Dopamine D2 receptor gene (DRD2) haplotypes and the defense style questionnaire in substance abuse, Tourette syndrome, and controls

The defence style questionnaire (DSQ) was administered to Caucasian males consisting of 123 subjects from a V.A. addiction treatment unit (ATU), 42 Tourette syndrome (TS) subjects, and 49 controls. For the ATU and TS subjects, there was a significant decrease in the mean score for mature defenses and a significant increase in mean score for immature defenses compared to controls. Many of the individual subscores showed the same significant differences. Dopamine D2 receptor (DRD2) gene haplotypes, identified by allele specific polymerase chain reaction of two mutations (G/T and C/T) 241 base pairs apart, were determined in 57 of the ATU subjects and 42 of the controls. Subjects with the 1 haplotype tended to show a decrease in mature and an increase in neurotic and immature defense styles compared to those without the 1 haplotype. Of the eight times that the subscale scores were significant for haplotype 1 versus non-1, they were always in this direction. There results suggest that the DRD2 locus is one factors controlling defense styles. The difference in the mean scores between controls and substance abuse subjects indicates that other genes and environmental factors also play a role.

Genetic and environmental factors in premenstrual symptom reporting and its relationship to depression and a general neuroticism trait

Previous work has indicated a genetic contribution to premenstrual symptom reporting, regularity and menarche but no genetic contribution to cycle length, and no consistent genetic contribution to premenstrual symptom reporting. This paper reports the results (n = 634) of multivariate genetic analysis in which premenstrual symptom reporting is included in a general personality factor along with extroversion (E), neuroticism (N) and depression (D). The results showed that N, E, D and PMS all fitted on a common personality factor. There was no evidence for a specific genetic contribution of depression or premenstrual symptom reporting over and above those shown in the common personality factor. There were, however, unique/specific environmental contributions for PMS. For E and N, in contrast, both unique genetic and environmental contributions were apparent.

Influence of hereditary factors in psychogenic disorders

As part of a research project, a sample of 50 pairs of twins (21 pairs of identical twins, 16 pairs of nonidentical twins of the same sex, and 13 pairs of male-female twins, n = 100 test persons) was examined between 1963 and 1969 and recently, 20 years later, followed up. The index twins were drawn from among the patients making use of the services of an outpatient clinic; they had been diagnosed as having psychoneurotic, character-neurotic of psychosomatic disorders. The question again looked into was that of nature versus nurture: identical twins displayed significantly higher similarity with regard to both severity of their neuroses and manifestation of neurotic symptoms than did nonidentical twins. The hereditary factor proved to be of greater import for the continuing childhood neuroses than for the subsiding childhood neuroses. Yet a certain hereditary factor effect was observed for the neuroses which first manifest themselves in adulthood. Our findings indicate that the hereditary factor is not more pronounced in childhood than in adulthood; it is equally effective in adults.

Personality variations in healthy relatives of schizophrenics

A familial relationship between schizophrenia and schizotypal personality disorder is widely acknowledged; the familial relationship between schizophrenia and the broad continuum of schizoid personality variation is less clear. In a comprehensive family study healthy relatives of schizophrenics were compared by self rated personality features with relatives of unipolar depressed patients and with relatives of controls. The dimension of schizoidia was not able to distinguish the groups of relatives. However, relatives of schizophrenics (in particular male relatives) scored higher on 'normalized' personality dimensions such as 'rigidity' and 'neuroticism'. Healthy relatives of probands with unipolar depression revealed a similar deviant pattern.

A developmental genetic analysis of adult personality: extraversion and neuroticism from 18 to 59 years of age

Developmental genetic analyses were conducted on Extraversion (E) and Neuroticism (N) scale scores from nearly 15,000 male and female Finnish twins, ages 18-53 at baseline, who were tested on 2 occasions, 6 years apart. Significant genetic effects on both traits were found, at all ages, in men and women, on each measurement occasion. For E, heritability was invariant across sex but decreased from late adolescence to the late 20s, with a smaller additional decrease at about 50 years of age. Heritability for N also decreased from late adolescence to late 20s and remained stable thereafter. For all ages after the early 20s, heritability of N was significantly higher among women. Means for E and N were sex-dependent and, apparently, influenced by cohort and time of assessment, as well as by age. There was little evidence of new genetic contributions to individual differences after age 30; in contrast, significant new environmental effects emerged at every age.

[The sibling constellation in neurotic patients]

The authors compared the frequency of the positions among siblings in the neurotic and the control group. The investigation was performed on 582 persons, 435 of them had undergone treatment in the psychotherapeutic department for neuroses. The rest of them, the control group, had never been treated for neurosis. It does not seem that the position of the oldest, the youngest and the only child leads to neurotic disorders. The most risky position is evident by the middle sister. However, validity of these findings is limited by methodological reasons.

Antecedents of neurosis in a cohort of 30,344 twins in Sweden

We analyzed questionnaire survey responses in a cohort of 30,344 twins in Sweden, 280 of whom became inpatients due to neurosis within the subsequent 10 years. As a group, they differed substantially in their reported health profile from the survey responders who were not admitted for psychiatric treatment. When subclassified into anxiety, depressive, and other neuroses, these were indistinguishable from each other regarding self-perceived health and personality traits. Women were more likely to be hospitalized for neurosis. These mental and social antecedents for both anxiety and depression are in keeping with the concept of a shared diathesis which is supported by neurophysiological, treatment and genetic epidemiological studies.

[The cytogenetic disorders in the people who took part in the cleanup of the sequelae at the Chernobyl Atomic Electric Power Station and who lived continuously in areas with an unfavorable ecological situation]

Cytogenetic disturbances are manifested now in persons who liquidated aftereffects of the Chernobyl disaster. The character and course of the disturbances depend on the ecological conditions of the region where liquidators live at present. Examination of a group of liquidators with nerve-psychopathologic disorders and accompanying somatic pathology has revealed the presence of cytogenetic disturbances, mainly of the chromosome aberration type. At the same time, in persons who live under conditions of high environment pollution with ejections of industrial enterprises, the number of chromatid aberrations increases, which may be a result of action of chemical mutagens. A tight correlation is revealed between the level of cytogenetic disorders in lymphocytes and expressivity of the secondary immunodeficiency. Elimination of lymphocytes with unstable chromosome aberration is delayed when ecological pollution of the biosphere reaches the high level.

Evidence for genetic influences on personality from self-reports and informant ratings

Self-report data on Extraversion (E) and Neuroticism (N), together with ratings by the co-twin, were obtained from a sample of 826 adult female twin pairs ascertained through a population-based twin register. Data were analyzed using a model that allowed for the contributions to personality ratings of the rater's personality (rater bias) as well as of the personality of the person being rated. For E, but not for N, significant rater bias was found, with extraverted respondents tending to underestimate, and introverted respondents tending to overestimate, the Extraversion of their co-twins. Good agreement between self-reports and ratings by the respondent's co-twin was found for both E and N. Substantial genetic influences were found for both personality traits, confirming findings from genetic studies of personality that have relief only on self-reports of respondents.

[The differential sensitivity to a neurotigenic exposure of rat strains differing by the threshold of nervous system excitability]

The influence was studied of 15-days stressing on the appearance of stable neurosis-like state of rats lines, selected by the excitability of the nervous system. Unconditioned and conditioned components of behaviour were tested: pain sensitivity, behaviour in the open field, level of "anxiety", passive and active defensive avoidance. Differential reactivity was shown of the rats lines to prolonged stressing, depending on the genetically determined level of the nervous system functional state. Interlinear differences in dynamics of the development of neurosis-like state were established.

[Characteristics of the development and mental status of siblings of neurotic children]

150 children were examined. They were divided into two groups. The first group was composed of the children hospitalized with the diagnosis of neurotic disorder, the second one of their brothers and sisters of similar age (7-13) nontreated psychiatrically. There were statistically significant differences between these two groups in the following ways: 1) pathology of the pre- and postnatal periods, 2) psychomotor development and somatic state during the infantile age, 3) emotional development during the preschool period.

Genetic and environmental determinants of the lability of trait neuroticism and the symptoms of anxiety and depression

A genetic analysis was conducted on trait neuroticism and symptoms of anxiety and depression in a five-wave study of 462 twin pairs. Models that assessed the relative importance of genetic and environmental factors to the lability (within-individual variability over time) of these measures were fitted to the data. Previous results concerning the substantial genetic involvement in the level of neuroticism and symptoms were confirmed. However, it was found that neither genes nor the shared environment of the twins was a significant cause of lability of these measures. An attempt was therefore made to identify aspects of individuals' environments that might be responsible for lability of neuroticism and symptoms. Adverse life events were found to predict variability of symptoms, but not of neuroticism. The availability of close social ties or having affectionless control in childhood did not contribute to lability.

The genetics of six neurotic disorders: a twin study

Persons who had met criteria for specific anxiety or depressive neuroses during their lifetime were identified from a sample of 446 pairs of adult twins. Although there was a genetic contribution to neuroticism and to symptoms, there was no inheritance of specific disorders. This concurs with previous work in a sample from the same Australian Twin Registry and with those from a Norwegian sample. It is concluded that while there is a genetic contribution to the predisposing trait, and therefore to the intermittent appearance of symptoms, this contribution is obscured by the grouping of symptoms into diagnoses and by the help seeking which is a prerequisite to clinical diagnosis.

Change in cohabitation and intrapair similarity of monozygotic (MZ) cotwins for alcohol use, extraversion, and neuroticism

We have reported cross-sectional evidence that behavioral similarities of adult monozygotic (MZ) cotwins are associated with their age at initial separation and the frequency of their subsequent social interaction (Kaprio et al., 1987; Rose et al., 1988; Rose and Kaprio, 1988). Twins who separated early and twins in infrequent interaction were less alike. Data for those reports came from a 1981 survey of the Finnish Twin Cohort. The Finnish cohort had been surveyed in 1975 with a similar questionnaire, and we now report a longitudinal analysis of the 1975-1981 surveys. All cohabiting MZ cotwins, ages 18-25 at the 1975 baseline, were followed up in 1981, and pairwise similarities at baseline and follow-up were compared for three groups: MZ pairs that remained cohabiting, separated pairs in which the cotwins retained regular contact with one another, and separated cotwins whose social interactions at follow-up were infrequent. For alcohol consumption and EPI Neuroticism scores, relative similarities of the MZ cotwins at follow-up paralleled the relative frequencies of their social contact; baseline differences in resemblance for Extraversion scores preceded follow-up differences in social interaction. These findings clarify the directional nature of associations found in our cross-sectional data and provide new, more compelling evidence of effects of shared experience on sibling resemblance for some dimensions of adult behavior.

Linkage analysis of pure depressive disease

In a study of the subgroups of unipolar affective disease, 13 families were ascertained as pure depressive disease (PDD) families. Here we investigate linkage relationships between PDD and 30 genetic markers in these families. Using the robust sib-pair method of linkage analysis, evidence for possible linkage or association was found with five loci: the ABO and MNS blood groups, immunoglobulin kappa (IGK), proline rich parotid salivary protein (PR) and glyoxylase-1 (GLO1). Weak evidence of linkage with ABO was supported using the lod score method of analysis. The maximum lod score between PDD and ABO was 1.42 at a male recombination fraction of 0.09 and a female recombination fraction of 0.03. When these results from the sib-pair analysis were combined with the results from two previous sib-pair studies on PDD, the ABO, MNS and IGK loci were found to be significant (P = 0.05, P = 0.005, P = 0.05, respectively, not allowing for multiple tests).

Genes, nerve cells, and the remembrance of things past

Learning produces changes in neuronal architecture, changes that result from learned alterations in gene expression. Insofar as psychotherapy resembles learning, it is also likely to produce anatomical changes. These changes should be detectable by imaging methods and ultimately should yield objective evaluations of outcome.

Anxiety disorders and neuroticism: are there genetic factors specific to panic?

Data from 2,903 adult same-sex twin pairs were analysed to investigate whether the genetic determinants of symptoms of panic are different from those underlying the neuroticism personality trait. Our results suggest that much of the genetic variation influencing the physical symptoms associated with panic is of the nonadditive type, perhaps due to dominance or epistasis. In both sexes these nonadditive genetic effects on physical symptoms influence the reporting of "feelings of panic". In males they also account for as much as half the genetic variance in neuroticism. The remainder is additive and also accounts for the balance of genetic variation in "feelings of panic". In females genetic variance in neuroticism is entirely additive but is not an important source of covariation with either panic symptom. Thus, symptoms of panic seem to be shaped in part by unique genetic influences which do not affect other anxiety symptoms. That a substantial part of the genetic variance in neuroticism in males may be due to the nonadditive effects on physical symptoms of panic may help to explain the rather low correlation between the genetic influences found to affect neuroticism in males and their counterparts in females.

Twin birth and adult psychiatric disorder. An examination of the case records of the Maudsley Hospital

We compared the general distribution of diagnoses in 20,895 patients at the Maudsley Hospital with that of 504 patients born twins, including 117 twins where the co-twin had died before the age of 15. Significant differences in diagnostic distribution were found in the co-twin-dead compared with the co-twin-alive group; the former received diagnoses of schizophrenia, personality disorder, or substance abuse more often than the latter. While there were no overall differences between twins and non-twins, there were relatively more twins in the above three diagnostic groups. We suggest that the factors leading to the death of one twin are implicated in the later psychiatric morbidity of the survivor.

Neuroticism, extraversion, and related traits in adult twins reared apart and reared together

The relative importance of genetic and environmental factors for neuroticism, extraversion, impulsivity, and monotony avoidance were estimated in a sample of 99 monozygotic and 229 dizygotic pairs of twins reared apart (TRA) and a matched sample of 160 monozygotic and 212 dizygotic pairs of twins reared together (TRT). The average age was 58.6 (SD = 13.6); 72% of the twins were 50 or older. Model-fitting analyses verified the importance of genetic factors for all four measures; from 23% to 45% of the total variation was attributable to genetic sources. There was considerable evidence that these factors were operating in a nonadditive manner for extraversion and impulsivity. Shared environment accounted for less than 10% of the variance; some evidence for selective placement was found for neuroticism.

Familial aspects of obsessive-compulsive neurosis

The first-degree relatives of 50 obsessive-compulsive patients and those of matched controls completed the General Health Questionnaire (GHQ) and the Leyton Obsessional Inventory (LOI). Relatives who were identified as possible 'cases' by their high GHQ scores, or by their own or informant relatives' reports, were interviewed using the Schedule for Affective Disorders and Schizophrenia. Index relatives had a significantly higher lifetime prevalence of mental illness (36%) than had those of controls (17%), due mainly to an excess of depressive and neurotic disorders. However, only one relative from each group was diagnosed as having definite obsessive-compulsive neurosis. In addition, the LOI scores were similar for the index and control relatives.