People with untreated mental illness or substance abuse, or both together, start HIV treatment later than people without mental illness or substance abuse, according to a study published in the March 1 issue of AIDS Patient Care and STDs. People who are receiving drug treatment for a mental illness, however, do not delay starting HIV treatment.

Delaying antiretroviral treatment until CD4 counts drop to 200 or lower has been found to significantly increase the risk of illness and death, and HIV treatment guidelines were recently revised to encourage all people with CD4 counts less than 350 to start antiretroviral therapy as a result of this.

Given that rates of mental illness and substance abuse are more common in people living with HIV, and that these conditions have been found to interfere with adherence to HIV treatment, Mary Tegger, P.A.-C, MPH, and her colleagues from the University of Washington in Seattle set out to determine whether these conditions may also delay the start of antiretroviral therapy.

The team examined the medical records of all HIV-positive patients receiving primary care at the university’s Harborview Medical Center HIV Clinic during 2004. Patients who had an initial visit to the clinic on or after January 1, 2000, and who had never taken antiretroviral medication were included in the study. Tegger’s team judged that a person was an appropriate candidate for HIV treatment when their CD4 count fell below 350.

Of the 1,744 patients included in the study, 63 percent were found to have a mental illness, 45 percent had a substance use disorder and 38 percent had both. Alcohol was the most commonly abused substance, followed by cocaine and amphetamine. Depression and anxiety were the most commonly diagnosed mental illnesses.

Tegger’s team found that people with an untreated mental illness were 60 percent less likely than people without a mental illness to start antiretrovirals within nine months of having their CD4 count fall below 350. People with a substance abuse disorder were about half as likely to start antiretrovirals. People who received drug treatment for their depression and anxiety, however, were as likely as people without a mental illness to start antiretrovirals per treatment guidelines.

Tegger’s team theorizes that there are multiple reasons for the delay in antiretroviral treatment observed in people with mental illness and substance abuse disorders. The team proposes that such individuals are less willing, on average, to comply with treatment recommendations, such as starting antiretroviral treatment. The team also proposes that many health care providers are reluctant to start antiretroviral treatment in people who are perceived to be less able to be adherent to antiretrovirals.

Given the very high rates of mental illness, substance abuse, and particularly the two combined, observed in this study, Tegger’s team predicts that health care providers across the United States are going to have to contend with these issues. The team also points out that since in this study people being treated for mental illness did not delay antiretroviral therapy, effective treatment for those with mental illnesses and substance abuse disorders may shorten or eliminate the delay in HIV treatment among these populations.