Research Shows Undiagnosed Depression In TB Patients Threatens Control Of The Disease
Each year on 24 March, the world commemorates World TB (Tuberculosis) Day. This date coincides with the day in 1882 when Robert Koch announced his discovery of the Mycobacterium Tuberculosis, the germ that causes TB. This infectious disease is transmitted through airborne droplets when an infected person coughs, sings, shouts, or sneezes. TB primarily affects the lungs (i.e., pulmonary TB), but other organs in the body such as the pleura, lymph nodes, abdomen, genitourinary tract, skin, joints and bones, or meninges (i.e., extra-pulmonary TB) can also be affected. TB can be cured; effective anti-TB drugs have been available for almost eight decades. Despite this, TB continues to wreak havoc across the world and in South Africa. According to a report released by the World Health Organisation (WHO), an estimated 304 000 new TB cases were reported in South Africa in 2021 and 56 000 people succumbed to the disease in the same year
A world without TB
In 2014, the sixty-seventh World Health Assembly endorsed a global strategy and targets for TB prevention, care, and control. The strategy envisions a world without TB, aiming to end the epidemic by 2035. By this target date, a reduction in TB deaths of 95% and new infections of 90% – compared to the respective levels in 2015 – are anticipated. Further to this, the United Nations’ Stop TB Partnership was mandated to drive activities to end the global TB epidemic. In 2015, the partnership launched the 90-(90)-90 targets; to reach at least 90% of people with TB and place them on appropriate treatment, including at least 90% of vulnerable populations such as people living with HIV, and to ensure that at least 90% of people with TB are successfully treated. Despite commendable progress, persisting high TB infection and death rates are adversely affecting global and national efforts to end the TB epidemic. With a treatment success rate of only 78% in 2020, South Africa is sorely challenged to attain the global target of 95%.
TB with mental health illness
One of the challenges confronting TB control is the frequent comorbidity of TB with mental health illness. There is compelling evidence linking TB to common mental health problems such as depression, anxiety, and alcohol misuse. Research indicates that TB patients can experience mental health problems at any time during the course of their TB treatment. Undiagnosed mental illness among TB patients may result in poor health-seeking behaviour and non-adherence to treatment, subpar quality of life, and negative treatment outcomes. The WHO’s Global End TB Strategy thus recommends integrated patient-centred TB care. This implies that TB care should be provided in close collaboration with other primary health-care (PHC) programmes such as mental health. However, in many countries – South Africa included – efforts to integrate mental health and TB care are confronted by challenges such as limited capacity, nonrecognition of mental health as a problem, insufficient resources, and TB-related social stigma. Consequently, mental health conditions in TB patients are often un-/under-/mis-diagnosed.
Taking depression as a compelling example, a scoping review reported the prevalence of depression as high as 84% among people with TB in studies conducted internationally. However, little is known about the prevalence of depression among TB patients in South Africa. Using a nine-item Patient Health Questionnaire, we assessed probable depression among a sample of TB patients attending PHC facilities in the Free State. We found that almost half (46,1%) of the 208 patients interviewed had probable depression, with 22,6%, 18,8%, and 4,8% having mild, moderate, and severe symptoms, respectively. Probable depression was almost four times more likely among patients diagnosed with extra-pulmonary TB compared to pulmonary TB patients. HIV-infected TB patients undergoing antiretroviral therapy were more than twice as likely to experience symptoms of depression compared to their counterparts who were not undergoing such therapy. This could possibly be attributed to non-adherence to antiretroviral therapy. Studies elsewhere have established a significant association between depression and ART non-adherence. We further found that the longer patients were retained on TB treatment, the less likely they were to display symptoms of depression.
Important to monitor TB patients for depression
Based on these findings, it is important to monitor TB patients for symptoms of depression – particularly those with comorbid HIV – in PHC settings. At the same time, ensuring that patients stay on treatment by providing adequate support for treatment adherence may help to mitigate depression during TB treatment.
The theme for this year’s World TB Day is ‘Yes! We can end TB’. It is a call for concerted multi-sectoral collaboration between governments, civil society, communities, academia and technical partners, international aid and scientific organisations, the private sector, and disease control programmes in the country to eliminate the TB epidemic. To this end, TB patients attending PHC facilities in South Africa need to be routinely screened for mental health illness. Given the critical shortage of mental health specialists, screening for mental illnesses could be undertaken by trained and well-supervised non-specialist healthcare cadres such as community health workers.