry. But it is simply impossible to imagine a different tomorrow without coming to grips with how a surgical technique of last resort is changing how we look at mental illness.
Trust me, things are changing.
To be continued ...