This revision represents a continuation of the change begun in
DSM-IV (Flaum et al., 1998). In DSM-III, Schneiderian first-rank symptoms
received particular prominence in the diagnosis of schizophrenia;
instead of two characteristic symptoms required to meet criterion A for
schizophrenia, just one characteristic symptom was required if that
symptom happened to be a Schneiderian first-rank symptom. This
special treatment of Schneiderian first-rank symptoms (which overlap
with the construct of bizarre delusions and “special” hallucinations) led
to criterion A becoming excessively complex and redundant in DSMIII-
R. In DSM-III-R, there were three separate criteria A (A1 [two or
more characteristic symptoms], A2 [bizarre delusions], and A3 [special
types of hallucinations — Schneiderian first-rank hallucinations]) — the
DSM-IV review found this to be unnecessarily complicated (Flaum et
al., 1998). In DSM-IV, it was decided to retain criterion A2 while folding
the A3 criterion into A2. In DSM-IV, criterion A2 is stated as a criterion
A note that reads: “Only one Criterion A symptomis required if delusions
are bizarre or hallucinations consist of a voice keeping up a running commentary
on the person's thoughts, or two or more voices conversing
with each other.” This is the note being deleted in DSM-5.