The Molecule of More

participants’ brains, they found yet another effect: the more active the 
dopamine cells were, the more money the volunteers expected to win.
It’s not uncommon for people to deceive themselves in this way. 
There are few things we encounter in daily life that are more unlikely 
than winning the lottery. A person is more likely to have identical qua-
druplets, or be killed by a vending machine tipping over. It’s over a 
hundred times more likely that a person will be struck by lightning than 
win the lottery. Yet millions of people buy tickets. “Someone has to 
win,” they say. A more sophisticated dopamine enthusiast expressed his 
devotion to the lottery in this way: “It’s hope for a dollar.”
Expecting to win the lottery may be irrational, but far more severe 
distortions of judgment can occur when people take dopamine-boosting 
medicines every day:

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49
DRUGS
On March 10, 2012, lawyers for Ian,
2
a sixty-six-year-old 
resident of Melbourne, Australia, filed a statement of claim 
in federal court. He was suing the drug manufacturer Pfizer, 
claiming that their Parkinson’s medication, Cabaser, made 
him lose everything he had. 
He was diagnosed with Parkinson’s disease in 2003. 
His doctor prescribed Cabaser, and in 2004 Ian’s dose 
was doubled. That’s when the problems began. He started 
gambling heavily on video poker machines. He was retired, 
and received a modest pension of about $850 per month. 
Each month he fed the entire sum into the machines, but it 
wasn’t enough. To pay for his compulsion, he sold his car 
for $829, pawned much of what he owned for $6,135, and 
borrowed $3,500 from friends and family. Next, he took out 
loans for over $50,000 from four financial institutions, and on 
July 7, 2006, he sold his home.
In all, this man of modest means gambled away over 
$100,000. He was finally able to stop in 2010, when he read 
an article about the link between Parkinson’s medication and 
gambling. He stopped taking Cabaser, and the problem went 
away.
Why do some people who take Parkinson’s medication engage in 
destructive behavior, but most do not? It’s possible they were born with 
a genetic vulnerability. People who gambled frequently in the past are 
more likely than others to experience out-of-control gambling after 
they start Parkinson’s medication, suggesting there are certain person-
ality features that put people at risk. 
Another risk of Parkinson’s medication is hypersexuality. A Mayo 
Clinic case series—the tracking of patients with a certain type of illness 
or treatment—described a fifty-seven-year-old man treated with L-dopa 
who “would have sexual intercourse twice daily and, when possible, even 
2 To protect privacy, we have disguised or created composites of individuals and 
their cases throughout the book.

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50
THE MOLECULE OF MORE
more often. Both he and his wife worked full time, and because of her 
busy schedule, she found it difficult to satisfy him.” After he retired at age 
sixty-two, things became worse. He made sexual advances to two young 
ladies in his extended family as well as to women in the neighborhood. 
Eventually, his wife had to leave her job to attend to his sexual urges.
3
Yet another patient expressed his hypersexuality by spending hours 
every day in internet adult chat rooms—but even otherwise healthy 
people taking no medication at all are susceptible to the dopamine call 
of pornography, supercharged by the internet.
Of course, you don’t need Parkinson’s medication coursing through 
your brain to have your life upended by sexual obsession. Consider the 
fearsome triad of dopamine, technology, and porn.
MORE, MORE, MORE: DOPAMINE AND 
THE POWER OF PORNOGRAPHY
Noah was a twenty-eight-year-old man who sought help because he was 
unable to stop viewing pornography. He grew up in a Catholic household, 
and the first time he was exposed to pornography was at the age of fifteen. 
He was on the internet searching for something unrelated when he ran across 
a picture of a naked woman. He said from that moment he was hooked.
At first, things weren’t too bad. He was accessing the internet over a 
dial-up modem and “it took ages for the pictures to load.” He was lucky. 
Technology was limiting his daily dose. He described the pictures he started 
with as “tame.” Over time, both of these would change. Broadband allowed 
him to access pictures instantly, and he could now add video to his daily 
routine. Tame material gave way to depictions of more extreme acts as his 
tolerance for pornographic thrills increased.
He considered his behavior to be a sin, a moral failing, and he used his 
relationship with the church to get his compulsion under control. He went 
3 This problem primarily affects men, but women are not immune. In the Mayo Clinic 
series of thirteen patients, two were female, both single and sexually abstinent 
prior to starting treatment.

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51
DRUGS
to confession on a regular basis, and received emotional support that helped 
him cut back his viewing habits. But when his work assigned him to an 
overseas branch, everything fell apart. Unable to speak the local language, 
he became socially isolated, and his compulsion flared up worse than ever. 
He said, “What makes this so hard is the inner struggle, the conflict within. 
It’s a war against yourself.” Feeling completely out of control, he no longer 
believed it was a strictly moral failing. “I need to fight this on a chemical 
level because at some point I want to get married.”
Thanks to the internet, sexually graphic material is more easily available 
than ever before. Some people maintain that it is possible to become 
addicted to pornography, even for otherwise healthy people taking no 
medication at all. In 2015 the Daily Mail claimed that as many as one 
in twenty-five young adults in the United Kingdom were believed to be 
sex addicts.
A reporter from the newspaper spoke to researchers at the Uni-
versity of Cambridge who described experiments in which they had 
placed young men in brain scanners, and then piped in pornographic 
videos for them to watch. As expected, their dopamine circuits lit up. 
The circuits went back to normal when ordinary videos were displayed.
The scientists put other volunteers in front of a computer, and 
found that of all the content on the internet, pictures of undressed 
women were most likely to make young men click compulsively. They 
also discovered that showing people “highly arousing sexual pictures” 
was distracting when they were trying to pay attention to something 
else. (Amateur scientists can try this experiment at home.) At the end of
the study they concluded that compulsive sexual behavior was fueled by 
easy access to sexual images on the internet.
THE POWER OF EASY ACCESS
When it comes to addiction, easy access matters. More people get 
addicted to cigarettes and alcohol than to heroin, even though heroin 
hits the brain in a way that is more likely to trigger addiction. Cigarettes 

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THE MOLECULE OF MORE
and alcohol are a larger public health problem because they are so easy 
to obtain. In fact, the most effective way to reduce the problems caused 
by these substances is to make it more difficult to get them.
We’ve all seen “quit smoking” advertisements on buses and sub-
ways. They don’t work. We’ve heard about school programs that teach 
kids to say no to drugs and alcohol. In many cases drug and alcohol use 
go up after these programs because they pique the curiosity of the ado-
lescent students. The only thing that has been shown to work consis-
tently is raising taxes on these products and placing limits on where and 
when they can be sold. When these measures are taken, use goes down.
4
As barriers to the use of tobacco have gone up, barriers to pornog-
raphy have gone down. In the past, getting sexually explicit pictures 
was something of an ordeal. People had to muster the courage to walk 
into a drugstore, pick up a magazine, and then hope the cashier wasn’t 
a member of the opposite sex. Today, pornographic pictures and videos 
can be had in seconds and in complete privacy. There are no barriers 
of embarrassment or shame.
We don’t yet know if compulsive viewing of pornography is 
exactly the same as drug addiction, but they have things in common. 
As with drug addiction, people who become trapped in a cycle of
excessive pornography use spend more and more time pursuing this 
activity—sometimes many hours every day. They abandon other activ-
ities so they can focus on adult internet sites. Sexual relations with their