Title: Screening for common mental disorders in primary care in low and middle income countries
Description: The goal of this dissertation is to examine the utility of screening for common mental disorders in primary care in low and middle income countries. Screening for common mental disorders in primary care is often considered as an important step in addressing the mental health treatment gap in low and middle income countries. Nevertheless, there is insufficient evidence to support routine mental health screening in primary care in these countries. Even in high income countries, there is a lack of consensus on the effectiveness of routine mental health screening in primary care, especially screening for depression. Challenges to screening include the high rates of false positive diagnosis, poor evidence on outcomes for people identified by screening, and potential harms due to screening. The specific aims of this dissertation are to: 1) synthesize evidence from low and middle income countries on the current practices of screening for common mental disorders in primary care and the use of screening instruments; 2) understand the significance of a positive screen for common mental disorder in primary care, specifically the distribution and the stability of ICD-10 diagnosis for screened positive patients, their clinical course over a period of one year, and the factors associated with the clinical course; 3) examine the factors associated with antidepressant prescriptions for patients screened positive for common mental disorders in primary care and evaluate the appropriateness of antidepressant prescriptions following screening.

Based on our review of literature, evidence to support routine screening for common mental disorders in primary care in low and middle-income countries is inadequate. We highlight concerns about the fidelity with which screening is implemented, especially the flawed use of screening instruments. Introducing depression screening and physician notification in these settings seldom results in improved access to care or appropriate care. The majority of patients identified by screening in primary care have contextual, and probably non-pathological psychological distress (see page iii, for definition of key terms) which is often temporary and self-limiting. Patients with persistent distress symptoms identified by repeated screening, and those with moderate to severe depression may benefit from screening in the presence of evidence based stepped care interventions that are easily accessible and acceptable. Although, the long term effects of these interventions and the sustainability of such primary care based programs in low and middle income countries are uncertain.

Our analysis of data from a cluster randomized control trial in India confirmed that a significant proportion of patients screened positive for common mental disorders in primary care has psychological distress that is temporary and self-limiting. However, a smaller, albeit important share of patients also experienced psychological distress that persisted throughout one-year follow-up. Persistent distress was predicted by psychosocial and economic disadvantage. Thus, psychosocial support systems and structural interventions have a larger role to play in addressing psychological distress. We found poor diagnostic stability for ICD-10 based diagnoses, and the most stable and prevalent diagnosis was mixed anxiety and depressive disorder. Further, we found that antidepressants are widely prescribed following screening especially for women and older adults. While many patients with moderate to severe depression could benefit from antidepressants, it is problematic that a significant proportion of patients with less severe disorders also received anti-depressant prescription despite the availability of non-pharmacological treatment options.

In summary, there is a lack of empirical evidence to support routine screening for common mental disorders in primary care in low and middle income countries as an effective strategy to identify those in need of treatment; instead screening could lead to over diagnosis and inappropriate antidepressant prescriptions. To address psychological distress in primary care and the unmet need for treatment in low and middle income countries, there is an urgent need to focus on locally driven and culturally relevant approaches to case finding and intervention.