Addiction in Science Fiction
Jonathan asks for a three-question definition of addiction. Most of my books show addictions of one sort or another; the “stonesickness” in A Door into Ocean, the gambling addiction in The Highest Frontier. Addiction is the core of Brain Plague, where the the most addictive thing in the universe is intelligent microbes. “Micros” live in the brain and communicate by colors. For micros, the human brain looks a lot like the brainbow slice above. The brainbow is a genetically engineered mouse that makes distinct fluorescent proteins in different brain neurons, coloring them hundreds of different colors. Why would we do this, Dr. Frankenstein? Of course–to study medical brain disorders, such as addiction.
Few subjects are the source of greater hypocrisy in our society than addiction. Years ago, we used to distinguish addiction from habituation, which was supposedly non-medical and therefore more OK than addiction. But if you look at this old document I dredged up with its tortuous argument that tobacco smoking is not addictive, you can see that basically society tries to deny that legal socially acceptable substances or practices are addictive. This notion lies behind much of the snarky attitude of Brain Plague. Today the old argument has largely been rejected. Furthermore, we realize that even behaviors not involving pharmaceuticals–such as eating disorders–can interact with the same central brain system or reward pathway.
To get an idea of how drugs interact with the reward pathway, I recommend the interactive demo Mouse Party. While I wish it included nicotine and other legal drugs, the ones it does include are pretty good. Basically, one way or another most addictive drugs or behaviors overload the dopamine pathway that makes pleasure. (Many other neurotransmitters like serotonin are also involved, but dopamine seems to be the most central.) The speed of response, intensity, and duration all contribute to the addiction tendency. Nicotine and cocaine act particularly fast. MDMA (ecstasy) has particularly long-lasting effect.
But the key thing that happens with any stimulus–whether light on your retina, sound on your ear’s hair cells, or something releasing dopamine–is adaptation. Adaptation means that during a stimulus, the body adjusts to lower responsiveness (or increase the threshold for response). So the longer, and the more intense, the stimulus, the sooner you adapt–and feel worse upon removal of the stimulus. That’s why cocaine and nicotine users scrabble around looking for more, as the effect wears off. Prolonged users of a substance may eventually experience permanent adaptation, so they can never recover the ability to “feel good” — with or without the substance. A similar thing happens with dieters–having experienced a higher fat level, one feels permanently starved.
How do you know if you’re “addicted” to something? That’s not easy because the medical profession, and society at large, have no clear definition. In Brain Plague, the characters don’t agree either; and the definition they start with evolves throughout the book. Nevertheless, as a practical matter, I suggest the following three questions:
- Can I stop?
- When I stop, am I a functional person?
- If I don’t stop, am I a functional person?