2-3 Simplified Health Measurement Scale This scale is developed to test the general mental health of the public, including five question as "do you feel nervous and anxious", "easily to feel worrisome and angry", "feeling depressed and sad", "feeling of low self-esteem" and "bad sleeping quality". Also, the investigators ask extra question as "do you have any suicide idea". This reliability and validity was proved by Li et al.,(2003), and it's a simple, convenient scale to screen out the potential depression tendency and suicide risk. The goal the investigators use this scale in the research is to improve the recognitions of nurses on Major Depression.