Depressed or delirious? Overdiagnosis of depression in medically hospitalized patients

Misdiagnosis of depression and delirium by non-psychiatric clinicians is common. Depression over-diagnosis can cause stigmatization of normal emotional reactions and delays in addressing delirium. We performed a multisite retrospective chart review to examine diagnostic agreement between non-psychiatric services and the consultation-liaison psychiatry (CLP) service.

We reviewed inpatient depression and delirium referrals across two Cleveland Clinic sites. Agreement between referral reason and CLP service diagnosis was assessed. We fit multivariable logistic regression models for the dependent variables of depression overdiagnosis and delirium masquerading as depression, with independent variables that included the primary team discipline and demographic and clinical variables.

Diagnostic agreement for delirium, strict depression diagnosis, and broad depression diagnosis were 88 %, 67 %, and 80 %, respectively. Of patients referred for depression who did not receive a CL psychiatry diagnosis of depression, 49 % were diagnosed with adjustment disorder, 18 % with anxiety/OCD, 16 % with delirium, and 4 % with neurocognitive disorders. Older age and prior psychiatric diagnoses decreased the likelihood of depression overdiagnosis. Psychotropic medication use increased the likelihood of delirium misdiagnosed as depression.

Primary services overidentify depression and more accurately identify delirium. However, given that most alternative diagnoses were anxiety disorders or adjustment disorders, primary services seem adept at identifying psychological distress, which may be related to destigmatization and education efforts by psychiatrists. Primary services recognize prior psychiatric diagnoses as a depression risk factor and demonstrate awareness of geriatric presentations. However, prior psychotropic use may introduce bias. Further research, including direct knowledge and attitude assessments, is needed.