Drill-locate-drill algorithm for diagnostic reasoning in psychiatry

This paper introduces a top-down algorithm for diagnosing psychiatric illnesses. It is based on the conceptualisation of diagnostic categories, diagnosis, and symptoms as a hierarchical model. The algorithm assumes that there exist a few close-ended clinical questions that can be used during clinical interview to rule in and rule out diagnostic categories, diagnoses and their symptoms. Compared to a more exhaustive bottom-up and recursive algorithm, which the authors have previously introduced, this algorithm has the advantage of being easy to implement requiring a less extensive knowledgebase. It is expected the algorithm will be used as a useful screening tool that increases the detection of psychiatric disorders, which are common but unfortunately currently under-diagnosed.