Aims Behavioural manifestations in Parkinson's disease (PD), such as impulsivity or apathy, are most likely driven by differing patterns of predisposing risk factors, including premorbid and current personality traits. This study explores associations of premorbid and current personality traits in PD sufferers with different behavioural syndromes, from the sufferer and carer perspectives.

Methods This is a cross-sectional descriptive study of 94 non-demented PD sufferers with clinically significant apathy, impulse control disorder, or neither. Each participant was administered the 60-item NEOFFI, a measure of premorbid and current personality functioning, for self- and carer-rated scores. Relationships with other clinical variables were explored. Analysis included comparisons of mean NEO-FFI scores using ANOVA/Kruskall-Wallis. Correlations between personality scores from the carer and the PD sufferer were sought.

Results The PD sufferers with impulse control disorder scored higher on neuroticism, extraversion and openness but lower on agreeableness compared to apathy and control-PD group. Carer ratings of personality correlated on all but one personality trait for the apathy group, but correlations between rater-type in the other two groups were not found. Premorbid and current personality ratings across the entire group correlated on all but two of the personality traits.

Conclusions Differences in personality style in the PD sufferers with impulse control disorder compared to other PD sufferers exist. Some changes in personality from the pre-motor to the clinical stage exist in PD.