It’s just a thought (feeling?)…
A couple of sayings are bouncing around in my head right now:
Use it or lose it.
It’s all in your head.
I recently read in a New Yorker article by Joshua Rothman that the brain is the only organ that has two medical specialties - neurology and psychiatry. I have always been intrigued by this idea that the organic mass of the brain can be so disassociated in our minds from the thoughts, feelings, and personalities it generates. The brain, with intricate neural pathways that generate motor signals to move muscles, perceive sensory signals to alert of us pain, is also a source of mood, personality, and memories. How can we draw a line between the neural circuitry and processes that produce visible/examinable/measurable outputs and those that are only felt or thought?
My aim for understanding this dichotomy is to consider wether the diseases assigned to neurologists (stroke, headache, dementia) are really as easily demarcated from the diseases assigned to psychiatrists (depression, anxiety, mania). When I was in medical school and residency, my grandfather was manifesting later stages of Alzheimers disease. He would ask the same questions, forget he had already eaten ice cream and attempt to get more, and even once tried to relight the pilot light of the stove by catching a paper towel on fire with the toaster. The last one was purely a Baba Kazem style ingenuity. Despite loss of many of his faculties, he had always been a McGyver type. My cousin asked me once if Baba Kazem’s Alzheimer’s could have manifested from years of trying to forget bad memories in his life (a very difficult start to life, most of which us grandchildren probably didn’t know about and loss of an adult daughter, to name a few). At the time, I categorically denied his hypothesis. Alzheimer’s is due to accumulation of amyloid beta protein and neurofibrillary tangles - end of story.
As these things go, as you exit the assuredness of young adulthood and come to understand the certainties of this world are few, I started to see the manifestations of Primary Progressive Aphasia (PPA) in my mother and rethink my response to my cousin’s question. The subtype of disease she has, logopenic variant, is pathologically similar to Alzheimers disease with amyloid deposition and tau build up. Difficulty processing language and errors in speech production are the initial manifestations of disease. My mother and I always had difficulty communicating, talking past each other. Were those early disagreements, my sense that she rarely directly answered my questions or understood my meaning, an early manifestation of the disease? Or was it that her lack of attention and practice of communication skills laid her language circuitry vulnerable to disease? She had instead honed a voracious appetite for collecting things (likely a product of scarcity in her childhood) and now manifested a strong attachment to her purses, silverware and often went out shopping for the same things everyday - milk, muffins, and toothpaste accumulating in her apartment with no rhyme or reason. Maybe the “use it or lose it” idea applied to her thoughts?
A pitfall of this way of thinking would be to blame people for their disease. My experiences in life have aligned more with the Robert Sapolskly line of causation - factors so remote from our current will set in motion our predispositions and formed our primordial soup that I cannot fathom a way of blaming anyone for their freckles, least of all their thoughts and disease. Similarly, as Sapolsky explains (and I attempt to capture in a nutshell here), many of the genes that influence behavior are unlikely to predetermine all of our fate. They likely predispose us to certain behaviors, when coupled with the “appropriate” experiences and environment. In plainer terms, so much of what defines us is formed before we even form memories by people (parents, guardians) that were formed before they even formed memories, so forth and so on to the beginning of time.
So how would this come together at a molecular level? My imagination can stretch to the possibility that neural activity (a particular thought or feeling) in the brain may promote protein synthesis and clearance in some circuits or patterns, more so than in others, and depending on the disease and pathological mechanisms, this may promote the phenotype and manifestations of that disease in an individual. Bringing together nature and nurture, another separation I have always found unsettling.
To think our feelings and thoughts can influence disease manifestations at a molecular level gives a whole new meaning to “It’s all in your head.” It’s usually mentioned casually to dismiss someone’s interpretation of an event or experience of a symptom. But isn’t so much of life in our heads? At this point, their is no dispute that certain diseases are co-morbid with depression or anxiety. For example, recognition of memory difficulties in cognitive impairment is often manifested with depression. Our understanding of migraine has flipped - with the thought that sleep disruption, change in appetite triggering a migraine now being challenged as these manifestation being a prodrome of migraine.
What does this have to do with a preventive neurology mindset? For me, it is an important reminder that not all measures of health are quantifiable or imageable. In some ways, we are what we think. Being deliberate about understanding our thoughts and feelings likely has far reaching implications for our cognitive health.