26th International AIDS Conference 2026 in Rio de Janeiro
Article by Marlon Gattiker

The study analysed 624 people with HIV aged 50 and over, all of whom were receiving effective treatment (viral load below 200 copies/ml). The mean age was 62 years. Cognitive function was assessed using the widely used MoCA (Montreal Cognitive Assessment) test, whilst depression was assessed using the PHQ-9 questionnaire.

The key finding: over half of the participants (50.5 per cent) scored 23 points or lower on the MoCA – an indication of impaired cognitive function. This is consistent with earlier Brazilian studies, which had found a prevalence of around 44–53 per cent.

Several factors were found to be statistically closely linked to lower cognitive performance:

• Older age – performance declined further with each age category.
• Social vulnerability: People of colour (in Brazil: Preto/Pardo) and those with lower levels of education performed significantly worse – those without any schooling or with fewer than 8 years’ schooling were the most severely affected.
• Mental health and HIV progression: Higher depression scores (PHQ-9) and a lower historical CD4 nadir – i.e. more severe immune deficiency at an earlier stage – were also associated with poorer outcomes.
• Medication history: Longer cumulative use of efavirenz (an older HIV drug known for its neuropsychiatric side effects) was associated with poorer performance. The newer drug dolutegravir did not show this association.

Corção emphasises that cognitive health in older people living with HIV is not determined by the virus alone, but by an interplay of biological history, mental health and social disadvantage. Her recommendation is that routine screening for cognitive impairment and depression should become an integral part of HIV care for older people, in order to identify those at risk at an early stage and provide them with targeted support.

The MoCA test is a screening tool, not a diagnostic test – a low score therefore does not automatically indicate a diagnosis of dementia. Furthermore, people with a history of severe psychiatric or neurological conditions were excluded – precisely those groups in which impairments frequently occur in practice.

In Switzerland, too, a growing number of people are living with HIV long-term, having undergone previous treatments, whilst mental health and social isolation in old age are key issues. The study provides a strong argument for systematically incorporating cognitive and mental health into HIV care.

Source: Corção, P. “Biological and Psychosocial Factors in Cognitive Decline Among Older Adults with HIV.” Presented at the 26th International AIDS Conference (AIDS 2026), Rio de Janeiro, 26–31 July 2026. Priscila Corção is a neuropsychologist at the Instituto Nacional de Infectologia Evandro Chagas (INI), Fundação Oswaldo Cruz (Fiocruz), Brazil. Data source: ELEA-Brasil study (“Estudo Longitudinal do Envelhecimento e AIDS”).