With the widespread availability of HAART for HIV infection in developed countries occurring in the mid-1990s, rates and reasons for medical hospitalization of HIV-infected patients have changed. Multiple studies conducted after the dissemination of HAART documented dramatic declines in inpatient censuses, ranging from 33% to 75%, occurring primarily between 1995 and 1997.¹,²,³,⁴ In the late 1990s and early 2000s, rates stabilized or rebounded slightly.

Data on the changing reasons for medical hospital admissions reflect the impact of HAART on AIDS-related opportunistic infections and cancers. In two urban hospital studies, a uniform drop in hospital admissions due to opportunistic infections and cancers was observed, contrasting with a rise in nonopportunistic complications.³,⁴ Mean CD4 counts of HIV-infected inpatients were seen to increase by over 100 cells/mm³ from 1995 to 2001.³

Factors that appear to confer risk for medical hospitalization in the HAART era include low CD4 count, female gender, lack of antiretroviral treatment, and injection drug use.³,⁴ The sociodemographic characteristics of those at risk reflect the shifting demographics of the HIV epidemic, limited access to care, and adherence to antiretroviral treatment.

In contrast to the extensive epidemiologic data for psychiatric disorders in ambulatory patients with HIV infection or AIDS, there are relatively few data on rates of psychiatric disorders among medical inpatients. Nearly all published studies describing outcomes of psychiatric consultations in inpatients with HIV disease or AIDS in the pre-HAART era include small samples and do not employ standardized psychiatric diagnostic instruments. Despite these limitations, available data reflect those clinical problems that the consulting psychiatrist is most likely to encounter.

Table 19.1 summarizes the literature to date.⁵,⁶,⁷,⁸,⁹ Across studies, the most frequently diagnosed disorders are in the depressive spectrum (range 27% to 83%), including depression secondary to medical condition (or organic mood disorder), major depressive disorder, or dysthymic disorder. Delirium is diagnosed in 8% to 29% of patients, regardless of HIV stage, and



is often reported to be concurrent with HIV-associated dementia, diagnosed in 8% to 22% of cases. Substance use disorders are diagnosed in 11% to 36% of inpatients with AIDS and up to 63% in HIV-positive patients who do not have AIDS. Only one study explicitly addressed bipolar spectrum disorders, including primary bipolar disorder and HIV-associated mania, which occurred in 11% of patients.¹⁰

Differential diagnosis is paramount in evaluating psychiatric disorders and symptoms in medical inpatients with HIV disease or AIDS, especially when investigating for medical and neuropsychiatric etiologic factors related to HIV illness and its treatment. Table 19.2 lists the major differential diagnostic considerations.

Of patients with HIV infection, 60% to 70% have one or more psychiatric disorders before contracting HIV illness.¹⁰,¹¹ Medical hospitalization can serve as a triggering stressor for relapse of primary psychiatric disorders once HIV infection is diagnosed. Thus, in assessing the hospitalized patient, it is important to query for personal and family psychiatric history in order to assess for vulnerability to relapse. However, even in the presence of a prior psychiatric history, it is most important to rule out potentially exacerbating, if not etiologic, medical factors. As discussed in Chapter 12, HIV-associated neurocognitive disorders are associated with a range of cognitive and behavioral symptoms, including apathy, depression, sleep disturbances, mania, and psychosis. CNS opportunistic illnesses and cancers can also present with a wide range of behavioral symptoms, most often in the context of delirium, as a result of both focal and generalized neuropathologic processes. Table 19.3 lists the major CNS opportunistic infections, their symptom presentations, and their diagnostic workup.

Substance intoxication and withdrawal are also common in the medical inpatient setting (see Chapter 14). Most notable in this context is that HIV-infected substance users have high rates of preexisting comorbid psychopathology that may be exacerbated by ongoing substance use. Further, these individuals often abuse multiple substances concurrently, which compounds the complexity of assessing behavioral symptoms and presents the challenge of treating mixed withdrawal states.

HCV infection, independent of HIV coinfection and interferon/ribavirin therapy, is associated with multiple neuropsychiatric complaints, most frequently fatigue, depression, and cognitive dysfunction. The pattern of cognitive impairment is similar to that in HIV disease, with impairment in attention, concentration, psychomotor processing speed, verbal memory, and executive dysfunction. Patients with end-stage liver disease and cirrhosis experience superimposed delirium (hepatic encephalopathy). Combination pegylated interferon alfa-2a
treatment for HCV infection has been extensively documented to cause neuropsychiatric side effects, including depression, suicidal ideation, anxiety, sleep disturbance, fatigue, mania, psychosis, confusion, and cognitive dysfunction.¹²