Narrator:       This is Science Today. Getting enough sleep is vital for good health, but as we age, depth of sleep actually decreases. Dr. Michael Irwin, a professor of psychiatry at UCLA says there are a number of factors that predict problems with sleeping besides biological processes.

Irwin:             There are what we call psychosocial or psychological processes that contribute to this impairment in sleeping. Significant stressors occur as we age - we may have lost our spouse and so that stress in and of itself is also a significant factor.

Narrator:       Adding to this, the elderly are at greater risk for developing depression and often take a number of medications that affect sleep. Yet, Irwin has found that practicing a simple, Westernized form of tai chi, promotes better sleep in older adults.

Irwin:             We found improvements in the overall sleep quality - people found that their sleep was more restful and the overall maintenance of sleep, that is, the amount of time that people were waking up throughout the night.

Narrator:       For Science Today, I'm Larissa Branin.