Diagnostic features of the cycloid psychoses in a first psychotic episode sample.

Introduction: The cycloid psychoses have not been included in the modern classifications-what makes scientific research difficult. The aim of the present study is to investigate the presence and specific characteristics of the cycloid psychoses in a broad sample of first psychotic episodes.

Methods: Seventy patients diagnosed with one-year first schizophrenia episode, schizophreniform disorder, or schizoaffective disorder were studied (mean age, 27.9 years old; SD±6.34). The detection of the possible cases of cycloid psychosis was done according to the Perris and Brockington operational criteria. Two groups of "cycloid" (n=11) and "non cycloid" (n=59) patients were compared according to demographic and clinical variables, and possible diagnostic variables were evaluated by the ROC curves.

Results: Significant differences were found between cycloid and non cycloid groups for a number of clinical variables: prodromic symptoms (p<0.001), PANSS total score (p=0.003), PANSS-P (p=0.009), PANSS-GP (p=0.001), total score for mania by EVMAC (p=0.001), and CDSS for depression (p=0.004). ROC curves were significant for PANSS-GP (AUC=0.791, p=0.002), EVMAC (AUC=0.938, p=0.001), and CDSS (AUC=0.770, p=0.005). A sensitivity/specificity study demonstrated a negative predictive value for PANSS-GP (93.88%), EVMAC (96.30%), and CDSS (93.88%).

Conclusions: According to these results, cycloid psychoses might represent differentiated and well-defined clinical entity.