We investigated (a) whether psychosocial factors (experienced stress, anticipatory worry, social detachment, sleeping disturbances, alcohol use) predict the course of paranoid ideation between the ages of 24 to 50 years and (b) whether the predictive relationships are more likely to proceed from the psychosocial factors to paranoid ideation, or vice versa. The participants (N = 1534–1553) came from the population-based Young Finns study. Paranoid ideation and psychosocial factors were assessed by reliable self-report questionnaires in 2001, 2007, and 2011/2012. The data were analyzed using growth curve and structural equation models. High experienced stress, anticipatory worry, social detachment, frequent sleeping disturbances, and frequent alcohol use predicted more paranoid ideation. More risk factors predicted increasing paranoid ideation. There were bidirectional predictive relationships of paranoid ideation with experienced stress, anticipatory worry, social detachment, and sleeping disturbances. The link between alcohol use and paranoid ideation was only correlative. In conclusion, paranoid ideation increases by reciprocal interactions with stress, worry, social detachment, and sleeping disturbances. The findings support the threat–anticipation model of paranoid ideation, providing important implications for treatment of paranoia.

We studied the pattern of personality development in a longitudinal population-based sample of 752 American adolescents. Personality was assessed reliably with the Junior Temperament and Character Inventory at 12, 14, and 16 years of age. The rank-order stability of Junior Temperament and Character Inventory traits from age 12 to 16 was moderate (r = .35). Hierarchical linear modeling of between-group variance due to gender and within-group variance due to age indicated that harm avoidance and persistence decreased whereas self-directedness and cooperativeness increased from age 12 to 16. Novelty seeking, reward dependence, and self-transcendence increased from age 12 to 14 and then decreased. This biphasic pattern suggests that prior to age 14 teens became more emancipated from adult authorities while identifying more with the emergent norms of their peers, and after age 14 their created identity was internalized. Girls were more self-directed and cooperative than boys and maintained this advantage from age 12 to 16. Dependability of temperament at age 16 was mainly predicted by the same traits at earlier ages. In contrast, maturity of character at age 16 was predicted by both temperament and character at earlier ages. We conclude that character develops rapidly in adolescence to self-regulate temperament in accord with personally valued goals shaped by peers.

Borderline personality disorder can be characterized in terms of a profile of abnormal deviations on multiple personality dimensions using the temperament and character inventory (TCI). Borderline patients show poor character development, including low TCI self-directedness (irresponsible, blaming) and low TCI cooperativeness (hostile, intolerant). Their temperament is explosive or unstable due to a combination of high TCI harm avoidance (anxious, shy), high TCI novelty seeking (impulsive, quick-tempered), and low reward dependence (cold, aloof). Consequently they are usually dysthymic with an admixture of anxiety and anger, and regulate their social problems and intense emotions in immature ways. Genetic and psychobiological studies have led to identification of biological correlates of each of the TCI dimensions of personality, including individual differences in regional brain activity, psychophysiological variables, neuroendocrine abnormalities and specific gene polymorphisms. Each dimension of personality involves complex non-linear interaction of multiple genetic and environmental factors and, in turn, each personality dimension interacts with the others in influencing the way an individual directs and adapts to his or her life experiences. Systematic clinical trials have shown that these personality variables predict the response to pharmacological and psychotherapeutic treatments. For example, high harm avoidance and low self-directedness predict slower response and more rapid relapse with both antidepressants and cognitive-behavioral therapy. Treatment with drugs and/or psychotherapy can be individually matched to the patient's profile of temperament and character traits, rather than treating a heterogeneous group of patients as if they had a discrete, homogeneous illness. Fundamental change in cognitive schemas depends on attention to all aspects of character, especially self-transcendence, which has previously been neglected in cognitive-behavioral therapy. Personality integration requires non-resistance to our natural intuitive awareness, rather than intensified intellectual and emotional defenses.

We studied the developmental trends of temperament and character in a longitudinal population-based sample of Finnish men and women aged 20–45 years using the Temperament and Character Inventory model of personality. Personality was assessed in 1997, 2001, and 2007 (n = 2,104, 2,095, and 2,056, respectively). Mean-level changes demonstrated qualitatively distinct developmental patterns for character (self-directedness, cooperativeness, and self-transcendence) and temperament (novelty seeking, harm avoidance, reward dependence, and persistence). Character developed toward greater maturity, although self-transcendence decreased with age. However, self-transcendence was the strongest predictor of overall personality change. Cohort effects indicated lower level of self-transcendence and higher level of self-directedness and cooperativeness in younger birth cohorts. Regarding temperament, novelty seeking decreased and persistence increased slightly with age. Both high novelty seeking and high persistence predicted overall personality change. These findings suggest that temperament and character traits follow different kinds of developmental trajectories.

The theory of path analysis is extended by considering a multivariate system of correlations from a dual perspective. Intrinsic factors exert a unidirectional influence on both the variance and covariance of dependent factors. In contrast, extrinsic factors have a bidirectional influence on the covariance structure of both antecedent and dependent factors and do not influence intrinsic variability. The mathematical model assumes a formally complete linear system of unitary factors. A coefficient is defined to quantify the influence of adventitious associations and is called a copath. Copaths are compared to path coefficients and to correlations due to common antecedents. The chain properties of these coefficients are derived along with a general formula and computational algorithm. The method is illustrated for multifactorial inheritance in extended pedigrees in the presence of different types of assortative mating.

A general theory of personality and its development is described in terms of four quantitative dimensions of temperament and three quantitative dimensions of character. The four temperament dimensions (harm avoidance, novelty seeking, reward dependence, and persistence) are moderately heritable, moderately stable throughout life, and invariant despite sociocultural influences. The three character dimensions (self-directedness, cooperativeness, and self-transcendence) mature in a stepwise manner from early childhood throughout adulthood. Transitions between levels of maturity are nonlinear functions of temperament, specific genetic influences, social learning, and random life events. Personality development is quantitatively formulated in terms of nonlinear dynamics of a complex adaptive system. The psychosocial interpretation of personality as a fitness-optimizing process is described and illustrated in terms of available data about the development of different personality configurations. Several quantitative predictions of this theory of personality development are tested, including the sequence of emergence of the different character dimensions, individual differences in the development of stable temperament configurations, and the effects of sociocultural influences. The theoretical predictions agree with available empirical data and suggest many hypotheses for future developmental research, including etiological, dynamic, and therapeutic studies.

Background. Borderline personality disorder (BPD) is often co-morbid with major depression and may complicate its treatment. We were interested in differences in genetic and developmental risk factors between depressed patients with or without a co-morbid BPD.

Method. Out-patients with major depressive disorder were recruited for two treatment trials. Assessment of depressed patients included the assessment of personality disorders, developmental risk factors and DNA samples for genetic analyses.

Results. In each study there was a significant association between the 9-repeat allele of the dopamine transporter (DAT1) and BPD, with odds ratios (OR) >3 and p[les ]0·02. This association remained significant when developmental risk factors for BPD (childhood abuse and neglect and borderline temperament) were also included in the analyses. The OR was even larger in the depressed patients aged [ges ]35 years (OR 9·31, p=0·005).

Conclusion. This replicated association in depressed patients between the 9-repeat allele of DAT1 and BPD may provide clues to understanding the neurobiology of BPD. The finding that the association is larger in the older depressed patients, suggests that the 9-repeat allele may be associated with a poorer prognosis BPD, rather than a young adult limited variant of BPD.

Normal and abnormal personality development can be quantified in terms of 15 specific steps in the self-organization of character as a complex adaptive system. Character is measured as three dimensions of Self-directedness, Cooperativeness, and Self-transcendence, each with five components corresponding to steps in personality development. Each of these steps is differentially influenced by heritable temperament dimensions, antecedent steps in character development, and life experiences. Predictions about the nonlinear dynamics of personality development, such as equifinality and multifinality, are confirmed in longitudinal data about individuals representative of the general population. The stepwise development of character determines large differences between individuals in their risk of psychopathology, as well as varying degrees of maturity and health.

For many years we and other colleagues in the Department of Psychiatry at Washington University School of Medicine in St Louis, Missouri have been concerned with the need to develop widely accepted, valid diagnostic criteria for psychiatric disorders. The aim has been to identify patient groups as homogeneous as possible. Diagnostic criteria, such as those used in this study, were therefore developed with the goal of maximising specificity (i.e. reducing false positives) while keeping sensitivity as high as possible (i.e. keeping false negatives low).

The assumptions and properties of the Multifactorial Model of Disease Transmission are described, using the principles of quantitative genetics. No assumptions are made about the relative importance of genetic and environmental factors in the transmission of a disorder. The usefulness of the Model is discussed as a device for quantifying family data, discriminating between different modes of transmission and studying variations in disorders according to such clinical variables as age, sex, and severity of illness.

When only one form of a disorder can be distinguished, the degree to which the disorder is transmissible can be measured, and the relative importance of familial factors in the aetiology can be assessed. The assumptions which underlie the Model cannot be tested.

When two or more forms of a disorder can be distinguished, family and population data can be used to test the underlying assumptions of the Model. A good fit of the Model to the observed data indicates that the two subforms of the disorder represent different degrees of the same normally distributed process. This implies that the relative importance of transmissible and non-transmissible factors is the same in determining each subform of the disorder. The testability of the Multifactorial Model with multiple thresholds offers an opportunity for relating and understanding heterogeneous subforms of a disorder, for specifying the relationship between spectrum disorders, and for classifying psychiatric disorders.

Hysteria (Briquet's Syndrome) and sociopathy cluster in the same families instead of segregating as independent traits. Assortative mating between hysterics and sociopaths increases the observed similarity between relatives, but the familial association between sociopathy and hysteria remains after taking assortative mating into account. The Multifactorial Model of Disease Transmission with three thresholds related to severity and sex accounts for population and family data about sociopathic men, sociopathic women, and women with hysteria. The data were obtained for 227 first-degree relatives and for 800 subjects in the general population.

Depending on the sex of the individual and its severity, the same aetiological process may lead to different, sometimes overlapping, clinical pictures. Specifically, analysis indicates that hysteria in women is a more prevalent and less deviant manifestation of the same process that causes sociopathy in women.