Three year stability of Five-Factor Model personality traits in relation to changes in symptom levels in patients with schizophrenia or related disorders.

Five-Factor Model (FFM) personality traits are related to a wide range of clinical outcome in patients with psychotic disorders. However, it is not sufficiently clear whether psychotic illness, particularly fluctuation in negative symptoms and psychotic relapse, affects personality. The current study examined the 3-year temporal stability of FFM traits in 91 patients with non-affective psychotic disorders with a maximum duration of illness of 10 years and 32 control subjects without a (family member with) a diagnosis of psychotic illness. In patients, change in negative symptoms predicted changes in Neuroticism and (inversely) in Extraversion and Openness. However, when correcting for depressive symptoms, negative symptoms no longer predicted change in any FFM trait. Clinical characteristics, such as psychotic relapse, were also not found to be related to change in FFM traits. Patients showed a slight increase in Conscientiousness levels, the other FFM traits showed mean-level stability. Rank-order stability of the FFM traits was moderate to strong, although weaker for Neuroticism in patients. Our findings indicate that psychotic symptoms exert limited effect on the stability of FFM traits in patients with psychotic disorders. Consistent with general population findings, one should guard against state-trait confusion between Neuroticism/Extraversion and depression.