Differential-diagnostic confusion and non-specificity of affective symptoms and anxiety: An empirical study of first-admission patients

In everyday clinical work, psychiatrists encounter patients who present with symptoms spanning several diagnostic categories, e.g., showing signs of a psychosis, depression, and anxiety. This raises the critical question of which symptoms hold precedence over other and, by extension, which diagnosis is the right diagnosis. ICD-10 and DSM-5 do not provide unambiguous answers to this question and therefore psychiatry remains exposed to diagnostic disagreement with consequences for treatment and research. We explored symptom distribution in a sample of 98 first-admission psychiatric patients. We extracted and categorized singular symptoms into symptom domains: anxiety, mania, delusions, hallucinations, first-rank symptoms, and negative symptoms. Most symptoms were seen in most disorders. We found symptoms of depression and anxiety in almost all patients. Thus, just counting symptoms do not seem to be a valid way to make diagnoses. We elaborately discuss these issues in the context of the differential-diagnosis between schizophrenia and depression. Finally, we suggest that a combination of a criteria- and Gestalt-based approach to diagnosing mental disorders may contribute to counteract some of the current differential-diagnostic confusion.