PSYC 4039 Lecture Notes - Lecture 6: United States Census Bureau, Retrospective Diagnosis, Deinstitutionalisation
Document Summary
Prevalence is the % or proportion of a population that has a disorder at some point in time or during some interval of time: prevalence is affected by duration of the disease. If duration increases (e. g. , due to decrease effectiveness of treatment) prevalence increases. Prevalence goes up as the chronicity of the disease increases. If duration decreases (e. g. , increasing death rates) prevalence decreases. Incidence is the number of new cases that occur in a period of time: it is not the percent of people who have mental illness, only new cases. The relation between prevalence and incidence can be complicated, e. g. , the common cold has high incidence but low prevalence. There is something of a bias against thinking that mental illnesses can emerge and disappear (healy et al. , 2012, p. 9) Almost everyone who has written about insanity in the past half century has assumed that insanity"s increase was not real (torrey & miller, 2001, p. 316)
