Pre-morbid and outcome correlates of first episode mania with psychosis: is a distinction between schizoaffective and bipolar I disorder valid in the early phase of psychotic disorders?

Objectives: The validity of schizoaffective disorder (SA) diagnosis has for long been a matter of controversy and its delineation from bipolar I disorders (BD) has often been questioned. However, most studies have been conducted in chronic samples and have therefore been biased towards patients with poorer outcome, which may have hampered the possibility to identify significant differences between both diagnoses.

Methods: 108 subjects presenting a first DSM-III-R manic episode with psychotic features were assessed at baseline and 12 months after stabilisation on symptoms and functional characteristics, and patients with BD (n=87) were compared with those with SA bipolar subtype (SAB) (n=21).

Results: SAB patients had a higher prevalence of first degree relatives with schizophrenia and a lower premorbid functional level. They had a longer prodromal phase, a longer duration of untreated psychosis and remained symptomatic for a longer period. They also had higher levels of positive symptoms in the acute manic phase; however, with two exceptions, the type of psychotic symptoms were similar in both groups. At stabilisation and 12 months after stabilisation, SA patients had higher levels of negative symptoms, with poorer functional level at 12 months.

Conclusions: These data suggest SA is a valid diagnosis in the early phase of psychotic disorders considering it defines a subgroup of first episode psychotic mania patients with distinct characteristics compared to BD. While a dimensional approach to diagnosis may be more adapted to this phase of illness, SA disorder offers, in the context of categorical classifications, a useful intermediate category that reflects a clinical reality.