A psychological illness exists when

a person has delusions, thoughts or beliefs without a basis in reality.
thoughts and/or emotions prevent a person from functioning normally.
emotions like nervousness or sadness get out of control.
a person’s genetics cause him or her to develop schizophrenia or bipolar disorder.

Respuesta :

Thoughts and/or emotions prevent a person from functioning normally. The first one isn’t right as a person with mental illnesses may not have delusions, the same with the third one a person with mental illness may not be nervous or sad, and schizophrenia and bipolar are mental disorders but it is not limited to those.