Is it possible to combine different psychotic symptom scales in bipolar disorder?

It has been suggested that data on positive and negative psychotic symptoms in patients with schizophrenia as assessed using different scales may be combined. For the first time, we assessed correlations between the positive syndrome subscale of the Positive and Negative Syndrome Scale (PANSS-P) and the Scale for the Assessment of Positive Symptoms (SAPS), and between the negative syndrome subscale of the Positive and Negative Syndrome Scale (PANSS-N) and the Scale for the Assessment of Negative Symptoms (SANS) in patients with bipolar disorder. We also aimed to confirm these correlations in patients with schizophrenia.