Slow onset forgetting most recent events, inability to process new information, easily confused, can be depressed or anxious, lacking familiarity - these are the symptoms of which mental illness?

Dissociate identity disorder

Explanation:

Symptoms: memory loss, people, time, events...

Being detached from emotions and people.

Blurred sense of identity.

Depression, anxiety, suicidal thoughts...

Causes:

Multiple personality disorder is characterized by "switching" to other identities. A person might feel presence of more than one people talking or living inside one’s head. A person might feel like they are possessed by other identities. Every identity has a different name, personality and characteristics.

communicate with the patient and explain every step before proceeding to do so