Psychological kin is a separate term from copingkin. 

Otherkin are people who believe they literally are or were a fictional character for some reason. These reasons are either spiritual, or psychological. Otherkin have no control over who they are kin of, it is a revelation to them that they must accept or deny.

Copingkin are a separate category. They are people who use fictional identities to help them deal with mental illness.

Copingkin are perfectly legitimate, but they are not actual kin.

Psychological kin are real kin who for whatever reason don’t believe in souls/magic.