Describe factors that may contribute to an individual being more vulnerable to abuse

1. Mental/Psychological illnesses such as depression, anxiety, schizophrenia, Anti-Social Personality Disorder - really just anything that can contribute to further trouble coping emotionally.
2. Low self-confidence/esteem.
3. A history of abuse (most commonly within childhood). 
4. Mindset (e.g someone might feel deserving of abuse, which would make them more vulnerable)

There are more, but here are some to get you started