Predictions of calamity (which rarely come to pass) and evil premonitions (which are most often false) instill fear into the hearts of many:
([Satan] threatens you with poverty and orders you to commit Fahsha [evil deeds, illegal sexual intercourse, sins etc.]; whereas Allah promises you forgiveness from Himself and Bounty and Allah is All-Sufficient for his creatures 'needs, All-Knower ( Qur'an 2: 268)
Anxiety, sleeplessness, and ulcers are the ill consequences of hopelessness and worry.
An Arab poet said:
"Don't punish us for we have already been tortured, By anxiety that keeps us awake long through the night."