An abnormally strong emotional reaction to the perceived, threatened, or actual loss of a loved person or object to someone else. Morbid jealousy most often arises in relationships between spouses or lovers when one partner senses that a competitor is winning the loved one’s affections. Morbid jealousy can result in violence. It is estimated that one of every three to five murders involves jealousy.
Obsessive thoughts about a partner’s possible unfaithfulness are characteristics of morbid jealousy. Typically, the individual, often a man, becomes certain that his partner is being unfaithful. This condition can arise from personality disorders, depression, or paranoia. It might also stem from alcohol dependence or issues related to brain dysfunction.