Most teen mood swings decline with age

Scientists have found that adolescents' mood swings decline gradually as they get older, a finding that can reassure parents about their moody teens while also helping them identify when instability may require intervention.
The study was conducted by researchers at VU University Amsterdam, the EMGO Institute for Health and Care Research, Utrecht University, and Tilburg University, in the Netherlands.
"We found that early adolescence is the period of the greatest volatility, but adolescents gradually stabilise in their moods," said Hans M Koot, professor of developmental psychology at VU University Amsterdam and the EMGO Institute for Health and Care Research, and a coauthor of the study.

"An important message to teens, parents, and teachers is that temporary mood swings during early adolescence might actually be normal and aren't necessarily a reason to worry," Koot said.
Researchers followed 474 middle- to high-income Dutch adolescents from ages 13 to 18. Forty per cent of these adolescents were at high risk for externalising behaviours (eg, 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).

Using these daily assessments, the researchers calculated fluctuations in day-to-day mood and then analysed whether these showed any developmental changes across the five-year period.

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.
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's likely that adolescents figure out over time how to deal more effectively with changes in their moods.
Anxiety was the only mood that didn't fit in with this overall pattern. The variability in teens' anxious moods waxed and waned, with an initial increase, then a decrease, followed by an increase again toward the end of adolescence.
This trend could be explained by the transition toward adulthood, the researchers suggest, which might induce more anxiety swings in late adolescence due to teens' increasing responsibilities (such as leaving school, going on to higher education, or getting a job).
The study appears in the journal Child Development.