Health & Parenting

Hormone May Boost Teen Mood Swings

March 12, 2007 -- Teen mood swings may be partly due to a hormone that calms kids and adults but makes stressed teens more anxious.

That news comes from lab tests on adolescent female mice, not teen girls.

Sheryl Smith, PhD, and colleagues designed the mouse model to mimic the teen brain. Smith is an associate professor of physiology and pharmacology at SUNY Downstate Medical Center in Brooklyn, N.Y.

Smith's team focused on a hormone called THP, which calms stressed children and adults. But THP may have the opposite effect in teens.

In a lab, the researchers studied baby, teen, and adult female mice. The scientists gauged the mice's anxiety level by seeing how fast the mice scurried out of an open area after being briefly restrained.

The baby and adult mice were less anxious when they received THP injections. But the stressed teen mice became more anxious with THP, the study shows.

Puberty brings a dramatic rise in highly sensitive brain receptors for a brain chemical called GABA, note Smith and colleagues. THP may make stressed teens more anxious by blocking those GABA receptors, the scientists suggest.

Adolescent males can also have mood swings, but this study didn't explore the brain chemistry of male mood swings.

The study appears in the advance online edition of Nature Neuroscience.