London, Oct 15 (IANS): Adolescents' mood swings decline gradually as they get older, finds a new study that is reassuring to parents about their moody teens.

The findings would also help identify when instability is considered risky and requires intervention. Adolescence is typically regarded as a period of heightened emotionality.

"We found that early adolescence is the period of the greatest volatility, but adolescents gradually stabilise in their moods," said study co-author professor Hans M. Koot from VU University Amsterdam.

During the course of adolescence, teens' moods became more stable for happiness, anger, and sadness, the study found.

Although girls had higher variability than boys in happiness and sadness, the rate of change across adolescence was similar for both sexes.

"An important message to teens, parents, and teachers is that temporary mood swings during early adolescence might actually be normal and are not necessarily a reason to worry," Koot added.

Researchers followed 474 middle- to high-income Dutch adolescents from ages 13 to 18. Forty percent of these adolescents were at high risk for externalising behaviours (e.g., aggressive or delinquent behaviour) at age 12.

Using internet diaries, the teens rated their daily moods in terms of happiness, anger, sadness, and anxiety during three weeks of the school year for five years (that is, a total of 15 weeks spread over five years).

The researchers posited that teens' moods could become more stable because events that are new in early adolescence (such as first romances, which can be exciting, and conflicts with parents about leisure time, which can be frustrating) happen less frequently as teens grow older.

And it is likely that adolescents figure out over time how to deal more effectively with changes in their moods.

"Teens who continue to be extremely moody or who get even moodier across adolescence may need to be monitored more closely since earlier studies have shown that extreme mood swings are related to more emotional, behavioural, and interpersonal problems," said first author Dominique F. Maciejewski from VU University.

The findings were published in the journal Child Development.