Mood Symptoms in Stabilized Patients with Schizophrenia: A Bipolar Type with Predominant Psychotic Features?

BACKGROUND: Schizophrenia (SZ) and bipolar disorder (BD) are traditionally distinguished on the basis of progressive deterioration and long-term outcome, but a more dimensional approach is warranted. There are limited data on the occurrence of manic symptoms in patients with schizophrenia. The aim of the current study was to search for patterns in the clinical symptomatology, which may suggest the presence of one or several mood disorders under the label of schizophrenia.

SUBJECTS AND METHODS: Hundred-seventy-five patients diagnosed with schizophrenia according to DSM-5 were included in the study. The psychometric assessment included the Positive and Negative Syndrome Scale, Young Mania Rating Scale, The Montgomery-Åsberg Depression Rating Scale and the Calgary Depression Scale. The statistical analysis included MANOVA, Pearson Correlation coefficient and principal components analysis.

RESULTS: Significant subthreshold manic symptoms were present in 25.14% of patients. Mood symptoms correlated with positive symptoms. The PCA revealed a complex structure with 15 factors (one positive, negative, somatic, anxiety, neurocognitive, disorganization and manic, five depressive and three psychomotor/excitement/hostility/violence).

CONCLUSION: Psychotic mood disorders are often phenotypically indistinguishable from schizophrenia, so it is likely that psychotic affective patients have been misdiagnosed with schizophrenia. The current study suggests that there seem to be patients with mania misdiagnosed as 'schizophrenics' because of the presence of psychotic features, a condition better described as 'schizophreniform bipolar disorder'.