Family-genetic studies and identification of valid diagnostic categories in adult and child psychiatry

de Paula V, Pires T, Michelon L, Camilo C, Esteban N, Pereira A, Schalling M, Vallada H. Shorter telomere length and suicidal ideation in familial bipolar disorder

Bipolar Disorder (BD) has recently been related to a process of accelerated aging, with shortened leukocyte telomere length (LTL) in this population. It has also been observed that the suicide rate in BD patients is higher than in the general population, and more recently the telomere length variation has been described as shorter in suicide completers compared with control subjects. Objectives The aim of the present study was to investigate if there is an association between LTL and BD in families where two or more members have BD including clinical symptomatology variables, along with suicide behavior. Methods Telomere length and single copy gene ratio (T/S ratio) was measured using quantitative polymerase chain reaction in a sample of 143 relatives from 22 families, of which 60 had BD. The statistical analysis was performed with a polygenic mixed model. Results LTL was associated with suicidal ideation (p = 0.02) as that there is an interaction between suicidal ideation and course of the disorder (p = 0.02). The estimated heritability for LTL in these families was 0.68. In addition, covariates that relate to severity of disease, i.e. suicidal ideation and course of the disorder, showed an association with shorter LTL in BD patients. No difference in LTL between BD patients and healthy relatives was observed. Conclusion LTL are shorter in subjects with familial BD suggesting that stress related sub-phenotypes possibly accelerate the process of cellular aging and correlate with disease severity and suicidal ideation.

Early Onset Dysthymic Disorder in Children and Adolescents: Clinical Implications and Future Directions

Early onset dysthymic disorder (EODD) is a serious psychiatric disorder that is associated with impaired social and relationship functioning, comorbid psychiatric conditions, a chronic course and increased risk for adult affective disorders. Unlike major depressive disorder (MDD) in childhood, which has been the focus of ongoing research, EODD has been relatively neglected in clinical practice and research. This paper reviews and evaluates EODD research findings and outlines pertinent clinical and research implications.

Tic disorders

The picture that emerges is one of complex behavioral phenotypes that alter over the course of CNS development. While many cases are mild and may not come to medical attention, others are chronic and disabling. The aim of this article is to provide an overview of recent progress in understanding phenomenology, epidemiology, genetics, neurobiology, and treatment of tic disorders.

The genetic basis of persistence and recovery in stuttering

Although past research has provided evidence of a genetic component to the transmission of susceptibility to stuttering, the relationship between the genetic component to stuttering and persistence and recovery in the disorder has remained unclear. In an attempt to characterize this relationship, the immediate and extended families of 66 stuttering children were investigated to determine frequencies of cases of persistent and recovered stuttering. Pedigree analysis and segregation analysis were used to examine patterns of transmission. The following questions were investigated: 1. Is there a sex effect in recovery from stuttering? Here, we sought to test the hypothesis that females are more likely to recover than males, leading to the change in sex ratio from approximately 2:1 males to females close to onset of the disorder, to 4 or 5:1 in adulthood. 2. Is persistence/recovery in stuttering transmitted in families? If recovery/ persistence appears to be transmitted, (a) are recovered and persistent stuttering independent disorders?; (b) is recovery a genetically milder form of persistent stuttering?; or (c) is persistence/recovery transmitted independent of the primary susceptibility to stuttering? Results indicated sharply different sex ratios of persistent versus recovered stutterers in that recovery among females is more frequent than among males. It was found that recovery or persistence is indeed transmitted, and further, that recovery does not appear to be a genetically milder form of stuttering, nor do the two types of stuttering appear to be genetically independent disorders. Data are most consistent with the hypothesis that persistent and recovered stuttering possess a common genetic etiology, and that persistence is, in part, due to additional genetic factors. Segregation analyses supported these conclusions and provided statistical evidence for both a single major locus and polygenic component for persistent and recovered stuttering.

Comorbidity between dysthymic and major depressive disorders: a family study analysis

There is an extremely high rate of comorbidity between Dysthymic Disorder (DD) and Major Depressive Disorder (MDD). We used family study data to test four competing models of the relationship between DD, MDD, and comorbid DD/MDD: (1) DD, MDD, and DD/MDD are all variants of a single condition; (2) MDD and DD/MDD are similar, but differ from DD; (3) DD and DD/MDD are similar, but differ from MDD; and (4) all three conditions are distinct disorders. Subjects were the first-degree relatives of 22 outpatients with DD (n = 103), 45 outpatients with MDD (n = 207), 75 outpatients with comorbid DD/MDD (n = 343), and 45 normal controls (n = 229). Best-estimate diagnoses of relatives were derived using direct and family history interviews. Relatives of patients with DD and comorbid DD/MDD exhibited significantly higher rates of DD than relatives of patients with MDD and normal probands. The rate of comorbid DD/MDD was significantly higher in the relatives of patients with DD/MDD than the relatives of normal probands. Finally, the relatives of patients with MDD and comorbid DD/MDD exhibited significantly higher rates of MDD than the relatives of normal controls. Although none of the models received unambiguous support, some were more plausible than others.

Genetics of stuttering: a critical review

The fact that stuttering runs in families has been documented over a long period and has led to speculations and research about the role of a genetic component to this disorder. Although the genetic factor cannot be proved by familial aggregation and twin studies alone, such research has continued to provide support for a relationship between stuttering and genetics. The purposes of this article are to review and critique the research in this area. The article first assesses research methodologies that have been employed in familial studies of stuttering. It proceeds to review and critique incidence, twin, and aggregation studies. In addition, it includes sections on subgroups, genetic models of stuttering, and implications for future research as well as for clinical work. With a focus on improved methodology and recent findings, a current perspective on our knowledge of the genetic component to stuttering is provided. Among other conclusions, the article emphasizes that failure to consider epidemiologic factors has probably biased previous results regarding the genetics of stuttering. New preliminary data also appear to provide evidence that spontaneous recovery and chronicity are influenced by genetic factors. Generally, however, the review of incidence and twin studies, as well as of evidence for the various inheritance models, confirms previous conclusions about the interaction between genetic and environmental factors in stuttering.

Genetic transmission and improved diagnosis of schizophrenia from pedigrees of adoptees

In previous investigations of the prevalence of schizophrenic illness among the biological relatives of schizophrenic adoptees in Copenhagen and the remainder of Denmark, the operation of heritable spectrum illness was clearly implicated. The findings supporting that conclusion are briefly summarized. Classical chronic schizophrenia was found almost exclusively in the biological relatives of chronic schizophrenic probands and its prevalence was ten times greater than that in the biological relatives of controls. These were global diagnoses, made without knowledge of the relationships and family histories of the subjects, and based upon the descriptions of dementia praecox or schizophrenia by Kraepelin and Bleuler. They showed considerably greater sensitivity and at least equal specificity in comparison with diagnoses made on the same material in accordance with operational criteria as exemplified by DSM-III. The prevalence of a disorder in the biological relatives of adoptees with that disorder in comparison with biological relatives of control adoptees offers a useful test for the expression of genetic factors in the disorder, but also a much needed evaluation of the validity of diagnoses based on clinical observation.

Australasian field trials of the Mental and Behavioural Disorders section of the draft ICD-10

Field trials of the "Mental and Behavioural Disorders" section of the 1987 draft of the ICD-10 have been co-ordinated for the World Health Organisation by a number of regional centres. The design of the field trials and the major features of ICD-10 are briefly discussed. The results of the field trial in the Western Pacific region are described, and compared with the results of the original DSM-III field trials. ICD-10 appears to be an acceptably reliable diagnostic system, and the ratings of its feasibility and utility by participating clinicians suggest that it will be seen as a distinct advance over ICD-9.

Perinatal factors in the expression of Tourette's syndrome: an exploratory study

The search for nongenetic factors that mediate the expression of a genetic vulnerability to Tourette's syndrome (TS) is an important undertaking that may provide valuable clues concerning the pathophysiology of this disorder as well as potential treatment approaches. In a direct interview study, the perinatal experiences of 31 TS patients were compiled in an effort to identify risk factors associated with tic severity. Severity of maternal life stress during pregnancy, gender of the child, and severe nausea and/or vomiting during the first trimester were found to be significantly associated with current tic severity. Future longitudinal studies of "at-risk" children are needed to confirm these findings. Set in the context of a known chromosomal site for the TS diathesis, such studies will permit the identification and quantification of risk and protective factors in the expression of TS and further develop TS as a model neuropsychiatric disorder for the study of gene-environment interactions.