Evidence is accumulating that the occurrence of severe psychiatric disorders, especially schizophrenia and bipolar disorder, may be increasing. The most visible manifestation of this is the increasing number of severely mentally ill individuals among the homeless population and in the nation's jails. Multiple studies have reported that at least one-third of the approximately 600,000 homeless individuals have a severe psychiatric disorder, and there are suggestions that the problem is getting worse.Similarly, a 1999 U.S. Department of Justice study reported that 16% of inmates in local jails and state prisons -- 275,900 individuals -- had been treated psychiatrically (Ditton, 1999). There are, therefore, five times more psychiatric patients in jails and prisons than the 55,000 remaining patients in state psychiatric hospitals. Headlines are increasingly proclaiming statements such as: "Mental Illness Behind Bars: A Tragic Situation Getting Worse" (Kupers, 2000).
Another measure of the increasing number of individuals with severe psychiatric disorders is the number of these individuals on supplemental security income (SSI) and social security disability insurance (SSDI), the two federal programs for the support of disabled individuals. The number of individuals in the category "mental disorders other than mental retardation" increased from 1.1 million in 1985 to 2.9 million in 1998, a 164% increase during a time in which the U.S. population increased only 13%. The "mental disorders" category is both the largest and the fastest-growing diagnostic category for both the SSI and SSDI programs.
Increasing numbers of individuals with severe psychiatric disorders are also suggested by the experience of managed care companies assuming responsibility for state psychiatric programs. In state after state, managed care companies have underestimated the number of individuals with severe psychiatric disorders who require services, with dire fiscal consequences. Typical is a statement from the press regarding the January report from the state of Maryland discussing the failed managed care program for Maryland's mentally ill Medicaid patients: "But the state greatly underestimated demand, and the system was soon overwhelmed" (Becker and Hedgpeth, 2002).
The strongest evidence that severe psychiatric disorders may be increasing comes from the Epidemiologic Catchment Area (ECA) study, carried out in the early 1980s, and the National Comorbidity Survey (NCS), carried out in the early 1990s. In a 1999 discussion, Darrel Regier, M.D., co-author of the ECA study, said the study found that, after accounting for duplicate diagnoses, 2.2% of adults (ages 18 years and over) met diagnostic criteria for schizophrenia or bipolar disorder over a one-year period. A recent reanalysis of this study revised this estimate to 1.7% (Narrow et al., 2002). This translates into a prevalence rate of 12 to 16 per 1,000 total population, not including any mentally ill adults with other severe psychiatric disorders such as major depression or severe obsessive-compulsive disorder. The NCS study reported that 2.6% of adults had a "severe and persistent mental illness [SPMI]," defined as including schizophrenia; bipolar disorder; severe forms of depression, panic disorder and obsessive-compulsive disorder; and autism (Kessler et al., 1996). This translates into 19 adult individuals with SPMI per 1,000 total population.
Although comparisons of rates over time are fraught with diagnostic and other methodological pitfalls, the 12 to 19 per 1,000 rate contrasts sharply with prevalence surveys done in earlier years. For example, the 1958 Hollingshead and Redlich study of New Haven, Conn., one of the ECA study sites, reported a rate of 4.2 individuals who were being treated for schizophrenia and affective psychoses per 1,000 total population. Similarly, a census study of Baltimore, another ECA study site, found a rate of 7.1 individuals with psychosis or with psychotic traits, both treated and untreated, per 1,000 total population (Lemkau et al., 1942).
The most complete enumeration of severe psychiatric disorders ever carried out by the U.S. Census Office was done in 1880. Because of widespread fears at the time that insanity was increasing, census enumerators were given special forms and extra pay to identify all severely mentally ill people, including querying neighbors of the person in question. In addition, all 100,000 physicians in the United States were asked to report "all idiots and lunatics within the sphere of their personal knowledge," and over 80% did so. Insanity was classified by seven subtypes using definitions supplied by the New England Psychological Association. All duplication between the enumerator and physician lists was eliminated.
A total of 91,997 insane people were identified. Of these, 38,047 were in asylums, an increase of 115% in hospitalized insane since the 1870 census. The prevalence of insane people, both hospitalized and living in the community, was 1.83 per 1,000 total population. In 1880, asylum superintendent Foster Pratt called that increase an "important and alarming factåa great question of public health that demands careful study" (as cited in Grob, 1980). And yet the ECA study from 1980 reported a prevalence rate for schizophrenia and bipolar disorder that was almost 10 times higher than the 1880 prevalence rate.