Diagnostic and referral hierarchical model of common mental disorders in primary care centers. The PsicAP clinical trial approach

Common mental disorders are the most prevalent in primary care (PC) centres in Spain. Unfortunately, there is a high percentage of undetected cases, due to underdiagnosis or overdiagnosis. An incorrect identification of these disorders leads to inaccurate referrals; 39% receive no treatment and only one in three patients treated follow a minimally evidence-based treatment. In the PsicAP clinical trial, the psychometric properties of the Patient Health Questionnaire (PHQ), its different modules of anxiety (GAD-7), depression (PHQ-9) and panic disorder (PHQ-PD), and an ultra-brief version derived from the PHQ for anxiety and depression (PHQ-4) have been analysed. A diagnostic and referral hierarchical model of common mental disorders is proposed based on the validation of these instruments among patients attending Spanish PC centres.