Answer :
Brad suffers from schizophrenia and frequently sees people who are not actually there. this is an example of a hallucination.
What is schizophrenia?
Schizophrenia is a severe mental illness inside which existence is perceived by sufferers strangely.
When combined with hallucinations and disturbing thoughts and behaviors, psychosis can have a crippling effect on usual activities.
As brad sees the people who are not there in reality, this may be a hallucination as this can be termed as a dangerous situation and a risky one for the others and himself too.
Learn more about schizophrenia, here:
https://brainly.com/question/23035586
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