Use of haloperidol as a trial of treatment in diagnosing major depressive disorder with subclinical psychotic features.

Patients may present with subclinical psychotic features not meeting established diagnostic thresholds for psychosis. Here, we describe our experience of using Haloperidol as a trial of treatment to clarify the diagnostic uncertainty in a patient presenting with major depressive disorder with subclinical psychotic features. Our case highlights the importance of having a high index of suspicion for subclinical psychosis in patients presenting with treatment-resistant affective symptoms despite the use of multiple classes of antidepressant and/or anti-anxiety medications, as well as the need to undertake comprehensive assessments to clarify the differential diagnosis. Our experience may support trialling treatment with antipsychotics if a diagnosis of subclinical psychotic phenomena is being considered.