Objectives:
To examine olfactory identification (OI) ability in war veterans with post-traumatic stress disorder (PTSD) as a probe of putative orbitoprefrontal dysfunction and to explore the utility of OI ability in predicting aggressive and impulsive behaviour in this clinical population.
Methods:
Participants comprised 31 out-patient male war veterans with PTSD (mean = 58.23 years, SD = 2.56) recruited from a Melbourne Veterans Psychiatry Unit, and 31 healthy age- and gender-matched controls (mean = 56.84 years, SD = 7.24). All participants were assessed for PTSD, depression, anxiety and alcohol misuse; OI; performed neurocognitive measures of dorsolateral prefrontal, lateral prefrontal and mesial temporal functioning; and completed a self-report assessment of aggression.
Results:
War veterans with PTSD exhibited significant OI deficits (OID) compared with controls, despite un-compromised performance on tests of verbal fluency, verbal paired associate learning, visuospatial planning and construction, and attention and motor inhibition. OIDs remained after covaring for IQ, anxiety, depression and alcohol misuse. No significant smoking or medication effects were observed. OIDs were significant predictors of aggressive and impulsive behaviour.
Conclusions:
This research contributes to emerging evidence of orbitoprefrontal dysfunction in the patho-physiology underlying PTSD. This is the first study to report OID as a strong predictor of impulsive and aggressive behaviour in this clinical population. It prompts research to further explore the potential diagnostic utility of OIDs in the assessment of PTSD. Such measures may help delineate the complexity of PTSD symptom presentation and support the targeted interventions for impulsive aggressive behaviour.
