Background: The pre-morbid personality profile 'autonomic lability' (e.g. elevated neuroticism, frequent somatic complaints and increased interpersonal sensitivity) is suggested to be an antecedent of major depression. Recently, we reported that the psychometric profile of healthy first-degree relatives of patients with an affective disorder (so-called high-risk probands; HRPs) was characterized by the personality trait 'rigidity' in association with 'autonomic lability' and speculated that such a profile might be a potential candidate for a true vulnerability marker for affective disorders. Because one major prerequisite for any valid vulnerability marker is its stability over time, we re-examined our HRPs about four years after index assessment.
Methods: Sixteen HRPs from the initial sample (n=54) participated in the follow-up investigation which, on average, took place 47 months after index assessment. All these HRPs had remained mentally healthy during the follow-up period.
Results: The psychometric profile was remarkably stable over the four-year period when considering the total group of the 16 HRPs. On an individual level, similar findings were obtained. Allowing a fluctuation within a narrowly defined 'band width', a constancy of the self-ratings was found in 75% of the HRPs, within a broader 'band width' this was the case in 88% of the HRPs.
Limitations: The power of the present observations appears to be somewhat limited due to the still small sample size of HRPs re-investigated and the fact that the control probands were not yet re-examined.
Conclusions: The present follow-up findings in 16 probands at high risk for an affective disorder indicate a sufficient stability of the psychometric profile over time, so that this requirement for a true vulnerability marker is fulfilled.