Controlled studies indicate that
A)phototherapy is effective in alleviating cases of SAD.
B)low levels of negative ions are effective in most cases of SAD.
C)phototherapy is not effective in alleviating symptoms of SAD.
D)20 percent of the population or more suffer from SAD.

Question

Quizplus · Accepted Answer

Controlled studies have shown that phototherapy, also known as light therapy, is effective in alleviating symptoms of SAD (Seasonal Affective Disorder). It involves exposure to bright light, typically using a specially designed light box, for a period of time each day. Low levels of negative ions have not been shown to be effective in most cases of SAD, and the prevalence of SAD in the population is estimated to be around 5 percent, not 20 percent or more.

Controlled Studies Indicate That