John: Hello, I'm John Hilton, senior editor at Cochrane. In many settings where access to health care is limited, governments are looking for effective and efficient ways to deliver routine health services. To help with this, the Cochrane EPOC Group is producing a series of reviews on task shifting the delivery of care to healthcare providers with lower levels of training. In August 2021, they published an update to the 2013 Cochrane Review of the effects of engaging community‐based primary-level workers in helping people with mental health disorders or distress in low and middle-income countries. We asked one of the main authors, Weng Yee Chin from the University of Hong Kong, to tell us about their findings.

Weng: Many people with mental health disorders in low- and middle-income countries do not receive the care they need because of challenges in accessing specialist mental health services and stigma. One potential solution is to offer services delivered by primary-level workers such as generalist doctors and nurses, lay or community health workers, community volunteers and non-medical members of the community, such as teachers. These primary‐level workers can play key roles in addressing gaps in mental health service delivery and our review brings the relevant evidence together into one place.
It's a large review, with 95 randomized trials from 30 lower- and middle-income countries. The studies were set in rural, urban and refugee camp settings; and involved non-medical professionals such as teachers, and non-specialist health professionals such generalist doctors, lay health workers and nurses delivering mental health treatments for a wide range of mental health issues. These included depression, anxiety, post-traumatic stress disorder, postnatal depression and alcohol or substance use. 
Overall, we found that when primary-level workers are given appropriate mental health training, they may be able to help people living with different mental health issues when compared to people receiving no care or receiving care from primary-level workers with minimal or no extra training in mental healthcare. However, the evidence was of very low certainty for many of the findings, and very few studies assessed outcomes more than 6 months after the intervention, reported on the effects of this task shifting on the use of health care or adverse events, or provided data needed for robust analyses of cost-effectiveness.
Working through the different types of participants in the research, we found that care from primary-level workers may increase the number of adults who recover from depression or anxiety and improve quality of life. This care may also reduce referral rates to mental health specialists. 
For women with perinatal depression, we found that care delivered by lay health workers probably slightly reduces symptoms of depression, may increase recovery, and slightly improves people's day-to-day functioning.
In adults with alcohol or substance use problems, we found that care delivered by primary-level workers probably slightly reduces the risk of harmful or hazardous drinking but the effect on recovery from harmful or hazardous alcohol use and whether this care improves day-to-day functioning or quality of life are uncertain.
For adults with severe mental disorders such as schizophrenia, we found that care delivered by lay health worker may have little to no effect on caregiver burden when compared to care from mental health specialists and that treatments from primary health professionals alone or in collaboration with mental health specialists may improve day-to-day functioning for this group of people, when compared to treatments by mental health specialists alone. 
Finally, turning to people in humanitarian settings with post-traumatic stress or depression and anxiety, we found that care from lay health workers, teachers and social workers had little to no effect on depressive or post-traumatic symptoms or on day-to-day functioning in children but the interventions were not found to be harmful or to have any adverse effects. For adults, we found that care from primary-level workers probably slightly improves quality of life, may slightly reduce symptoms of depression and may also help reduce the number of people with post-traumatic stress symptoms.

John: Thank you Weng. If you would like to access the full version of the review, it's available free online. Just go to Cochrane Library dot com and search 'primary-level worker and mental health' to see the link.