Right amygdala hypertrophy linked to suicide attempts in schizophrenia patients
MedWire News: Results from an Italian study suggest that right amygdala hypertrophy is associated with an increased risk for suicide attempts in patients with schizophrenia.
Writing in the journal Schizophrenia Research, Gianfranco Spalletta (IRCCS Santa Lucia Foundation, Rome) and team explain that suicide is a major cause of death in patients with schizophrenia.
To investigate whether volumetric abnormalities in brain structures that play a key role in emotion regulation, aggression, and impulse control are associated with suicidality in schizophrenia, the team enrolled 50 outpatients with the mental health disorder and 50 mentally healthy individuals (controls) who were matched for age and gender.
Of the patients with schizophrenia, 14 had a history of one or more suicide attempts, while none of the controls had such a history.
All of the participants underwent structural magnetic resonance imaging of the brain, and volumetric measures were calculated for the lateral ventricles, thalamus, hippocampus, amygdala, caudate, putamen, pallidum and accumbens.
Patients with schizophrenia were also assessed for aggression using the Modified Overt Aggression Scale (MOAS).
The researchers found that mean right amygdala volume was significantly greater in schizophrenia patients with a history of suicide attempts, at 916 mm3, than that in schizophrenia patients without a history of suicidality and controls, at 757 and 788 mm3, respectively.
No other differences in subcortical structure volumes were observed among the participants.
The team also found that schizophrenia patients with a history of suicide attempts had significantly higher scores on the self-aggression and the aggression toward other people subscales of the MOAS than patients without such a history, at 3.714 and 1.714 versus 0.111 and 0.639, respectively.
No significant differences in the other MOAS subscales (ie, verbal aggression and aggression against property) or severity of positive and negative symptoms were observed between schizophrenia patients with and without a history of suicide attempts.
Spalletta et al conclude: "Amygdalar hypertrophy may play a pivotal role in the pathoetiological circuits underlying suicidality in schizophrenia, with potential implications for identification of high-risk patients and suicide prevention."
They add: "Additional research is needed to clarify the role of amygdalar hypertrophy as a neurobiological marker of suicide and self-aggression in schizophrenia."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010
By Mark Cowen