morbid
adj.adj. having a strong interest in dark or unpleasant subjects, especially death or disease. You use it to describe someone who thinks about sad or scary things too much.
adj. characterised by an abnormal or unhealthy interest in disturbing and unpleasant subjects, particularly death and decay. Often describes a psychological state or a specific fascination.
He has a morbid interest in true crime stories.
The old house had a morbid atmosphere that made the visitors feel uneasy about its history.
While some found the exhibition on Victorian funeral rites educational, others were put off by what they perceived as a morbid obsession with the physical reality of the grave.
From Latin morbidus (“diseased”), from morbus (“sickness”), itself from the root of morī (“to die”) or directly from Proto-Indo-European *mer- (“to rub, pound, wear away”).
Often follows linking verbs like 'seem' or 'become'; frequently modifies nouns like 'curiosity', 'fascination', or 'humor'.