Forty-two percent of a nonclinical sample of urban 18 year olds displayed some degree of personality dysfunction. This rate of disturbance is similar to a previously reported rate for 13 year olds, but higher than the prevalence rate for 16 year olds. Thus, early and late adolescence seem to represent "at risk periods" for the genesis of character pathology. 2. In late adolescence, the form of this disturbance is as follows: 40% fall into a histrionic, borderline, narcissistic cluster, whereas nearly 30% demonstrate an atypical or mixed picture. This differs markedly from the distribution of dysfunction in earlier subphases. 3. Thirty-eight percent of the disturbed sample showed evidence of dysfunction at all three subphases (early, middle, and late), whereas 62% fluctuated in or out of disturbance at one subphase or another. 4. There was a notable lack of consistency with respect to type of personality dysfunction from both a group and individual perspective, except for paranoid, schizoid, and schizotypal disturbance. This particular cluster retained both group and individual stability from age 13 to 18. 5. Two trends were evident however: teenagers who initially presented as avoidant, dependent, compulsive, or passive-aggressive seemed to grow out of their dysfunction. By age 18, hardly any of the original subjects remained in this cluster, and most had become clear. Secondly, most of the adolescents identified as antisocial in early or middle adolescence migrated into the histrionic, narcissistic, borderline cluster in late adolescence. This latter group showed a steady increase throughout the time span studied, suggesting the importance of developmental factors.
