The stigmatization of mental illnesses has a long history, stemming from lack of knowledge and resources dedicated to studying mental health disorders. For much of recorded history, people diagnosed with a mental illness were isolated apart from the public, often believed to be possessed by a demon or manipulated by witchcraft. Mental illness was often viewed by the public as a failure of character or upbringing, provoking those who suffered from them to feel shame and guilt. The extreme end of available treatments subjected patients to torture, experimentation, or sterilization.

Recent decades have seen improvement in public policy and greater awareness of some mental illnesses, principally depression, but others have continued to be stigmatized. Recent studies have shown that even when people understand that a mental illness stems from genetics and brain chemistry, they may be reluctant to associate with those diagnosed with certain mental illnesses, including schizophrenia and bipolar disorder, both of which can include psychotic episodes.

One of the main characters in Dreamland, Paige Beverly Mills has bipolar I disorder, a mood disorder characterized by manic and depressive episodes, sometimes alternating and sometimes experienced simultaneously. During periods of mania, a person may experience feelings of euphoria, increased energy and activity, and irritability.