years ago. If patients who are clinically depressed complete a personal -
ity inventory , they tend to score extremely high on measures of Neuroti -
cism. After successful treatment or after spontaneous remission, these
patients typically score substantially lower on Neuroticism—althoughstill well above average. One interpretation of this change in personalityscores is that the acute state of depression distorts the measurement ofpersonality , giving exaggerated, state-influenced Neuroticism scores(Hirschfeld et al., 1983). But we now know that clinical depression is abrain disease; we also know that brain diseases can alter personalitytraits. From this perspective it can be argued that personality assess -
ments during depressed states are not distorted; they reflect a real, if
temporary , increase in Neuroticism. Indeed, one might say that an acuteincrease in the level of Neuroticism is one of the major symptoms ofclinical depression.
CASE STUDIES IN STABILITY
The same individuals must be studied at least twice in order to calculatethe stability coefficients on which we have focused so much attention.But these coefficients are still group statistics, showing the extent towhich the same ordering of individuals along a dimension is maintainedover time. A less scientific but perhaps more easily grasped way to ex-amine stability or change is by comparing the personality profiles of in-dividuals at two time periods. Figures 5–7 provide examples of individ -
uals in our studies tested in 1980 and again in 1986 (Costa, 1986): The
1980 scores are joined by broken lines; the 1986 scores, by solid lines.
Figure 5 gives the NEO-PI profile of a woman (Case 1) who de -
scribed herself as a homemaker; she was 62 when she completed the
second administration. The first five columns of the profile show herstanding on the five domains; we can see that she is average in Neuroti -
cism and Agreeableness, low in Extraversion and Openness, and high in
Conscientiousness (A and C were measured only in 1986). Her facetscores are given in the next three sets of columns. It is clear that herscores are almost identical on the two occasions; even the relatively finedistinctions within facets are preserved, most strikingly for Extra -
version. The only notable change is an increase from average to very
high in Openness to Values. Does this represent a temporary change inattitudes or a permanent rethinking that may lead to greater opennessQualifications and Rival Hypotheses 133