CONTEXT AND OBJECTIVE: Adherence to antiretroviral treatment (ART) is not a stable condition, but is dynamic, like mental conditions. The aim of this study was to examine whether non-adherence to ART is related to demographic and immunological variables, substance use and presence of depressive symptoms. DESIGN AND SETTING: This was a cross-sectional prevalence study carried out at a public AIDS treatment center in the city of São Paulo, Brazil, between July 2006 and January 2007. METHODS: 438 patients on regular ART schedules with recent laboratory tests answered a demographic questionnaire, questions about substance use, the Hamilton Depression Rating Scale (HDRS) and the Simplified Medication Adherence Questionnaire (SMAQ). RESULTS:The prevalence of non-adherence over the past three months (a pattern of treatment interruption) was 46.3%, and 27.2% also reported this in the past week (a pattern of missed doses). ART interruption was significantly related to older age, lower CD4+ cell count and homosexual/bisexual transmission. The pattern of missed doses was significantly related to younger age, higher HDRS scores and higher viral load of RNA HIV. CONCLUSION: ART interruption may reflect recall errors and changes to the Brazilian demographic characteristics of HIV infection. The missed doses may reflect lifestyle characteristics of younger individuals. Attendance for HIV-positive individuals, particularly younger patients, should involve interventions and counseling in relation to the presence of depressive symptoms.RESUMO CONTEXTO E OBJETIVO: Adesão ao tratamento antirretroviral (TARV) não é uma condição estável, mas dinâmica, como os transtornos mentais. O objetivo deste estudo foi verificar se a não adesão ao TARV relaciona-se às variáveis demográficas e imunológicas, ao uso de substâncias e à presença de sintomas depressivos.

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