A quarter of people with HIV in the UK have a depressive disorder, according to an ongoing study presented by Dr Fiona Lampe to the British HIV Association conference in Birmingham yesterday. The study found strong links between depressive symptoms and unemployment, poverty and not having much social support.
Those with depression were more likely to have problems with adherence and less likely to have an undetectable viral load than other people in the cohort.
This is not the first study to show that depression and other mental health issues can be linked to poor adherence and to poorer clinical outcomes, but research has generally been carried out in the United States, where the social characteristics of people with HIV are different to those in the United Kingdom.
In order to address the lack of relevant data, researchers included questions on depression in the self-completed questionnaires given to people participating in the ASTRA (Antiretrovirals, Sexual Transmission Risk and Attitudes) cohort.
The 2175 participants are attending HIV-outpatient services at one of six UK clinics (Royal Free, London; Mortimer Market, London; Homerton, London; North Manchester; Brighton and Eastbourne). The profile of those taking part does not entirely match that of the wider UK epidemic – 73.4% are gay or bisexual men; 10.1% are heterosexual men and 16.4% are women. The average age is 44 and the vast majority are taking antiretroviral therapy.
The data presented here are cross-sectional – in other words, they come from a single point in time. While the data show strong associations between depression and social factors, they cannot prove causality.
Questions about depressive symptoms came from a validated tool known as PHQ-9, which asks the respondent whether he or she has experienced nine different symptoms over the past two weeks. The respondent should specify how often they have been bothered by these problems.
Based on these answers, 26.6% of respondents had a depressive disorder. Moreover, for 19.1% of respondents this was a major depressive disorder.
Using a different classification, the depression severity score, 20.6% had mild depression; 20.4% had moderate depression and 6.6% had severe depression.
As a point of comparison, in the English general population 7% have either moderate or severe depression. However an audience member pointed out that a better comparison may be with other people who have another chronic medical condition, such as diabetes.
Rates of depression did not vary according to gender, sexuality, ethnicity or country of birth.
On the other hand, there were striking associations with socioeconomic factors. These were all found to be statistically significant in a multivariable model.
Whereas 15.3% of employed people had symptoms, 43.4% of those who were unemployed and 52.8% of those unable to work due to sickness or disability had symptoms.
Among individuals who said they always had enough money to cover their basic needs, 13.3% had depressive symptoms, but among those who said they only sometimes had enough money, 43.2% had symptoms. In participants who could never cover their basic needs, 53.0% had depression.
In terms of education, 18.8% of people who had attended university and 31.7% of those who had not described depressive symptoms.
A number of questions assessed social support, and there was a clear relationship between degrees of social support and depressive symptoms.
|1: High social support||8.9%|
|5: Low social support||66.1%|
Moreover, the longer someone had been diagnosed with HIV, the more likely they were to be depressed.
Adherence and virological outcome
The researchers also found an association between depressive symptoms and self-reported poor adherence to antiretroviral therapy. Among those saying that they had missed no drug doses over the past two weeks, 24.1% had depression. Among those who said they had missed two doses, 34.3% had depressive symptoms. In those who missed three or more doses, 41.7% were depressed.
Amongst those who had been on treatment for more than six months, people who described depressive symptoms were less likely to have an undetectable viral load. For those without depression, 7.5% had detectable virus, while in those who had depression, the figure was 16.3%. Increasing depression severity scores were associated with higher rates of detectable virus.
As the association between depression and poor virological outcomes could simply be due to the association between depression and poor adherence, further analyses were conducted to clarify this. In statistical terms, having depression remained a risk factor for having detectable HIV, even after adjusting for non-adherence.
However it is important to note that adherence was measured by self-report and concerned only recent adherence, in the past two weeks.
The researchers suspect that screening for depressive symptoms may, in itself, give clinicians valuable information about adherence, beyond that revealed by asking patients about missed doses.