The Causes of Noticeable Changes in a Teen's Personality

By Kay Ireland
Social changes can affect your teen's personality.
Social changes can affect your teen's personality.

It can seem like a 180-degree turnaround when your child goes from a cheerful, happy-go-lucky tween to a moody, surly and sullen teen. No, your teen hasn't been replaced by Dr. Jekhyll and Mr. Hyde, but he might be experiencing body, brain and social changes that can have a noticeable effect on his overall personality. By understanding the reasons behind these changes, you can better understand how to help, when to worry and when to relax.


Your teen is learning to assert his autonomy and sometimes that means absorbing various influences to make up his mind and opinions on everything from the music he likes to the clothes he wears. His friends can have a large bearing on his personality, especially because acceptance means a lot to your teen. He may alter his personality and tastes to fit in with a certain group at school or to emulate someone that he admires -- for better or for worse.


Going through puberty can do a number on your teen's moods, which can turn him from someone who is usually genial and optimistic to someone who is easily aggravated and grumpy. The influx of hormones during puberty can sometimes cause mood swings, notes, so you might find that your teen is in a good mood one moment and cranky and surly the next. He might also be reacting to the physical changes that have come along with puberty such as increased acne, body odor, body hair and even sexual responses.


Sometimes moodiness is much more than normal teen behavior. Teen depression can have a drastic effect on your teen's personality, resulting in symptoms such as a withdrawal from society, anxiety, changes in diet, problems sleeping and a lack of focus, according to licensed counselor Ugo Uche in an article for "Psychology Today." If you believe your teen is depressed, seek medical help immediately. Together, you, your doctor and your teen can choose a teen-appropriate treatment plan.

Substance Abuse

Using substances can drastically change the way your teen behaves around you. For example, he might have sudden changes in temper or have a complete change in his appearance. You might notice that he's more secretive than normal or spends time with a completely different group of peers. Jitters, aggression and defensiveness are also signs that your teen might be using various substances. If this is the case, the National Youth Network suggests getting help via treatment as soon as possible.

About the Author

Kay Ireland specializes in health, fitness and lifestyle topics. She is a support worker in the neonatal intensive care and antepartum units of her local hospital and recently became a certified group fitness instructor.