Inconsistent use of antiretroviral therapy is the main
explanation for the higher viral loads observed in HIV-positive patients who
are depressed or who use stimulant drugs, US investigators report in the
February 1st edition of the Journal of Acquired Immune Deficiency Syndromes.
“Inconsistent patterns of ART [antiretroviral therapy]
utilization account for the effects of depression and stimulant use on higher
HIV viral load,” comment the investigators.
The research team, lead by Dr Adam Carrico of the Center for
AIDS Prevention Studies at the University of California, San Francisco, believe
their findings have implications for the use of HIV therapy in prevention.
They write: “Adjuvant mental health and substance abuse
treatment will be needed to promote sustained ART utilization, achieve viral
suppression, and address HIV risk behavior among individuals with psychiatric
Mental health screening and monitoring of drug use should
therefore be incorporated into routine HIV care.
Faster HIV disease progression has been observed among
patients taking antiretroviral therapy who are depressed or who use stimulant
drugs such as cocaine, crack, or methamphetamine.
Researchers from Mental Health Healthy Living Project wished
to see if this was because of inconsistent use of HIV therapy by patients who
had symptoms of depression or who used stimulant drugs.
The investigators therefore monitored the CD4 cell count and viral load of 603
patients over a 25-month period.
Information was gathered on the patients’ use of HIV
treatment (continuous; intermittent; discontinued), and participants completed
questionnaires to determine if they had depression and to assess their use of
The patients’ mean age was 41 years, 80% were men, and 70%
identified as gay or bisexual. The majority (54%) were African American.
On entry to the study, 94% of patients were taking
antiretroviral therapy, but only 33% had an undetectable viral load. The
average level of adherence reported over the 25 months of the study was 88%. A
fifth of patients reported using stimulants on a weekly basis, 5% said that
they used heroin, and 12% had a history of injecting drug use in the previous
Depression at baseline was associated with a 39% increase in
the risk of interrupting HIV therapy, and weekly stimulant use increased the
odds of treatment discontinuation 2.5 fold (51% vs. 25%).
The investigators’ first set of analysis showed that
depression was associated with a 50% higher viral load during follow-up (p <
0.01). However, the association between depressive symptoms and viral load
ceased to be significant when the investigators took into account the higher
rates of treatment interruption or discontinuation among patients with mental
“Those with elevated depressive symptom severity may be more
likely to discontinue ART regimens due to the pervasive sense of hopelessness
and pessimism that are common features of depression,” comment the authors.
Weekly stimulant use predicted a 137% higher viral load (p
< 0.05). However, after taking into account higher rates of discontinuation
among individuals who regularly used this type of drug, the association between
higher viral load and stimulant use ceased to be significant.
“Intermittent ART utilization may be more common among
stimulant users because stochastic periods of binge are more common in this
population,” suggest the investigators, “individuals may be more likely to stop
taking ART regimens during periods of binge stimulant use but then re-initiate ART
during periods of less frequent stimulant use or abstinence.”
The investigators therefore conclude that inconsistent use
of HIV therapy is the main reason for the higher viral loads seen in patients
with depression as well as for those who use stimulant drugs. However, they do
not rule out possible biological factors, for example immune stimulation, or
behavioural factors such as poor sleep and self-care.