Lifespan Development and Vulnerability to Mental Illness

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Assessing the Diathesis-Stress Model: Strengths and Weaknesses

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:05 Diathesis and Stress
  • 2:22 Addiction
  • 5:21 Wisdom
  • 7:00 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed
Lesson Transcript
Instructor: Natalie Boyd

Natalie is a teacher and holds an MA in English Education and is in progress on her PhD in psychology.

Biology and environment can influence if and when you develop a mental illness, but how do changes in our biology and environment affect us? In this lesson, we'll look at how changes affect our likelihood of developing psychological issues.

Diathesis and Stress

Fred is the life of the party. He loves to hang out with his friends at bars and parties. But recently, his drinking has gotten a little out of control. He doesn't remember things he did, and his grades in school are starting to suffer. Last week, his girlfriend threatened to break up with him if he didn't stop drinking. But, Fred just can't seem to stop.

Substance abuse disorders like alcoholism are only a small group of disorders studied by psychologists. And, just as there are a wide variety of disorders in psychology, there are also many different ways to approach those disorders. For example, some psychologists might say that Fred's problem is biological: He's inherited a gene from one of his parents that leads to addiction.

On the other hand, some psychologists might say that Fred's problem is that he has learned that he gets attention from his friends when he drinks. He has learned behaviors that are hard to break. Still other psychologists might say that Fred's problem is emotional. He deals with stress from life by drinking.

The diathesis-stress model of psychology says that a combination of vulnerability to a mental illness and life stress causes a person to develop a psychological disorder. For example, perhaps Fred did inherit a gene that causes a higher likelihood of becoming an addict. That doesn't mean that he absolutely will become an addict, only that he has a vulnerability, or diathesis, to addiction.

But then stress, emotional or physical, comes into play: He's getting pressure from his friends to drink to be cool, and he's worried about his midterms. These stresses, combined with his original vulnerability, lead him to being addicted.

You might have noticed that the stresses of Fred's life are specific to someone of a certain age. An eight-year-old is probably not going to experience a lot of peer pressure to drink alcohol, and someone who has left college and is out in the workforce is not going to be worried about midterms. As we grow and develop through our lives, the stresses and vulnerabilities that we have change. Let's look at some ways that the diathesis-stress model is influenced by development, including the areas of addiction and wisdom development.


Fred's drinking problem began when he was 16 and first started going to parties and drinking alcohol. But, the problem got even worse when he went off to college. Like many people, Fred's college experience gave him more freedom and less parental supervision than ever before in his life.

At the same time, he found even more peer pressure to go to parties and drink, and he felt even more anxious about life now that he was away from home. All of these are common experiences for college students, and all of them are added stress that can lead to addiction. Remember that the diathesis-stress model says that Fred has a vulnerability to addiction already. If he doesn't experience stress, or if he experiences only a little bit of stress, he will not become an addict. That vulnerability will lie dormant inside of him.

But, the more stress he experiences, the more likely it is that he will become addicted. Since many college students experience increased stress in the form of peer pressure and academic and life stresses, this is a time when many people end up succumbing to addiction.

It's not just addiction, either. The diathesis-stress model covers all sorts of psychological issues. For example, if a person has a diathesis for depression, they might discover that the pressures of college cause them to become depressed. Likewise, the mental disorder schizophrenia is usually first diagnosed between the ages of 18 and 25, which are the stressful college years for many people.

The diathesis-stress model and the high levels of stress during college can explain why drug and alcohol abuse are most common during the late teens and early twenties. After all, the stress part of the diathesis-stress model is increased at that point in life. But, what happens when your stress stays the same but your vulnerability increases?

One example of how the diathesis, or vulnerability, part of the diathesis-stress model can increase is in the high number of older adults who develop addictions. Unlike college students, who are experiencing lots of peer pressure to drink, the stresses that older adults face are different but not necessarily higher than those they have faced at other times in their lives.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account