In order for an individual to be diagnosed with major depressive disorder, (s)he must show signs of severe depressive symptoms for a period of at least __________

In Sarasota, Florida, a visitor might find all of the following EXCEPT:

A) more residents in their seventies and above. B) people who say those in their sixties are relatively young. C) residents who see "later life" as starting at an older age. D) mostly midlife adults.

Research suggests that the two most basic states of sleep are

a. alpha sleep and beta sleep. b. light sleep and deep sleep. c. REM sleep and non-REM sleep. d. REM sleep and paradoxical sleep.