Addiction-Prone Personality (Drugs, Gambling, Alcohol, Nicotine)

Addiction is one of the serious problems in modern society.

Many people become dependent on alcohol, nicotine, cannabis, gambling, etc., causing problems in their health and social life.

In this context, research focusing on the relationship between addiction and personality traits was conducted.

An Australian research team investigated the relationship between four types of addiction and five personality traits in 3,785 twins and siblings.

The research results were published in a paper titled “Big Five Personality Traits and Alcohol, Nicotine, Cannabis, and Gambling Disorder Comorbidity“.

This research aims to deepen understanding of addiction and provide insights useful for prevention and treatment.

By clarifying the relationship between addiction and personality traits, it may be possible to detect addiction risks early and connect to appropriate interventions.

This article provides an easy-to-understand explanation of the overview and main results of this research.

Once again, personality researcher and author of Villain Encyclopedia, Tokiwa (@etokiwa999), will provide the explanation.
※We have developed the HEXACO-JP Personality Assessment! It has more scientific basis than MBTI. Tap below for details.

The Relationship Between Addiction and Personality Traits

Overview of Addiction Research

This research aims to explore the relationship between addiction and personality traits.
Specifically, it investigated the relationship between the following four types of addiction and the Big Five.

• Alcohol addiction
• Nicotine addiction
• Cannabis addiction
• Gambling addiction

It also focuses on comorbidity between addictions.
That is, it analyzed the proportion of people with multiple addictions simultaneously and how personality traits influence such comorbidity.
This research aims to deepen understanding of addiction and provide insights useful for prevention and treatment.
By clarifying the relationship between addiction and personality traits, it may be possible to detect addiction risks early and connect to appropriate interventions.

Details of Addiction Survey Subjects

This research was conducted on 3,785 twins and siblings registered in the Australian Twin Registry.
The breakdown is as follows:

• Males: 1,365 people
• Females: 2,420 people
• Average age: 32 years old
• Age range: 21-46 years old

In other words, it includes a wide age range from young adults to middle-aged people.
Also, by targeting twins and siblings, there is an advantage of being able to separately consider genetic and environmental influences.
However, since it targets a specific population in Australia, caution is needed when generalizing the results.
In the future, similar research in other countries and cultural spheres is expected to accumulate knowledge.

The Four Types of Addiction Investigated

This research investigated the following four types of addiction.

1. Alcohol addiction
2. Nicotine addiction
3. Cannabis addiction
4. Gambling addiction

These are all addictions that have become serious problems in modern society.
Alcohol and nicotine are legal substances of choice, but excessive use leads to health damage.
Cannabis is an illegal drug, raising concerns about mental health risks.
Gambling, when one becomes obsessed, can lead to economic ruin.
Clarifying how these addictions relate to personality traits will provide important insights for addiction prevention and treatment.

What are the Big Five Personality Traits

The Big Five is a theory that captures personality through five major traits.
It consists of the following five traits:

1. Neuroticism: Emotional instability such as anxiety and depression
2. Extraversion: The degree of sociability and assertiveness
3. Openness: Tolerance for new experiences and ideas
4. Agreeableness: Empathy for others and cooperative attitude
5. Conscientiousness: Self-control and faithfulness to goals

These traits are thought to be formed under the influence of both genetics and environment.
Also, the strength of traits varies greatly among individuals and cannot be judged as good or bad in general.
However, when specific traits are too extremely high or low, they may lead to mental health problems.
By exploring relationships with addiction, it may become clear how personality traits influence addiction risk and recovery.

ビッグファイブ(Big Five)診断とは？概要・遺伝・MBTIとの関連

The Relationship Between Addiction and Neuroticism

Neuroticism was related to all four addictions.
People high in this tendency tend to feel anxiety and stress easily.
Therefore, the following mechanisms are thought to increase addiction risk:

• To distract from anxiety and stress, they rely on alcohol or drugs.
• To escape from negative emotions, they become absorbed in gambling.
• Seeking mental stability, they become dependent on nicotine.

However, having high neuroticism does not necessarily mean one will develop addiction.
By learning appropriate stress coping methods, it may be possible to reduce the risk of addiction.
Also, in the recovery process from addiction, controlling anxiety and stress will be important challenges.
Understanding the relationship between neuroticism and addiction is considered helpful for addiction prevention and treatment.

神経症傾向とは？ビッグファイブ診断・MBTIとの関連など解説

Relationship Between Addiction and Extraversion

The relationship between extraversion and addiction showed different results depending on the type of addiction.
For alcohol addiction and gambling addiction, no clear relationship with extraversion was observed.
On the other hand, for nicotine addiction and cannabis addiction, a tendency was shown where lower extraversion increased the risk of addiction.
Low extraversion means poor sociability and introverted personality.
These characteristics may increase the risk of addiction through the following mechanisms.

• Due to limited social interaction, they rely on drugs to dispel loneliness.
• Due to their introverted personality, stress coping methods become limited.

However, high extraversion does not reduce the risk of addiction.
Even sociable people can potentially rely on alcohol or drugs.
It was suggested that the relationship between extraversion and addiction differs depending on the type of addiction.

内向的な性格とは？具体的な強みを研究をもとに解説

Relationship Between Addiction and Openness

The relationship between openness and addiction also showed different results depending on the type of addiction.
For alcohol addiction, nicotine addiction, and gambling addiction, no clear relationship with openness was observed.
On the other hand, for cannabis addiction, a tendency was shown where higher openness increased the risk of addiction.
High openness means a tendency to seek new experiences and sensations.
These characteristics may increase the risk of cannabis addiction through the following mechanisms.

• Seeking novelty, they end up wanting to try cannabis.
• Seeking extraordinary sensations, they repeatedly use cannabis.

However, high openness does not directly cause cannabis addiction.
It is considered merely one risk factor that makes high openness more likely to trigger cannabis use.
It was suggested that the relationship between openness and addiction may be specific to cannabis addiction.

開放性とは？ビッグファイブ診断・MBTIのNとSとの関連など

Relationship Between Addiction and Agreeableness

Agreeableness was related to all four types of addiction.
However, this relationship was not as strong as with neuroticism.
People with low agreeableness tend to have poor empathy toward others and lack a cooperative attitude.
These characteristics may increase the risk of addiction through the following mechanisms.

• They cannot accept support or advice from others.
• They cannot build cooperative relationships necessary for recovery.
• They are prone to addiction due to feelings of isolation.

However, low agreeableness does not directly cause addiction.
It is considered to influence addiction risk through interaction with other personality traits and environmental factors.
The relationship between agreeableness and addiction can be said to be one factor that should be considered in addiction prevention and treatment.

協調性とは？ビッグファイブ診断・MBTIのFとTとの関連など

Relationship Between Addiction and Conscientiousness

Conscientiousness was also related to all four types of addiction.
People with low levels of this trait tend to have poor self-control and lack loyalty to goals.
These characteristics may increase the risk of addiction through the following mechanisms.

• They cannot suppress impulsive behavior.
• They prioritize short-term pleasure over long-term goals.
• They cannot continue the effort necessary for recovery from addiction.

However, low conscientiousness does not directly cause addiction.
It is considered to influence addiction risk through interaction with other personality traits and environmental factors.
The relationship between conscientiousness and addiction can be said to be one factor that should be considered in addiction prevention and treatment.
In particular, support for enhancing conscientiousness may be important during the recovery process.

誠実性とは？ビッグファイブ診断・MBTIのJとPとの関連など

About Comorbidity of Addiction

Comorbidity Rate of Addiction

This study revealed the high comorbidity rate among different addictions.
54% of the survey participants met the diagnostic criteria for at least one addiction.
The breakdown is as follows.

• One addiction only: 30%
• Two addictions: 15%
• Three addictions: 8%
• Four addictions: 0.55%

In other words, nearly half of people with addictions had multiple co-occurring addictions.
Particularly among men, the proportion of those with two or more addictions was higher.
The comorbidity of addictions is considered one of the factors that makes treatment difficult.
It is necessary to consider prevention and treatment approaches taking into account the high comorbidity rate of addictions.

“Pure” addictions are rare

This study revealed that “pure” addictions, meaning addictions without co-occurring other addictions, are rare.
In particular, “pure” cases were extremely rare for cannabis addiction and gambling addiction.
For cannabis addiction, comorbidity with alcohol and nicotine was commonly observed.
For gambling addiction, comorbidity with alcohol and nicotine was commonly observed.
Such comorbidity patterns may be related to the following factors:

• Common brain mechanisms that cause addiction
• Similarity of social problems caused by addiction
• Existence of personality traits that predispose to specific addictions

The rarity of “pure” addictions provides important implications for addiction treatment.
A comprehensive approach will be necessary based on the premise of addiction comorbidity.

喫煙しやすい人、禁煙しやすい人：性格の違いを論文で解説

Multi-comorbidity of two or more addictions is common

This study revealed that multi-comorbidity of two or more addictions is common.
23.55% of survey participants showed patterns of multi-comorbidity.
The breakdown is as follows:

• Two addictions: 15%
• Three addictions: 8%
• Four addictions: 0.55%

Particularly among men, the proportion of multi-comorbidity was higher.
Multi-comorbidity is considered one indicator of addiction severity.
The intertwining of multiple addictions may reduce motivation for treatment and increase the risk of relapse.
Understanding patterns of multi-comorbidity will have important implications for addiction prevention and treatment.
A comprehensive perspective is required, not just focusing on individual addictions.

Considering personality traits weakens the relationship between addictions

This study revealed that when personality traits are considered, the relationships between addictions weaken.
Specifically, when statistically controlling for the five Big Five traits, the relationships between addictions changed as follows:

• Men: Relationships decreased by 2-53%
• Women: Relationships decreased by 2-45%

Particularly, the relationship between alcohol addiction and gambling addiction decreased significantly.
On the other hand, the relationship between cannabis addiction and nicotine addiction was not much affected by personality traits.

Relationship between alcohol addiction and gambling addiction

This study revealed that the relationship between alcohol addiction and gambling addiction was most significantly affected by personality traits.
In men, considering personality traits reduced the relationship between the two by 53%.
In women, a 45% reduction was observed.
This suggests that personality traits play an important role in the comorbidity of alcohol addiction and gambling addiction.
Specifically, the following personality traits may influence the comorbidity of both:

• High neuroticism
• Low conscientiousness
• High impulsivity

To prevent comorbidity of alcohol addiction and gambling addiction, interventions focusing on these personality traits may be effective.
During treatment, approaches that take personality traits into consideration will also be required.

お酒が好きな人の性格とは？論文を紹介して解説

Gender differences in the relationship between addiction and personality traits

Results for addiction are generally similar between men and women

This study found no major gender differences in the relationship between addiction and personality traits.

For alcohol addiction, nicotine addiction, and cannabis addiction, there were almost no gender differences in the relationship with personality traits.

The tendency for higher neuroticism, agreeableness, and conscientiousness to increase the risk of these addictions was common to both men and women.

This suggests that the mechanisms by which personality traits work as risk factors for addiction may be similar for both men and women.

However, the prevalence of addiction itself was higher among men.

Factors other than personality traits, such as social or biological factors, may be involved in gender differences in prevalence.

Regarding the relationship between addiction and personality traits, it was suggested that there are no major differences between men and women.

Some Gender Differences in Gambling Addiction

Regarding the relationship between gambling addiction and personality traits, some gender differences were observed.

Specifically, the association between gambling addiction and neuroticism and extraversion was stronger in women.

In gambling addiction among women, personality traits of high neuroticism and low extraversion may work more strongly as risk factors.

On the other hand, in gambling addiction among men, the association with these personality traits was relatively weaker.

Additionally, gender differences were suggested in the patterns of comorbidity between gambling addiction and other addictions.

In women, comorbidity of gambling addiction with nicotine addiction and cannabis addiction was observed more frequently than in men.

Regarding the relationship between gambling addiction and personality traits, it became clear that gender differences exist in some aspects.

The need for prevention and treatment approaches that consider gender is suggested.

ギャンブルをやりやすい性格・見抜き方を科学的に解説

About the Severity of Gambling Addiction

Severity of Gambling Addiction from Effect Size Perspective

This study revealed that the impact of gambling addiction on personality traits is greater than that of other addictions.

The effect size showing the association with personality traits was largest for gambling addiction.

While the effect sizes for alcohol addiction, nicotine addiction, and cannabis addiction were relatively small, gambling addiction showed very large values.

From this, based on the current “DSM diagnostic criteria (Diagnostic and Statistical Manual of Mental Disorders),” the severity of gambling addiction may be higher than other addictions.

The diagnostic criteria for gambling addiction may be too strict compared to other addictions.

Additionally, the magnitude of gambling addiction’s impact on personality traits may reflect the seriousness of this disorder.

To appropriately evaluate the severity of gambling addiction, reconsideration of diagnostic criteria is considered necessary.

Possibility of Adjusting DSM Diagnostic Criteria (Diagnostic and Statistical Manual of Mental Disorders)

The results of this study suggest the need to adjust the DSM diagnostic criteria for gambling addiction to a severity level equivalent to other addictions.
Specifically, the following adjustment proposals can be considered.

• Reduce the number of symptoms required for diagnosis (e.g., 5 → 3)
• Establish subcategories according to severity (e.g., mild, moderate, severe)
• Take into account comorbidity with other addictions

By making such adjustments, the diagnostic criteria for gambling addiction may come to reflect severity levels equivalent to other addictions.
Additionally, adjustments to diagnostic criteria may also impact gambling addiction treatment guidelines.
For example, treatment goals and intervention methods may be set according to criteria similar to those for other addictions.
Adjustment of DSM diagnostic criteria is considered an important issue for appropriate evaluation and treatment of gambling addiction.

Multiple Comorbidity of Addictions and Personality Traits

The More Addictions, the Stronger the Association with Personality Traits

This study revealed that the more addictions present, the stronger the association with personality traits.
Specifically, the following tendencies were observed.

• Neuroticism, agreeableness, conscientiousness: The more addictions, the stronger the association with these traits
• Extraversion: Decreases with two or more addictions
• Openness: Increases with three or more addictions (women only)

From this, multiple comorbidity of addictions may be a factor that strengthens the association with personality traits.
In other words, people with specific personality traits may be more likely to develop multiple addictions.
Additionally, developing multiple addictions may further emphasize personality traits.
The relationship between multiple comorbidity and personality traits provides important implications for addiction prevention and treatment.
Particularly for people at high risk of multiple comorbidity, interventions focusing on personality traits may be effective.

Limitations of Addiction Research and Future Prospects

Limitations Regarding Representativeness of Addiction Samples

This study was conducted using data from an Australian twin registry.
Therefore, it has the following limitations.

• Does not necessarily represent the general population within Australia
• Results may not apply to other countries or cultural spheres
• Targets the special population of twins

Given these limitations, caution is needed when generalizing the results of this study.
In the future, similar studies should be conducted in other countries and cultural spheres to confirm the reproducibility of results.
Research targeting general populations is also needed.
Sample representativeness is one limitation of this study, but it may be overcome by future research.

Need for Further Research Including Other Addictions

This study examined four addictions: alcohol, nicotine, cannabis, and gambling, but other addictions were not considered.
For example, the following addictions also exist.

• Prescription drug abuse
• Internet addiction
• Shopping addiction
• Sex addiction

The relationship between these addictions and personality traits will also need to be examined in the future.
Additionally, the relationships and comorbidity patterns among addictions themselves need to be investigated in more detail.
Including other addictions might deepen our understanding of addiction as a whole.
New insights that are useful for addiction prevention and treatment might also be obtained.
Further research including other addictions can be said to be one of the important challenges for the development of this field.

ネット依存になりやすい性格を科学的に解説

The Importance of Longitudinal Studies in Addiction

This study was conducted using a cross-sectional research design.
In other words, it analyzed data from a single point in time.
Therefore, it has the following limitations.

• Cannot clarify causal relationships
• Cannot capture changes in personality traits associated with the onset and progression of addiction
• Cannot determine whether personality traits precede addiction or whether addiction influences personality traits

To overcome these limitations, longitudinal studies are necessary.
In other words, tracking the same people over a long period and capturing the relationship between addiction and personality traits chronologically.
Longitudinal studies may provide the following insights.

• Whether personality traits increase the risk of developing addiction
• Whether addiction changes personality traits
• How the relationship between addiction and personality traits changes over time

Longitudinal studies are considered to play an important role in understanding the relationship between addiction and personality traits.

Final Summary of Addiction

This study revealed several important insights about the relationship between addiction and personality traits.

First, it was found that three personality traits – neuroticism, agreeableness, and conscientiousness – are associated with all four addictions: alcohol, nicotine, cannabis, and gambling.

It was also revealed that many people have multiple addictions simultaneously, and that “pure” cases are particularly rare in cannabis addiction and gambling addiction.

This study can be said to be an important step that deepens our understanding of addiction and provides clues for prevention and treatment.

In the future, further research including other addictions and research from a long-term perspective are needed.

Addiction is not just an individual problem, but a challenge that society as a whole should address.

It is important for each individual to deepen their understanding of addiction and expand the circle of support.

※This article is written with reference to papers published in the following book.