Four rounds of chemotherapy has taken a substantial physical toll on my body. Abdominal cramping begins just a couple hours after the infusion is complete and persists until Thursday of that week. My muscles feel substantially weaker — even when I’ve recovered enough to go on my ritual Saturday three mile jog, I’m moving in slow motion by the last half mile. These are just some of the real quantifiable physical effects of chemotherapy.

Yet, to only acknowledge the physical impact of going through chemo is to only tell half of the story. Being repeatedly poisoned to treat a potentially life threatening condition takes an emotional and psychological toll that can prove just as formidable as all the physiologic side effects.

The increased incidence of depression and anxiety in cancer patients is well-documented. Most studies suggest approximately 20–25% of cancer patients will meet diagnostic criteria for depression at some point in their illness. This makes sense. Chemotherapy saps your energy and makes you feel awful. Even without the mental weight of being diagnosed with cancer, your body is sending your brain plenty of negative sensory input. How can you blame the brain for concluding life is awful?

Fortunately, I have been fortunate to avoid depression in my own cancer treatment saga. To be clear this doesn’t make me “tougher” than those who do suffer from major depression during therapy. If I had to guess I’d say the reason I haven’t gotten depressed breaks down like this:

50% my support structure — I am incredible lucky to have amazing support from family, friends and coworkers. One (or both) of my parents have been able to be in town from Monday to Wednesday for each of my treatment weeks. My girlfriend has been just as supportive and helpful once they’ve left. I’ve received so many texts, cards, and calls from friends and family that I can’t keep track any more. And my residency program has been incredible in making sure that I don’t also have to feel stressed about work.

— I am incredible lucky to have amazing support from family, friends and coworkers. One (or both) of my parents have been able to be in town from Monday to Wednesday for each of my treatment weeks. My girlfriend has been just as supportive and helpful once they’ve left. I’ve received so many texts, cards, and calls from friends and family that I can’t keep track any more. And my residency program has been incredible in making sure that I don’t also have to feel stressed about work. 25% my attitude — This is partly contingent on the excellent prognosis of my particular cancer and the fact that I’m otherwise young and in shape. But I do think its helped that I’ve kept working as much as possible through treatment. Likewise, exercising through chemotherapy has been incredibly therapeutic. If I had instead spent two months at home on the couch, I think the odds of getting depressed would be much higher.

— This is partly contingent on the excellent prognosis of my particular cancer and the fact that I’m otherwise young and in shape. But I do think its helped that I’ve kept working as much as possible through treatment. Likewise, exercising through chemotherapy has been incredibly therapeutic. If I had instead spent two months at home on the couch, I think the odds of getting depressed would be much higher. 25% luck — I believe that genetic predisposition plays a role in depression. I happened to luck out in not being particularly predisposed.

However, while I have fortunately avoided depression (and hopefully will continue to do so), I have not sailed completely smoothly though treatment.

Subconscious anxiety has thrown off my sleep cycle. For most of my life, I’ve slept soundly through the night. During chemo waking up 2–3 times has become the norm and I can’t always fall back asleep. The sources of the anxiety aren’t difficult to pinpoint. I’ve worried about the slim possibility that I’d need more chemotherapy. I’ve worried about developing a fever, given the suppressed state of my immune system — a concern that was amplified leading up to the wedding of my best friend from high school last weekend.

Yet, despite being able to identify my anxieties, I don’t feel particularly anxious during the day. This is mostly great, but makes my restless sleep even more frustrating. I know that the answer is probably subconscious anxiety bubbling to the surface in a less alert state. But it’s still frustrating as hell.

Ultimately, whether my annoying but mostly innocuous sleep disturbances or the more devastating major depression that afflicts others with cancer, the psychological impact of cancer is real.

As humans we’ve evolved a rather unique ability to not only be aware of our existence, but to question its meaning and to pause and reflect upon that which we experience. Yet, even the most powerful supercomputer can be overloaded and short circuit.

Being diagnosed with cancer and subsequently being physically drained by repetitive poisonings is not within the natural realm of human experience. Humans have not evolved adaptive responses to innately withstand chemotherapy. We do our best to make use of our resources (family, friends, exercise, etc) to endure these stresses, but no one goes through the process unscathed.