Mental Health.net
mentalhelp.net/articles/dsm-5-the-ten-personality-disorders-cluster-c/

The core feature of the Dependent Personality Disorder is a strong need to be taken care of by other people. This need to be taken care of, and the associated fear of losing the support of others, often leads people with Dependent Personality Disorder to behave in a “clingy” manner; to submit to the desires of other people. In order to avoid conflict, they may have great difficulty standing up for themselves. The intense fear of losing a relationship makes them vulnerable to manipulation and abuse. They find it difficult to express disagreement or make independent decisions, and are challenged to begin a task when nobody is available to assist them. Being alone is extremely hard for them. When someone with Dependent Personality Disorder finds that a relationship they depend on has ended, they will immediately seek another source of support.