What causes opioid addiction, and why is it so tough to combat? - Mike Davis
More than 3,000 years ago,
a flower began to appear in remedies
in Ancient Egyptian medical texts.
Across the Mediterranean,
the ancient Minoans
likely found ways to use
the same plant for its high.
Both ancient civilizations
were on to something—
opium,
an extract of the poppy in question,
can both induce pleasure
and reduce pain.
Though opium has remained
in use ever since,
it wasn’t until the 19th century
that one of its chemical compounds,
morphine, was identified
and isolated for medical use.
Morphine, codeine, and other substances
made directly from the poppy
are called opiates.
In the 20th century, drug companies
created a slew of synthetic substances
similar to these opiates,
including heroin, hydrocodone,
oxycodone, and fentanyl.
Whether synthetic or derived from opium,
these compounds
are collectively known as opioids.
Synthetic or natural, legal or illicit,
opioid drugs
are very effective painkillers,
but they are also highly addictive.
In the 1980s and 90s,
pharmaceutical companies began
to market opioid painkillers aggressively,
actively downplaying
their addictive potential
to both the medical community
and the public.
The number of opioid painkillers
prescriptions skyrocketed,
and so did cases of opioid addiction,
beginning a crisis that continues today.
To understand why opioids
are so addictive,
it helps to trace how these drugs affect
the human body from the first dose,
through repeated use,
to what happens when long-term use stops.
Each of these drugs
has slightly different chemistry,
but all act on the body’s opioid system by
binding to opioid receptors in the brain.
The body’s endorphins temper pain signals
by binding to these receptors,
and opioid drugs bind
much more strongly, for longer.
So opioid drugs can manage much more
severe pain than endorphins can.
Opioid receptors also influence everything
from mood to normal bodily functions.
With these functions, too,
opioids’ binding strength and durability
mean their effects
are more pronounced and widespread
than those of the body’s
natural signaling molecules.
When a drug binds to opioid receptors,
it triggers the release of dopamine,
which is linked to feelings of pleasure
and may be responsible
for the sense of euphoria
that characterizes an opioid high.
At the same time, opioids suppress
the release of noradrenaline,
which influences wakefulness, breathing,
digestion, and blood pressure.
A therapeutic dose decreases noradrenaline
enough to cause side effects
like constipation.
At higher doses opioids can decrease heart
and breathing rates to dangerous levels,
causing loss of consciousness
and even death.
Over time, the body starts
to develop a tolerance for opioids.
It may decrease its number
of opioid receptors,
or the receptors may become
less responsive.
To experience the same release of dopamine
and resulting mood effects as before,
people have to take
larger and larger doses—
a cycle that leads to physical dependence
and addiction.
As people take more opioids
to compensate for tolerance,
noradrenaline levels
become lower and lower,
to a point that could impact
basic bodily functions.
The body compensates by increasing
its number of noradrenaline receptors
so it can detect much smaller amounts
of noradrenaline.
This increased sensitivity
to noradrenaline
allows the body
to continue functioning normally—
in fact, it becomes dependent on opioids
to maintain the new balance.
When someone who is physically dependent
on opioids stops taking them abruptly,
that balance is disrupted.
Noradrenaline levels can increase
within a day of ceasing opioid use.
But the body takes much longer
to get rid of
all the extra noradrenaline receptors
it made.
That means there’s a period of time
when the body is too sensitive
to noradrenaline.
This oversensitivity causes
withdrawal symptoms,
including muscle aches, stomach pains,
fever, and vomiting.
Though temporary, opioid withdrawal
can be incredibly debilitating.
In serious cases, someone in withdrawal
can be violently ill
for days or even weeks.
People who are addicted to opioids
aren't necessarily using the drugs
to get high anymore,
but rather to avoid being sick.
Many risk losing wages or even jobs
while in withdrawal,
or may not have anyone to take care
of them during withdrawal.
If someone goes back
to using opioids later,
they can be at particularly high risk
for overdose,
because what would have been a standard
dose while their tolerance was high,
can now be lethal.
Since 1980, accidental deaths
from opioid overdose
have grown exponentially
in the United States,
and opioid addictions have
also exploded around the world.
While opioid painkiller prescriptions
are becoming more closely regulated,
cases of overdose and addiction
are still increasing,
especially among younger people.
Many of the early cases of addiction
were middle-aged people
who became addicted to painkillers
they had been prescribed,
or received from friends
and family members with prescriptions.
Today, young people are often introduced
to prescription opioid drugs in those ways
but move on to heroin or illicit
synthetic opioids that are cheaper
and easier to come by.
Beyond tighter regulation
of opioid painkillers,
what can we do to reverse the growing
rates of addiction and overdose?
A drug called naloxone is currently
our best defense against overdose.
Naloxone binds to opioid receptors
but doesn’t activate them.
It blocks other opioids
from binding to the receptors,
and even knocks them off the receptors
to reverse an overdose.
Opioid addiction
is rarely a stand-alone illness;
frequently, people with opioid dependence
are also struggling
with a mental health condition.
There are both inpatient
and outpatient programs that combine
medication, health services,
and psychotherapy.
But many of these programs
are very expensive,
and the more affordable options
can have long waiting lists.
They also often require complete
detoxification from opioids
before beginning treatment.
Both the withdrawal period and the common
months-long stay in a facility
can be impossible for people who risk
losing jobs and housing in that timeframe.
Opioid maintenance programs aim
to address some of these obstacles
and eliminate opioid abuse
using a combination
of medication and behavior therapy.
These programs avoid withdrawal symptoms
with drugs
that bind to opioid receptors
but don’t have the psychoactive effects
of painkillers, heroin,
and other commonly abused opioids.
Methadone and buprenorphine
are the primary opioid maintenance
drugs available today,
but doctors need a special waiver
to prescribe them—
even though no specific training
or certification
is required to prescribe
opioid painkillers.
Buprenorphine can be so scarce
that there’s even
a growing black market for it.
There’s still a long way to go
with combating opioid addiction,
but there are great resources
for making sense of the treatment options.
If you or someone you know is struggling
with opioid use in the United States,
the Department of Health
and Human Services
operates a helpline: 800-662-4357
and a database of more than 14,000
substance abuse facilities in the US:
www.hhs.gov/opioids
