I know it sounds comical, but yes it is an actual word. As published in Webster’s New Millennium Dictionary of English (v 0.9.7), a negaholic is defined as “a person who thoroughly enjoys a negative or pessimistic outlook; completely negative or pessimistic”.
When I first heard the term, I must admit, it made me laugh. But it is a brilliant word that describes people we all know who destroy vision, create turmoil within teams and attempt to recruit others into their circle of negativity. They thrive in situations rich with opportunity and work hard to uncover chances to point out their negative views. They never see opportunities. They only see worse case scenario. They turn potential into risk. They transform entrepreneurial spirit into doubt and fear. They are most commonly known as those who constantly view the glass as half empty.