Grey matter and other structural brain abnormalities are consistently reported in first-onset schizophrenia, but less is known about the extent of neuroanatomical changes in first-onset affective psychosis

To determine which brain abnormalities are specific to (a) schizophrenia and (b) affective psychosis

We obtained dual-echo (proton density/T2-weighted) magnetic resonance images and carried out voxel-based analysis on the images of 73 patients with first-episode psychosis (schizophrenia n=44, affective psychosis n=29) and 58 healthy controls

Both patients with schizophrenia and patients with affective psychosis had enlarged lateral and third ventricle volumes. Regional cortical grey matter reductions (including bilateral anterior cingulate gyrus, left insula and left fusiform gyrus) were evident in affective psychosis but not in schizophrenia, although patients with schizophrenia displayed decreased hippocampal grey matter and increased striatal grey matter at a more liberal statistical threshold

Both schizophrenia and affective psychosis are associated with volumetric abnormalities at the onset of frank psychosis, with some of these evident in common brain areas

In low-and middle-income countries people with schizophrenia are reported to experience better outcomes than those in high-income countries

To examine structural brain differences in people with first-episode psychosis and controls in Brazil

Magnetic resonance imaging using voxel-based morphometry was performed on 122 people with first-episode psychosis and 94 controls

There were significant decreases in grey matter in the left superior temporal and inferior prefrontal cortices, insula bilaterally and the right hippocampal region in first-episode psychosis (P<0.05, corrected for multiple comparisons). The subgroup of people with schizophrenia (n=62) exhibited a similar pattern of decrease in grey matter relative to controls

Structural abnormalities reported in psychosis in high-income countries are also present in first-episode psychosis in Brazil

First-episode psychosis is typically preceded by a prodrome in which there is deterioration in global and social functioning

To examine whether the duration of the prodromal phase influences grey and white matter volumes at the onset of psychosis

Eighty-two people were scanned using magnetic resonance imaging when they developed a first episode of psychosis. The duration of the prodromal phase was estimated from detailed interviews and medical records. Voxel-based morphometry was used to assess neuroanatomical abnormalities

A long prodromal phase was associated with smaller grey matter volumes in the cingulate, frontal and left insular cortex, and with less white matter volume bilaterally in the superior longitudinal and uncinate fasciculi and the cingulum

The severity of volumetric abnormalities in first-episode psychosis was greater in those with a long prodrome