The purpose of this study is to assess the effectiveness of systematic screening for depression in high-risk patient participants in everyday clinical practice. Systematic screening for depression in high-risk patients is recommended to be included as a usual practice but its effectiveness in this context remains controversial. In this study, 35 primary care physicians (PCPs) in Spain were assigned to intervention (receive one day training in depression screening guidelines and use guidelines for six months) and 34 PCPs were assigned to a control group (manage depression in the usual way for six months). There were a total of 525 patient participants with MDD.

Inclusion Criteria:

• PCP Participants: PCPs informed of the study design and who agreed to be randomized to the intervention or control group
• Patient Participants: Aged 18 years or older who provide a written consent for the collection and use of their clinical data

Exclusion Criteria:

• PCP Participants: If they already follow the recommendations on screening or were planning to do so. If they will be absent from their practice for a significant period during the study, or if they do not usually manage depression
• PCP Participants: Those who were not able to understand the aims of the study

Primary Care Physicians are given the intervention of education to utilize on screened and consented patient participants under the PCP care.