LAUSR

Empirically supported psychological treatments – spanning interpersonal, cognitive and behavioural therapies – are recommended as first-line interventions to address the significant burden of depression, anxiety and stress-related disorders worldwide. Nevertheless, they remain inaccessible for the wide majority of the world’s population, both in lowand middleincome countries (LMICs), where less than 5% of people with major depressive disorder receive minimally adequate treatment, and in high-income countries (HICs), where the corresponding figure reaches only 20%. This massive treatment gap for such effective treatments is unprecedented in medicine and, as the experience of HICs shows, is not simply a challenge which can be addressed by more mental health care providers. Here we summarize a range of potential strategies through which these treatments might be scaled up to achieve their full potential and reduce the global burden of common mental disorders. Three major barriers prevent delivery of psychological treatments: the lack of skilled providers, limited access, and low demand for mental health care. Each is an obstacle in most countries, but all have viable, evidence-based solutions. If we assume that a “skilled” provider is a health care professional who has been trained in one of the mental health disciplines (social work, psychology or psychiatry), then there is no chance of overcoming the first barrier. There are large gaps between the required and actual numbers of mental health professionals in all countries. Furthermore, the methods typically used to train these specialized persons are expensive, time-intensive and requiring of another, even more experienced specialist to conduct regular supervision for an extended period of time. An effective strategy to address this barrier is “task sharing” or training non-specialist providers – i.e., individuals with no formal training or background in mental health care – to deliver brief, low-intensity psychological treatments. The concept of non-specialist providers originated from para-professional movements in the US and UK. They include nurse practitioners, community health workers, teachers and peers, and are selected because of their availability, low cost, access to and close ties with the population they serve. Not only can nonspecialist providers in LMICs be trained to deliver treatments (and as effectively as specialists in HICs), but recent evaluations demonstrate that they can ensure high quality of therapy through peer-led supervision. This, in turn, addresses the bottleneck of the need for supervision provided by mental health specialists. Recent evidence also makes clear that utilizing a core set of common treatment “elements” (such as behavioural activation, exposure, problem solving and communication skills) can reduce the complexity of needing to learn diverse psychological treatment packages for specific clinical phenotypes (such as depressive, anxiety and stress-related disorders). For example, the COBRA trial in the UK demonstrated that nonspecialist junior mental health workers with no previous professional training in mental health services successfully delivered a treatment package that focused on the core element of behavioural activation. Results showed equivalent effectiveness in reducing depressive symptom severity as specialists delivering longer courses of cognitive behavioural therapy. Similarly, in India, lay counsellors trained over 3 months to deliver a culturally adapted version of behavioural activation attained improved remission rates and sustained outcomes in primary care attenders with moderately severe to severe depression. The second barrier is limited access to psychological treatments. In most countries, psychological treatments are accessible only to a minority of individuals who can afford private treatment or who are supported by generous insurance programs. Furthermore, these provider-centered treatments are typically delivered face-to-face, in urban specialist facilities, and at a time that is most suitable for the provider. In contrast, evidence-based solutions involve the delivery of psychological treatments in settings and at times that are convenient to the patient (for example, at home and during the weekend). In addition, the use of telemedicine and other digital platforms can facilitate this flexibility as well as guided self-care. Delivery of a treatment through a digital platform may be as effective as in-person treatment, but preferred by the recipient and with better sustained outcomes. Moreover, recent evaluations have demonstrated that therapists can be efficiently trained through digital platforms. In all contexts, these feasible and cost-effective solutions may be particularly beneficial for individuals with limited financial, social or physical capacity to travel to health facilities, such as mothers with infants, individuals with physical disabilities, or people who are homebound for various reasons, including due the impact of mental disorders. Third, there is a low demand for psychological interventions, particularly from lower social classes and ethnic minorities, and treatment retention of most psychological treatments is less than 50% in most patient populations. The solutions to these problems reflect lessons learned from a community engagement model used for psychosis. There is growing evidence of the benefits of: engaging a “grassroots” perspective when developing and designing mental health services; avoiding biomedical labels and using patients’ own explanatory models; targeting social determinants concurrently with psychological symptoms; and engaging the individuals’ relationships and resources, including their partner and community at large. Furthermore, a common elements approach is also likely to be