Experts say the key to coping with psychological terror is to find a healthy balance.
"When people are stressed, there is a temptation to lose touch with reality and to blur the boundary between reality and fantasy," says Haroun.
He says the reality might be that the chance of becoming a victim of terror is very small, but the fantasy is, "Oh my, it's going to happen to me and happen to everyone."
"If you blur that line and start making decisions on false data," says Haroun, "that's going to lead to bad decision making."
He says the first thing is to stay grounded in reality, seek out reliable sources of news and information, and don't rush to make quick judgments based on incomplete or inaccurate information.
"Because we are people, our decision-making skills can be impaired in times of extreme stress, so the trick is to talk to wise people," says Haroun.
That could be a trusted family member, counselor, clergy, or other person who has sound judgment.
The second thing to do is reduce your stress level. The easiest way to do that is to talk about the stress and fear you're feeling with someone else.
Trauma expert Charles Figley says that people often fall into two camps after experiencing trauma: overreaction or underreaction.
"If we overreact in an emotional way, then we're not thinking very logically and clearly, and we could benefit from thinking it through rationally," says Figley. "If we only go to the rational part and don't think about the humanity and the emotions, then we are also denying sensitivity to that and awareness of how we may be responding, perhaps not now but eventually on an emotional level."
Figley and Haroun say it's worth asking yourself why you might be under- or overreacting to a particular situation because it may be related to something in your subconscious.
"It may be associated with one's own fear of death, you may be still grieving a previous death, or fearful for a relative in military service," says Figley. "Then that's where you put your attention, not where it started but where it led you."