PWS Visser 2018-2019

WHAT IS THE EFFECT

OF THE ADDICTION

GENE ON A SMOKING

ADDICTION?

2018-2019

J o y c e S t r a v e r

E v a N i e u w e n h u i j s

smoking addiction Page 01

CONTENTS

1 . W h a t i s a s m o k i n g a d d i c t i o n ?

1 . 1 W h a t i s a n a d d i c t i o n ?

1 . 2 e f f e c t s o n a s m o k i n g a d d i c t i o n

2 . W h i c h f a c t o r s p l a y a r o l e i n a s m o k i n g a d d i c t i o n ?

2 . 1 s o c i a l f a c t o r s

2 . 2 a v a i l a b i l i t y f a c t o r s

2 . 3 b e h a v i o r a l f a c t o r s

2 . 4 p e r s o n a l f a c t o r s

3 . H o w d o e s t h e a d d i c t i o n g e n e h a v e i n f l u e n c e o n

a s m o k i n g a d d i c t i o n ?

3 . 1 w h a t i s t h e a d d i c t i o n g e n e ?

3 . 2 i n t e r v i e w a d d i c t i o n w i t h p r o f . d r . V e r w e i j

4 , C o n c l u s i o n

5 . D i s c u s s i o n

6 . S o u r c e s


1. WHAT IS A SMOKING ADDICTION?

1.1 WHAT IS ADDICTION?

An addiction is a state in which a person

is mentally or physically dependent on

something. This can be a habit, an

action, a feeling or a substance. This

usually goes at the expense of other

activities, since you cannot stop this

addiction easily. We can divide

addictions into two groups: a habit

addiction or a substance addiction. A

habit addiction is when a person does a

specific activity that gives them a kick

and makes them feel good. Examples of

these habits are: gaming, sex, gambling

and shopping. A substance addiction is

when a person is addicted to one or

more substances. People who have a

substance addiction are not addicted to

the kick, but the substance has a direct

influence on the brain, that is why these

substances are also called psychoactive

substances. Psychoactive substances

can also be divided in three groups:

- Stimulating substances: cocaine,

nicotine

- Numbing substances: alcohol, opium

- Psychedelic substances: XTC, LSA

The most common addictions are nicotine

and alcohol. In the Netherlands,

600.000 people have a tobacco

addiction and 480.000 people have an

alcohol addiction This indicates that a

smoking addiction is a big problem in the

Netherlands.

25% of the Dutch population above the

age of 15 smokes, whereof most are

addicted as well. The habit of smoking

and the nicotine are the cause of the

addiction. The nicotine in the tobacco

works as a mental and physical

addiction. Nicotine stimulates the

production of dopamine which causes a

moment of joy and delight. This shows

that there is a relation between

dopamine and the reward center in the

brain. When someone experiences a

moment of joy the brain produces

dopamine, this happens

O when brain wants you eat, another

drink, moment have sex, of exercise, joy

and the do person drugs and will when

repeat you the smoke. same action.

After this, Thethe

brain will produce dopamine again and

this can cause an addiction. (The brain

links fun situations with lighting a

cigarette. That's why you also see many

people smoking at a party.)



Exercising also produces dopamine in

the body. Which happens with a smoking

addiction as well. Dopamine keeps you

motivated to keep going, gives a sense

of reward and makes you happy. Not

only does the brain produce dopamine

when you sport but it also produces

endorphin and serotonin; all

neurotransmitters. A neurotransmitter or

transfer agent is a signal substance that

transmits nerve impulses in synapses

between nerve cells ('neurons') in the

nervous system or transmits impulses

from motor nerve cells to muscle cells or

nerve receptors on sensory nerve cells.4

Endorphin gives you a euphoric feeling

and reduces pain. That is why it is

called the 'feel good' drug. Serotonin,

also called the happiness hormone,

gives you a blissful feeling and

regulates your appetite, mood and

sleep.

Besides the fact that you can get

addicted to cigarettes, there are a lot

of other processes that will occur in the

brain, which will have a negative effect

on the smoker.

The brain will not process important

information anymore, which can be very

harmful. This was one of the results of a

research done by American Harvard.

They observed 31 chain-smokers (more

than 15 cigarettes a day) and 31

nonsmokers by letting them gamble with

100 dollars, while they were lying in a

brain scan. This showed that smokers

ignore important information. The

smokers seem to be focusing on the

actual profit and loss, but not on what

their profit or loss would be if they

made another decision. From their point

of view that is not important. On the

contrary, the nonsmokers were focusing

on the profit or loss they would get if

they made another decision. The

nonsmokers left with more money than

the smokers.

Lung cancer, a heart attack and

impotence; smokers know the

consequences of smoking, but why do

they keep smoking? This is the same

problem as with the 100dollar

experiment; they ignore the important

information. This is really confusing for

the smoker, because they process the

information, they know the

consequences and know O the

importance of those. But before they

light their next cigarette, their

subconscious state loses the information

somewhere in the brain. So, before they

even think about it, they smoke another

cigarette. They feel like this cigarette is

even better than the previous one,

which of course is not true, because the

brain does not produce more dopamine.



Smokers indeed seem to overestimate

the pleasure of smoking. Many smokers

acknowledge that life with cigarettes

might be riskier, but more fun. Research

indicates that this is not true. Even so,

smoking makes you unhappier. The

average level of happiness in the

'smokers' group was well below that of

the 'non-smokers' and 'exsmokers'

groups. On top of that; according to

Spanish and American researchers,

smoking and depression seem to relate

to each other. They observed 8000

Spanish smokers and 9000 Finnish

smokers for over a period of 6 years

and compared them to non-smokers.

They found out that smokers have a

bigger change of becoming depressed

than nonsmokers, a 40% chance as

opposed to the non-smokers.

Also, the Harvard researchers are

convinced that the o peculiar

characteristics of smokers' brains are at

least partly caused by smoking. Another

part may well be a matter of aptitude:

characteristics that we have from birth

that makes it easier for people to start

with smoking.

It seems like the substances of a

cigarette changes the brain. And so, the

smoker will overestimate the importance

of smoking. The Harvard study explains

why most advice and campaigns do not

work. The warnings on cigarette boxes

(smoking kills) will probably only ensure

that smokers will become extra

convinced that smoking is nice. They do

not associate smoking with sickness and

death, but with pleasure, because they

would rather live a riskier life.


1. WHAT IS A SMOKING ADDICTION?

1.2 EFFECTS ON A SMOKING ADDICTION

Everyone knows nowadays that smoking

kills you, it even says so on the

package. You will not notice many

effects at the start of smoking, because

it will begin to show in the course of

time. The most harmful substances in a

cigarette are nicotine, tar and carbon

monoxide.

Tar is a black sticky substance that

sticks on the cilia of the mucous

membrane. As a result, the cilia become

less mobile and more damaged. They

cannot abduct the dirt and dust that

well anymore. As said before, nicotine is

the addictive substance in a cigarette.

It is transported to the brain within 7

seconds, where it affects the process of

releasing adrenaline. This causes a high

heart rate and high blood pressure.

After one and a half hours after

smoking the cigarette, half of the

nicotine disappears within the body and

the smoker will feel uneasy and will

want to smoke another cigarette as soon

as possible. Carbon monoxide is a

colorless and odorless gas that enters

your lungs during smoking. This blocks

the way to get oxygen to the organs.

This will reduce the performance of the

organs. Furthermore, it will damage the

walls of vessels, making it easier to

deposit fat and calcium, which leads to

arteriosclerosis and thereafter to heart

diseases.

Moreover, there are of course many

other risks when you smoke daily.

These can be short term or long term.

Short-term:

- Condition: smoking will cause the

carbon monoxide to block the oxygens

way to the lungs, which will result in

your other organs not getting enough

oxygen and your condition will worsen.

- Odor: The smoke will stay

everywhere. In your clothes, hair, room

and your breath, which is not pleasant

for bystanders.

- Nicotine poisoning: This often occurs

when a person begins smoking. The

smoker will get dizzy, nauseous and

even vomit. When it is a heavy

poisoning, o people sometimes fall into

a coma. This can happen when a small

infant eats a cigarette.

- Second hand smoke: When someone

in your surrounding area smokes, 85% of

the smoke will get into the air and

eventually in your lungs as well. So even

if you do not smoke, there is still a

chance the smoke from your smoker

friends will affect you.


1.2 EFFECTS ON A SMOKING ADDICTION

Long-term:

- Chronic bronchitis: this is a chronic

infection in the mucous membrane which

causes you to cough. This can damage

your alveoli.

- Lung emphysema: this happens when

your alveoli are damaged or completely

gone. It causes shortness of breath,

because your lungs got smaller which

makes it harder to give oxygen to the

rest of your body.

- (lung) cancer: this is caused by

abnormal cell growth in damaged places

in the lungs, which can result in cancer.

- Heart and vascular disease: Nicotine

and carbon monoxide damage your veins

throughout your whole body. Cholesterol

and other cells can build up in a certain

part of one of your veins which can

cause a blockage. This can be very

dangerous, because it can result in a

heart attack.

- Gastrointestinal disorders: when

smoking, you have a greater chance of

getting gastrointestinal disorders.

- Bad skin and teeth: Tobacco causes

the skin and teeth to look old and

unhealthy.

This is because too little oxygen is in

your body.

- Vocal cords: Due to mucus and the

coughing, your vocal cords get

damaged or infected. The clearness of

the voice will be lost.

- Memory: Smoking can have a very

negative influence on your memory.

- Pregnancy: Smoking while pregnant,

is very dangerous for the unborn child.

the fetus will grow slower and will also

get the toxic substances in his or her

blood by the mother. This can have very

bad consequences.

Moreover, there are of course many

other risks when you smoke daily.


2.0 WHICH FACTORS PLAY A ROLE IN A

SMOKING ADDICTION?

Studies have shown that people under

the age of twenty are more likely to

start smoking than people above the

age of twenty. There are more men than

women that smoke regularly. On

average, 3,2% of students between the

age of 12 through 16 smoke daily, thus

have a smoking addiction. Studies have

also shown that foreigners are more

likely to have a smoking addiction than

non-foreigners. For example, 59% of

Turkish men living in the Netherlands

have a smoking addiction, whereas 31%

of Dutch men have a smoking addiction.

There is a bigger chance that teenagers

with divorced parents will start smoking.

People with a higher socioeconomic

status are less likely to start smoking

than people with a lower socioeconomic

status. On average, 6,7% of students

doing vmbo-b smoke daily, whereas

0,8% of students doing \ANO smoke

daily. There are a lot of factors that can

cause a smoking addiction. There are

social factors, availability factors,

personal factors and behavioral factors.

2.1 SOCIAL FACTORS

Under social factors we think of (for

example) the role their parents have; if

the parents smoke and what they think

of smoking. There is a bigger chance

that children with parents that smoke

will also start smoking.

U If the parents think it is normal to

smoke, then their child will probably

think the same. A study (Emory et al.,

2010) researching 19 other studies,

showed that by 16 of the 19 studies,

researchers found a connection between

non-smoking rules of parents and their

adolescent children. This study has

shown that the association between

rules of the parents and their children

came out to be stronger in families

where the parents did not smoke.

Moreover, another study showed that

non-smoking rules have a protective

impact on the transition between

nonsmoking and experimenting with

smoking. Setting up non-smoking rules

when they already are experimenting

with smoking is less effective.

They also found that non-smoking rules

had no effect when the father smoked,

but when the father did not smoke the

rules did have effect. They concluded

that when the behavior of the father did

not match the rules, the rules would not

have any effect on the adolescent.

Not only the parents play a role, their

friends do too. It is very common, peer

pressure. Adolescents fear rejection of

their smoking friends. They believe that

if they do not smoke, they will not be

part of the group. So, they will start

smoking to feel like they belong in the

group.


2.0 WHICH FACTORS PLAY A ROLE IN A

SMOKING ADDICTION?

2.2 AVAILABILITY

Availability factors also play a role in a

smoking addiction. When the price of

cigarettes decrease, people are more

likely to buy them since they are

cheaper. So how much does it cost

(nowadays) to be a smoker daily? On

average, a chain smoker smokes 10

cigarettes a day. One pack of cigarettes

contains 19 cigarettes (Marlboro), which

costs 6 euros. 10 x 7 = 70 cigarettes per

week, which is 3,7 packs a week. This

means 191 ,6 packs a year, which is

equal to 191 ,6 x 6= 1.149,47 euros a

year. So, smoking is not only bad for

you, it also empties your wallet.

2.3 BEHAVIORAL

Research shows that a smoking

addiction is related to behavioral

factors such as driving under the

influence of alcohol, antisocial behavior

(aggression, theft and vandalism),

unsafe sexual behavior and poor school

performance. It is a pattern of

rebellious, recalcitrant and deviant

behavior. When doing one rebellious

act, people are often inclined of

continuing these acts, whereas smoking

is one of them.

2.4 PERSONAL

Personal factors also have influence on

a smoking addiction. When speaking of

personal factors, you can think of the

ability to resist peer pressure when it

comes to smoking. Depression, other

mental illnesses and personality traits

such as thrill- and sensation seeking and

being extrovert are also personal

factors which can lead to a smoking

addiction. Then of course, biologic

factors, which the rest of our paper will

be about. Some people are more

sensitive to addictions than others, due

to a genetic predisposition. We will

focus on this specific factor throughout

the rest of the paper.


3. HOW DOES THE ADDICTION GENE HAVE

INFLUENCE ON A SMOKING ADDICTION?

3.1 WHAT IS THE ADDICTION GENE?

There are many ways that genes could

cause one person to be more vulnerable

to addiction than another. --Dr. Glen

Hanson

The results were that adolescents from

the age of 12 through 14 were only

influenced by their environment, not

their genes, as you can see here.

It is not just one gene that says, 'you

will get an addiction later in your life,'

because genetics do play a role, but not

as big a role as environmental factors.

Addiction vulnerability is a very

complex trait, thus finding addiction

genes is difficult as well. Not every

person who is an addict, will have the

same gene and not everyone who has

the addiction gene will show addiction

symptoms.

The addiction gene is inheritable, so it

often runs in families. On the right, you

can see an example of how the gene can

affect a family tree. The red are

carriers of the gene and the white are

non-carriers of the gene. To study the

addiction gene, researchers compare

the DNA of a large family that shows

symptoms of vulnerability for addiction.

But as adolescents move from initial

experimentation, to more established

regular pattems of use, their genes

become important and the effect of

environmental factors drastically drops,

as you can see down here.

Dr. Danielle Dick researched that some

people are born with a certain sequence

DNA that makes us more at risk

OLearn.Genetics for addictions or

mental illnesses. With the help of other

researches in Finland, she researched

the drinking behavior of young

adolescents ( 12-14 ) until their early

adulthood.


3.2 INTERVIEW WITH PROF. DR. VERWEIJ

We asked prof. Dr. Verweij if she would

be open for an interview with us. She

agreed and we went to AMC in

Amsterdam to ask her certain questions

about addiction and genes. The

questions and their answers are as

followed:

How does an addiction develop?

Starting to use cigarettes, alcohol but

also cannabis is partly genetically

explainable; about 40% is caused by

genes and the other 60% is caused by

your environment. What kind of friends

you have, where you live and what you

experience in life. Especially the step

from habitual use to becoming an addict

depends on your DNA. When you are an

addict, it is already decided for 70% in

your DNA that you would be an addict,

but the other 30% of environmental

factors have to influence the rest of the

addiction. What the drug does to your

brain and how much of the drug you

want to use is already saved in O your

DNA.

How does an addict behave and

what happens in their brain?

In the brain there is a so-called reward

center, which plays an important part in

normal life. If you are hungry, then you

go eat, which results in getting a

'reward' in your brain. This rewarding is

for all kinds of habits or substances like

food, alcohol, cigarettes or sex. To make

sure you enact this behavior, you get

rewarded, which also applies when you

take cannabis or nicotine. So, what

happens to an addict; they use a drug

and feel the reward in their brain, which

goes away after a while and then they

want to get back to that feeling of

reward. How strongly you urge to get

the feeling of reward again, is different

for each person. But the urge is

stronger for an addict than a nonaddict.

Addicts get used to this feeling

and are in the need for more of the drug

every time they use. When the addiction

is bad, they will get withdrawal

symptoms after a day of not using.



What is the addiction gene and is

it heritable?

The addiction gene is heritable, and

you often see in families that when a

brother, sister, father or mother is

addicted, you have a higher chance to

becoming addicted too. The o addiction

gene is not one gene, there are a lot;

hundreds and maybe thousands of little

genes and they all play a little role in an

addiction. For example, by smoking we

found a couple of pieces where we are

sure of that they do something to fortify

the addiction, such as the nicotinereceptor

gene, which is a gene that

plays a role in the adhesion of nicotine.

Everyone has this gene, but we all have

different versions of this gene. With one

version you have a bigger chance to

become an addict and with the other

version you have a minor chance of

becoming an addict. Most people who

are addicted to cigarettes, often have

that specific gene. But, because there

are hundreds of genes that play a role,

it does not mean that when you have

that one specific gene you will become

an addict. The addiction gene is not

something that exists, it is a whole

group of different genes.

Does the addiction gene have

impact on the smoking behavior of

a chain smoker?

Since it is not just one gene that

influences an addiction and it is not just

genes that influence an addiction, it is

very hard to tell. But these genes can

be fortified in combination with

environmental factors. Though, these

genes can influence how addicted

someone gets and how much you smoke.



What percentage of the people

with an addiction gene get an

addiction?

That is hard to say, suppose there are a

thousand genes that play a role, and if

you have all those bad variants of those

genes then the chances are much higher

than when you do not have all those bad

variants. But usually you do not have all

those bad genes, you also do not have

zero of those bad genes; it is always

somewhere in between. In addition, you

have the environmental factors. If you

grow up in a family where no one

smokes and you go to a school where no

one smokes while you have all those bad

variants of those genes, you might have

a bigger risk of becoming addicted

when looking at the heritable side, but

your environment does not trigger those

genes

and you will not get addicted. Mostly it

is a combination of your DNA and your

environment.

You can look at this by twins; they have

the same DNA, often also the same home

situation but a different social

environment, especially their group of

friends. So even though they have the

same DNA, it does not mean they follow

the same path. Their environment also

plays a very big role.

Do adolescents have a bigger

chance to have a drug addiction

when the start smoking at an early

age?

If you start smoking at an early age,

then yes, you have a bigger chance of

getting addicted to another substance.

People who start at an early age will,

from a genetically point of view, be

more sensitive to other addictions. If

you start with something more innocent

like cannabis, you will say yes to hard

drugs more easily than someone who is

not addicted to something like cannabis.



Which substance do people with

the addiction gene most likely get

addicted to?

This is different for everyone, so it is

hard to say. In the Netherlands, it will

most likely be alcohol, since it is socially

acceptable. When it is socially

acceptable, some people might drink

more, which often leads to an alcohol

addiction. A big factor is how easily you

can get your hands on a substance.

Alcohol and cigarettes are legal (above

the age of 18) and thus easily

obtainable. But heroin for example, a

very addictive substance, is very hard

to get your hands on and thus not easily

obtainable. That is why there are less

people addicted to heroin than people

who are addicted to alcohol or

cigarettes.

Do people with for example ADHD

have a bigger chance of

developing an addiction when they

have the addiction gene? If so, do

these genes strengthen each

other?

ADHD influences addictions, because

people with ADHD are often more

impulsive, so they are more likely to use

a substance faster. They often show

risky behavior.

Is the addiction gene difficult to

do research on?

Yes, you need very big groups of people

to research, because the effect is so

small. A new study (which is not

published yet) has about one million test

subjects, who gave their DNA and filled

in a questionnaire. Nowadays,

researches can genotype their whole

DNA. So, researchers can compare

certain parts of the DNA and look at the

different variants. This can show how

the DNA of a smoker can differ from the

DNA from a nonsmoker. Technically, it is

not very difficult, but it is a very big

group to genotype, so it costs a lot of

time.

Does raising the price of

cigarettes help stop the addiction?

Yes, it works. Australia is a good

example; the price of a pack of

cigarettes is 20 euros. Compared to the

Netherlands, that's three times its price.

This high price resulted in less smokers

in Australia. Also, the Netherlands

changed the legal age of smoking from

16 to 18. These measures had an

influence on the smoking behavior of

adolescents and adults. The measures

especially help people who have not

smoked yet before, rather than people

who already smoke.



How do you recover from an

addiction?

Do you think there is an effective

way to prevent an addiction?

You can get medication like nicotine

patches to get rid of your smoking

addiction. But most importantly, you

must change your behavior. The physical

part of getting rid of an addiction, is

easy with the right medication, but it is

the mental part of getting rid of an

addiction which is the hardest. Often,

cognitive behavior therapy is given to

be mentally prepared to quit your

addiction.

Raising the price of cigarettes and

getting rid of smoking areas for

example, is an effective way to make it

harder to smoke and thus preventing

people from having an addiction. If you

make sure people do not start smoking,

then we do not have to convince people

to stop. So, prevent the problem, rather

than solving it.


4. CONCLUSION

So, what is the effect of the addiction

gene on a smoking addiction? The

answer is not that simple. That is

because the addiction gene does not

really exist in a singular definition.

There is not one bad gene that causes

an addiction, there are thousands of

genes that play a little role when it

comes to becoming more sensitive to

developing an addiction. Because they

play such a tiny role, they all have little

effect on developing an addiction. All

these genes are hard to genotype and

that is why it is so hard to say if

someone has a bigger chance in

developing an addiction.

Not only our genes play a role when it

comes to addiction, our environment

plays a big role as well. By environment

we mean friends, family, school, sports

etc. Our environment is 60% influential

and our genes 40%. So even when you

have "bad" genes you do not have to

develop an addiction when living in a

"good" environment. It also applies the

other way around; when you do not

have the "bad" genes but live in an

environment where having an addiction

is very likely, you can also get an

addiction.

So, when it comes to a smoking

addiction, it really depends on what

kind of person you are. Cigarettes are

easily available for almost all ages,

even though it is illegal for people under

the age of eighteen, which is also a big

factor when it comes to addiction. You

can get your hands on cigarettes easier

than getting your hands on, for

example, heroin.

When looking at the bigger picture, not

much research has been done when it

comes to what the effect of genes is on

a smoking addiction. But it has been

proven that genes do have an impact on

a lot of actions.


5. DISCUSSION

When looking at our whole paper, we

were happy with the subject we were

doing research on. The subject suited us

both and we were genuinely interested.

The cooperation between us was also

very good, since we never argued or

had any problems during this project.

We first wanted to research DNA of

adolescents who smoked and compare

their DNA and environment, but there

was too little time and it would cost too

much money. That is why we decided to

interview an expert on the subject: Prof.

dr. Verweij. She told us a lot of valuable

information for our main question, some

of which is not even published yet. We

were also very happy with her

cooperation.

We sincerely hope our research caught

your attention and helped you

understand how addictions and genes

can influence each other.

PWS Visser 2018-2019

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