7 Unexpected Signs of Stress

Why it could be stress: Stress can make you feel impulsive (it affects brain areas that keep our behavior in check), but it can also make you feel the opposite way, triggering withdrawal and a loss of confidence that's usually most noticeable at the office, says Susan Evans, PhD, professor of psychology in clinical psychology at Weill Cornell Medical College. "You may find yourself in a meeting where you'd normally voice your opinions without hesitation, but now you're holding back because you're not sure if what you have to say makes sense," she says. A small study in Neurocase found that simply watching a stressful movie for 30 minutes (in this case, Saving Private Ryan) made it harder to complete challenging word-association tasks than viewing more lighthearted fare.

Other possible causes: You guessed it—depression. Withdrawal is a classic symptom, but usually comes with other signs like a loss of interest in your favorite activities, feelings of hopelessness or changes in appetite.