Personality Disorders. Maddux & Mundell pose 4 questions:. 1) What is a PD and how is it different from normal personality?. 2) How are PDs similar to and different from other types of psychological problems?.
Maddux & Mundell pose 4 questions:
1) What is a PD and how is it different from normal personality?
2) How are PDs similar to and different from other types of psychological problems?
3) Is it better to think of PDs as diagnostic categories or as extreme points on a continuum of individual differences?
4) Are there different types of PDs that can be distinguished from one another?
“A PD is an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the individual’s culture, is pervasive and inflexible, has an onset in adolescence or early adulthood, is stable over time, and leads to distress or impairment”
Three important elements to this definition:
General definition of personality
Paranoid PD distrust and suspiciousness such that others motives are interpreted as malevolent
Schizoid PD detachment from social relationships and restricted range of emotional expression
Schizotypal PD acute discomfort in close relationships, cognitive or perceptual distortions, and eccentricities of behavior
According to Maddux & Mundell:
1) difficulty getting along with other people and report histories of disruptive relationships
2) difficulty learning from experience (inflexible)
3) do not accept responsibility for own behavior
4) do not fare well in psychotherapy
Plus a few more from Millon:
5) tenuous stability (trouble bouncing back)
6) adaptive inflexibility (too few strategies)
7) vicious circles
DSM categorical model makes three assumptions:
1) PDs are qualitatively distinct from normal personality
2) PDs are qualitatively distinct from Axis I disorders
3) PDs are qualitatively different from each other
Dimensional models assume:
1) (ab)normal/(mal)adaptive lie on continuum
2) PDs differ quantitatively rather than qualitatively from normal personality
3) PD is extreme and maladaptive variation of normal traits
PDs versus general population
1) Categorical Distribution? (Livesley, Jackson, & Schroeder, 1992)
2) Different “structures”? (Livesley, Jackson, & Schroeder, 1992)
Livesley, W.J., Jackson, D.N., & Schroeder, M.L. (1992). Factorial structure of traits delineating personality disorders in clinical and general population samples. Journal of Abnormal Psychology, 103, 432-440.
Clinical sample (n = 158)
General population sample (n = 274)
Completed 100 personality scales
Two important findings:
No evidence for bimodality on personality scales
Factor structure identical across samples
3) Bright lines? (Widiger, Sanderson, & Warner, 1986)
A “bright line” is a line/definition/description that sharply demarcates different groups/things/elements from one another.
Widiger, T.A., Sanderson, C., & Warner, L. (1986). The MMPI, prototypal typology, and borderline personality disorder. Journal of Personality Assessment, 50, 540-553.
Administered semi-structured interview for each of 81 symptoms of DSM-III PDs
See profile sheet
“The borderlines with only five symptoms had significantly lower elevations than a) the borderlines with seven or eight symptoms on scales D, Pt, Sc, and Si (p < .05) and b) the borderlines with six or more symptoms (n = 34) on scales D, Pt, and Sc (P < .05). They differed significantly from nonborderlines (n = 27) on only the K and Hs scales (p < .05).”
1) Some traits are rooted in biology but no evidence that biology underlies PDs
2) Relative contribution of genes is similar in normal personality and PDs
Models arguing against a distinction
1) Spectrum Model (Axis I amplified into Axis II)
2) Vulnerability Model (Axis II as diathesis for Axis I)
Research arguing against a distinction
1) No differences in etiology (genetic and psychosocial influences on Axes I and II)
2) Temporal stability does not distinguish Axes I and II
3) High degree of comorbidity across Axes I and II
Categorical approach assumes that each PD represents a distinct group of individuals who differ qualitatively from those in other PD categories.
Does not appear to be true
Skodol et al. (1991) found that individuals were given, on average, four PD diagnoses
Widiger et al. (1991) found that 96% of individuals with Borderline PD were given at least one other diagnosis