Sometimes, rather than time per se, we bind ourselves based on milestones
or accomplishments. We’ll wait till our birthday, or as soon as we complete
an
assignment, or after we get our degree, or once we get the promotion.
When the clock has run down, or we’ve crossed a self-designated finish line,
the drug is our reward.
Neuroscientists S. H. Ahmed and George Koob have shown that rats given
unlimited access to cocaine for six hours per day gradually increase their
lever-pressing over time to the point of physical exhaustion and even death.
Increased self-administration under extended access conditions (six hours)
has also been observed with methamphetamine, nicotine, heroin, and alcohol.
However, rats who have access to cocaine for only one hour per day use
steady amounts of cocaine over many consecutive days. That is, they don’t
press the lever for more drug per unit time with each consecutive day.
This study suggests that by restricting
drug consumption to a narrow
window of time, we may be able to moderate our use and avoid the
compulsive and escalating consumption that comes with unlimited access.
—
Just tracking how much time we spend consuming, for example, by clocking
our smartphone use, is one way to become aware of and thereby mitigate
consumption. When we make conscious use of objective facts like how much
time we’re using,
we are less able to deny them, and therefore in a better
position to take action.
However, this can get very tricky very fast. Time has a funny way of getting
away from us when we’re chasing dopamine.
One patient told me that when he was using methamphetamine, he
convinced himself that time didn’t count. He felt as though he could stitch it
back together later without anyone realizing a piece had gone missing. I
imagined him floating in the night sky, big as a constellation, sewing together
a rent in the universe.
High-dopamine goods mess with our ability to delay gratification, a
phenomenon called
delay discounting.
Delay discounting refers to the fact that the value of a reward goes down
the longer we have to wait for it. Most of us would rather get twenty dollars
today than a year from now. Our tendency to overvalue short-term rewards
over longer-term ones can be influenced by many factors. One of those
factors is consumption of addictive drugs and behaviors.
Behavioral economist Anne Line Bretteville-Jensen
and her colleagues
investigated the discounting in active heroin and amphetamine users
compared with ex-users and with matched controls (individuals matched for
gender, age, education level, etc.). The investigators asked the participants to
imagine they had a winning lottery ticket worth 100,000 Norwegian kroner
(NOK), approximately 14,600 US dollars.
They then asked participants if they would rather have less money right
now (less than 100,000 NOK) or the full amount a week from now. Of active
drug users, 20 percent said they wanted the money right now and would be
willing to take less to get it. Only 4 percent of former users and 2 percent of
matched controls would have accepted that loss.
Cigarette smokers are more likely than
matched controls to discount
monetary rewards (that is, they value them less if they have to wait longer for
them). The more they smoke, and the more nicotine they consume, the more
they discount future rewards. These findings hold true for both hypothetical
money and real money.
Addictions researcher Warren K. Bickel and his colleagues asked people
addicted to opioids and healthy controls to complete a story that started with
the line: “After awakening, Bill began to think about his future. In general, he
expected to . . .”
Opioid-addicted study participants referred to a future that was on average
nine days long. Healthy controls referred to a future that was on average 4.7
years long. This striking difference illustrates how “temporal horizons”
shrink when we’re under the sway of an addictive drug.
Conversely, when I ask my patients what was the deciding moment for them
to try to get into recovery, they’ll say something that expresses a long view of
time. As one patient told me who’d been snorting heroin for the past year, “I
suddenly realized I’d been using heroin for a year, and I thought to myself, if I
don’t stop now, I may be doing this for the rest of my life.”
Reflecting on the trajectory of his whole life,
rather than just the present
moment, allowed this young man to take a more accurate inventory of his
day-to-day behaviors. The same was true of Delilah, who was willing to
abstain from cannabis for four weeks only after imagining herself still
smoking ten years hence.
In today’s
dopamine-rich ecosystem, we’ve all become primed for
immediate gratification. We want to buy something, and the next day it shows
up on our doorstep. We want to know something, and the next second the
answer appears on our screen. Are we losing
the knack of puzzling things
out, or being frustrated while we search for the answer, or having to wait for
the things we want?
The neuroscientist Samuel McClure and his colleagues examined what
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