Final answer:
Severely mentally ill refers to individuals with chronic and impairing conditions such as schizophrenia, bipolar disorder, and severe depression, and is not typically used to describe personality disorders.
Step-by-step explanation:
The term "severely mentally ill" typically refers to those individuals suffering from schizophrenia, bipolar disorder, severe and recurrent depression, and other delusional disorders. These are chronic and severe mental health conditions that greatly impair an individual's ability to think, feel, and interact with others, and significantly impact their daily living. The American Psychiatric Association outlines these conditions in the Diagnostic and Statistical Manual of Mental Disorders (DSM), which is widely used to classify and diagnose mental illnesses. While personality disorders can have a pervasive impact on a person's life, they are generally not included under the term "severely mentally ill" which is focused more on the conditions such as schizophrenia and mood disorders like bipolar disorder and major depression