Effect of childhood physical abuse on social anxiety is mediated via reduced frontal lobe and amygdala-hippocampus complex volume in adult clinical high-risk subjects.

BACKGROUND

Childhood adverse experiences (CAE) are associated with clinical psychiatric disorders and symptoms, and with volumetric abnormalities in the amygdala-hippocampus complex (AmHiC) and frontal lobe (FroL) in adulthood.

AIM

To study whether CAE are associated with reduced AmHiC and FroL and whether these structures mediate the effect of CAE on social anxiety and depression.

METHOD

In seven European centres, 374 patients with recent onset of psychosis (n = 127), clinical high-risk to psychosis (n = 119) or recent onset of depression (n = 128) were scanned with MRI and their FroL and AmHiC volumes were measured. They all completed self-report scales for assessment of CAE, social anxiety and depression.

RESULTS

Of the CAE domains, physical abuse was associated specifically with reduced grey and white matter volumes of FroL and AmHiC in psychotic and high-risk patients. After controlling intracranial volume, PhyAb associated significantly with FroL and its grey matter volume in high-risk patients only. In mediation analyses, the effect of physical abuse on social anxiety was mediated via reduced FroL grey mater volume in high-risk patients. In them, when the effects of AmHiC and depression were controlled, the effect of physical abuse on social anxiety was mediated via FroL grey matter volume reduction.

CONCLUSIONS

Childhood physical abuse is associated with reduced frontal lobe and amygdala-hippocampus complex volume in adult subjects with psychotic symptoms. Reduced frontal lobe and amygdala-hippocampus complex volume mediate the effect of physical abuse on social anxiety in high-risk patients. The effect of physical abuse on depression-independent social anxiety is mediated via reduced frontal lobe.