Biomedical subjects

Robert H Friis

Publications and source records attributed to Robert H Friis.

3 recordsLinked to original sources

PubMed2003

Association chain graphs: modelling etiological pathways.

Multiple time-dynamic and interrelated risk factors are usually involved in the complex etiology of disorders. This paper presents a strategy to explore and display visually the relative importance of different association pathways for the onset of disorder over time. The approach is based on graphical chain models, a tool that is powerful but still under-utilized in most fields. Usually, the results of these models are displayed using directed acyclic graphs (DAGs). These draw an edge between a pair of variables whenever the assumption of conditional independence given variables on an earlier or equal temporal footing is violated to a statistically significant extent. In the present paper, the graphs are modified in that confidence intervals for the strengths of associations (statistical main effects) are visualized. These new graphs are called association chain graphs (ACGs). Statistical interactions cause 'edges' between the respective variables within the DAG framework (because the assumption of conditional independence is violated). In contrast they are represented as separate graphs within the subsample where the different association chains may work within the ACG framework. With this new type of graph, more specific information can be displayed whenever the data are essentially described only with statistical main- and two-way interaction effects.

Alcoholism↗

PubMed2002

Life events and changes in the course of depression in young adults.

BACKGROUND: Few community-based studies have examined the impact of life events, life conditions and life changes on the course of depression. This paper examines associations of life events on depressive symptom onset, improvement, and stability. METHODS: Direct interview data from the Early Developmental Stages of Psychopathology Study (EDSP), a 4-5 year prospective-longitudinal design based on a representative community sample of adolescents and young adults, aged 14-24 years at baseline, are used. Life events were measured using the Munich Event-Questionnaire (MEL) consisting of 83 explicit items from various social role areas and subscales for the assessment of life event clusters categorized according to dimensions such as positive and negative and controllable and uncontrollable. Depressive disorders were assessed with the DSM-IV version of the Munich Composite Diagnostic Interview (M-CIDI). Multiple logistic regression analyses examined the effects of 22 predictors on the course of depression (onset, improvement, stability). RESULTS: Younger age, low social class, negative and stressful life events linked to the family were associated with increased risk of new onset of depression. Anxiety was a significant independent predictor of new onset of depression. Absence of stressful school and family events was related to improvement in depression. The weighted total number of life events predicted stable depression. CONCLUSIONS: The association between life events and the course of depression appears to vary according to the outcome being examined, with different clusters of life events differentially predicting onset, improvement, and stability.

Adolescent↗

PubMed2002

The natural course of DSM-IV somatoform disorders and syndromes among adolescents and young adults: a prospective-longitudinal community study.

OBJECTIVE: Although somatoform disorders are assumed to be chronic clinical conditions, epidemiological knowledge on their natural course based on representative samples is not available. METHOD: Data come from a prospective epidemiologic study of adolescents and young adults in Munich, Germany. Respondents' diagnoses (N = 2548) at baseline and follow-up on average 42 months later are considered. The follow-up incidence, stability as well as selected baseline risk factors (sociodemographics, psychopathology, trauma exposure) for the incidence and stability of somatoform disorders and syndromes are prospectively examined. Diagnostic information was assessed by using the standardized Munich-Composite International Diagnostic Interview (M-CIDI). RESULTS: Over the follow-up period, incidence rate for any of the covered somatoform diagnoses was 25.7%. Stability for the overall group of any somatoform disorder/syndrome was 48%. Female gender, lower social class, the experience of any substance use, anxiety and affective disorder as well as the experience of traumatic sexual and physical threat events predicted new onsets of somatoform conditions, while stability was predicted by being female, prior existing substance use, affective and eating disorders as well as the experience of a serious accident. CONCLUSIONS: At least for a substantial proportion of individuals, the overall picture of somatization seems to be relatively stable, but with fluctuation in the symptom picture over time. Being female, the experience of substance use as well as anxiety disorder seem to constitute risk factors for the onset of new somatoform conditions as well as for a stable course over time.

Adolescent↗