Biomedical subjects

Gregor Hasler

Publications and source records attributed to Gregor Hasler.

12 recordsLinked to original sources

PubMed2006

Toward constructing an endophenotype strategy for bipolar disorders.

Research aimed at elucidating the underlying neurobiology and genetics of bipolar disorder, and factors associated with treatment response, have been limited by a heterogeneous clinical phenotype and lack of knowledge about its underlying diathesis. We used a survey of clinical, epidemiological, neurobiological, and genetic studies to select and evaluate candidate endophenotypes for bipolar disorder. Numerous findings regarding brain function, brain structure, and response to pharmacological challenge in bipolar patients and their relatives deserve further investigation. Candidate brain function endophenotypes include attention deficits, deficits in verbal learning and memory, cognitive deficits after tryptophan depletion, circadian rhythm instability, and dysmodulation of motivation and reward. We selected reduced anterior cingulate volume and early-onset white matter abnormalities as candidate brain structure endophenotypes. Symptom provocation endophenotypes might be based on bipolar patients' sensitivity to sleep deprivation, psychostimulants, and cholinergic drugs. Phenotypic heterogeneity is a major impediment to the elucidation of the neurobiology and genetics of bipolar disorder. We present a strategy constructed to improve the phenotypic definition of bipolar disorder by elucidating candidate endophenotypes. Studies to evaluate candidate endophenotypes with respect to specificity, heritability, temporal stability, and prevalence in unaffected relatives are encouraged.

Bipolar Disorder↗

PubMed2005

Normal prefrontal gamma-aminobutyric acid levels in remitted depressed subjects determined by proton magnetic resonance spectroscopy.

BACKGROUND: There is growing evidence that the brain gamma-aminobutyric acid (GABA) system is involved in depression. Lowered plasma GABA levels were identified as a traitlike abnormality found in patients with remitted unipolar depression and in healthy first-degree relatives of patients with unipolar depression. Major depressive disorder has been associated with neuroimaging and neuropathological abnormalities in the prefrontal cortex by various types of evidence. As a result, the current study investigates whether GABA levels in the prefrontal cortex differ between unmedicated subjects with remitted major depressive disorder (rMDD) and healthy control subjects. METHODS: Sixteen rMDD subjects and 15 healthy control subjects underwent magnetic resonance spectroscopy. We used a 3 Tesla GE whole body scanner with a homogeneous resonator coil providing a homogenous radiofrequency field and capability of obtaining measurement from the prefrontal cortex. Gamma-aminobutyric acid levels were measured in the ventromedial prefrontal cortex and dorsolateral/anterior medial prefrontal cortex. RESULTS: There was no difference in GABA concentrations between rMDD subjects and healthy control subjects in the ventromedial prefrontal cortex and dorsolateral/anterior medial prefrontal cortex. Secondary analyses provided preliminary evidence for a negative relationship between the glutamate/glutamine (Glx)/GABA ratio and age of onset of major depression in the ventromedial prefrontal cortex. CONCLUSIONS: This result suggests that GABA levels in the prefrontal cortex, if found to be reduced in symptomatic depression, do not represent a persistent characteristic of major depression. Further research is needed to determine brain GABA levels in different brain regions, in different stages of depressive illness, and in different depressive subtypes.

Adult↗

PubMed2005

Obsessive-compulsive disorder symptom dimensions show specific relationships to psychiatric comorbidity.

The goals of this study were to examine relationships among symptom categories in obsessive-compulsive disorder (OCD), to establish OCD symptom dimensions by factor- and cluster-analytic analyses, and to explore associations between OCD symptom dimensions and comorbid neuropsychiatric conditions. A total of 317 OCD participants underwent a systematic diagnostic interview using the Structured Clinical Interview for DSM-IV. OCD symptoms assessed by the Yale-Brown Obsessive-Compulsive Scale Symptom Checklist (N=169) and by the Thoughts and Behaviors Inventory (N=275) were subjected to factor and cluster analyses. An identical four-factor solution emerged in two different data sets from overlapping samples, in agreement with most smaller factor-analytic studies employing the YBOCS checklist alone. The cluster analysis confirmed the four-factor solution and provided additional information on the similarity among OCD symptom categories at five different levels. OCD symptom dimensions showed specific relationships to comorbid psychiatric disorders: Factor I (aggressive, sexual, religious and somatic obsessions, and checking compulsions) was broadly associated with comorbid anxiety disorders and depression; Factor II (obsessions of symmetry, and repeating, counting and ordering/arranging compulsions) with bipolar disorders and panic disorder/agoraphobia; and Factor III (contamination obsessions and cleaning compulsions) with eating disorders. Factors I and II were associated with early onset OCD. This study encourages the use of cluster analyses as a supplementary method to factor analyses to establish psychiatric symptom dimensions. The frequent co-occurrence of OCD with other psychiatric disorders and the relatively specific association patterns between OCD symptom dimensions and comorbid disorders support the importance of OCD subtyping for treatment, genetic, and other research studies of this heterogeneous disorder.

Anxiety Disorders↗

PubMed2005

Asthma and panic in young adults: a 20-year prospective community study.

RATIONALE: Psychologic factors are increasingly recognized to influence the onset and course of asthma. Previous cross-sectional community-based studies have provided evidence for a relatively specific association between asthma and panic. OBJECTIVES: To examine concurrent and longitudinal associations between asthma and panic in young adults. MEASUREMENTS AND MAIN RESULTS: Prospective community-based cohort study of young adults (n = 591) followed between ages 19 and 40. Information was derived from six subsequent semistructured diagnostic interviews conducted by professionals. Cross-sectionally (over the whole study period), asthma was more strongly associated with panic disorder (odds ratio [OR] = 4.0; 95% confidence interval [CI], 1.7, 9.3) than with any panic, which included panic disorder and panic attacks (OR = 2.1; 95% CI, 1.1, 4.5). Longitudinally, after adjusting for potentially confounding variables, active asthma predicted subsequent panic disorder (OR = 4.5; 95% CI, 1.1, 20.1), and the presence of panic disorder predicted subsequent asthma activity (OR = 6.3; 95% CI, 2.8, 14.0). Asthma predicted any panic (OR = 2.7; 95% CI, 1.1, 7.1), whereas any panic did not predict subsequent asthma activity. Associations were stronger in smokers than in nonsmokers, and stronger in women than in men. Smoking, early-childhood anxiety, and a family history of allergy were important confounders of the asthma-panic association. CONCLUSIONS: This is the first long-term follow-up study on asthma and panic. It showed dose-response-type relationships between panic and asthma, and bidirectional longitudinal associations between the two conditions. It provided evidence for familial factors and smoking as possible shared etiologic explanations.

Adult↗

PubMed2005

Major depression predicts an increase in long-term body weight variability in young adults.

OBJECTIVE: To test the hypothesis that major depression predicts an increase in long-term body weight variability (BWV). RESEARCH METHODS AND PROCEDURES: This was a prospective community-based single-age cohort study of young adults (N = 591) followed between the ages of 19 and 40. Following initial screening, information was derived from six subsequent semistructured diagnostic interviews conducted by mental health professionals. Major depression was diagnosed on the basis of DSM criteria. BWV was defined as the root mean square error of a regression line fitted to each individual's BMI values over time. Multiple regression analysis was used to test the association between major depression and BWV while controlling for potentially confounding variables including antidepressant treatment, eating disorder symptoms, and physical activity. We used random effects models to determine the temporal relationship between repeated measures of major depression and body weight change. RESULTS: A highly significant positive association between major depression and BWV was found, whereas major depression was not associated with BMI level or BMI trend. Depression severity showed a dose-response-type relationship with the magnitude of BWV. After controlling for potentially confounding variables including antidepressant use, eating disorder symptoms, smoking, and physical activity, major depression remained a significant predictor of BWV (beta= 0.13, p < 0.001). Longitudinal analysis revealed a unidirectional association between major depression and a later increase in body weight change rate irrespective of antidepressant medication. DISCUSSION: Results from this study implicate depression as an important risk factor for increased BWV. Given increasing evidence for a link between major depression and both diabetes and cardiovascular disease, current results encourage further research on depression, BWV, and negative health outcomes.

Adult↗

PubMed2005

Excessive daytime sleepiness in young adults: a 20-year prospective community study.

OBJECTIVE: Excessive daytime sleepiness (EDS) is a symptom with high clinical and public health importance because of its association with increased risk for accidents, decreased productivity, and impaired quality of life. Little information is available regarding the longitudinal course or clinical correlates of EDS. The aim of this study was to explore associations between self-reported EDS, sleep disorder symptoms, major depression, and anxiety in a longitudinal community study of young adults. METHOD: A prospective single-age community study of young adults (Zurich Cohort Study) was conducted from 1978 through 1999. Information was derived from 6 interviews administered when participants (N = 591) were ages 20, 22, 27, 29, 34, and 40 years. Trained health professionals administered a semistructured interview for health habits and psychiatric and medical conditions. The presence of either or both of 2 symptoms-accidentally falling asleep or excessive need for sleep during the day-was used to establish the presence of EDS. RESULTS: EDS was a common complaint among the study participants, with increasing prevalence with age. Cross-sectionally, EDS was associated with insomnia symptoms, nocturnal hypersomnia, anxiety disorders, somatization, and reduced quality of life. Longitudinally, impaired sleep quality, waking up too early, and anxiety were associated with later EDS. Conversely, EDS was not significantly associated with later anxiety or depressive disorders. CONCLUSIONS: Insomnia symptoms and anxiety are associated with the subsequent occurrence of EDS. Although these findings do not demonstrate causality, insomnia and anxiety disorders are prevalent and treatable conditions, and our results may have important clinical implications for the prevention and treatment of EDS. Whether the results of this study are limited to populations with elevated levels of psychopathology remains to be tested.

Adult↗

PubMed2004

The association between short sleep duration and obesity in young adults: a 13-year prospective study.

STUDY OBJECTIVES: Obesity has become a major health problem with increasing prevalence. Given the limited availability of effective treatment of weight problems, the identification of potentially modifiable risk factors may lead to preventive approaches to obesity. The objective of this study was to test the hypothesis that short sleep duration is associated with obesity and weight gain during young adulthood. DESIGN: Prospective single-age cohort study of young adults. Information was derived from 4 interviews when participants were ages 27, 29, 34, and 40 years. SETTING: Community setting. PARTICIPANTS: 496 young adults. MEASUREMENTS AND RESULTS: Trained health professionals administered a semistructured interview for psychiatric and medical conditions and health habits. This study showed an association between short sleep duration and obesity (at age 27 years, odds ratio: 7.4, 95% confidence interval: 1.3-43.1) and a negative association between sleep duration and body mass index in young adults. These associations persisted after controlling for a variety of potentially confounding variables, including family history of weight problems, levels of physical activity, and demographic variables. Associations between sleep duration and obesity diminished after age 34 years. There was a trend (P = .08) for average change rate of weight gain to be negatively associated with average change rate of sleep duration. CONCLUSIONS: Because sleep duration is a potentially modifiable risk factor, these findings might have important clinical implications for the prevention and treatment of obesity.

Adult↗

PubMed2004

Application of Prochaska's transtheoretical model of change to patients with eating disorders.

OBJECTIVE: Although eating disorders cause severe somatic and psychological sequelae, a majority of affected patients are not motivated for treatment. The aim of this study was to assess stages of change in patients with eating disorders and to analyze their correlations with clinical characteristics and treatment processes using Prochaska's transtheoretical model of change. METHODS: A consecutive sample (N=88) including outpatients suffering from anorexia (n=29), bulimia (n=32), and eating disorders not otherwise specified (n=27) was recruited from an eating disorders clinic with a low-threshold access. The patients' readiness to change their eating behavior was assessed by a self-rating scale (URICA), and a score for each participant on each subscale (precontemplation, contemplation, action) was derived from the scale. Patients were introduced to a set of eight treatment processes over the course of four treatment sessions. During the four sessions, therapists rated whether or not patients appeared to be using each of the treatment processes. RESULTS: While diagnostic subtype, age, illness duration, and previous treatments were not associated with motivational stages, self-referral was positively correlated to treatment motivation. Emotional involvement, specific behavioral change processes, and beginning a continuing treatment were correlated with more advanced stages of change. CONCLUSION: This study supports the notion of the stages of change as an independent dimension that is relevant for the treatment of eating disorders. The lack of impact of previous, presumably nonspecific treatments on the stages of change underlines the importance to assess and to improve specifically patients' motivation. Therapeutic work towards the mobilisation of emotions with regard to their eating problem as a means to improve readiness to change should be examined in future studies.

Adult↗

PubMed2004

Discovering endophenotypes for major depression.

The limited success of genetic studies of major depression has raised questions concerning the definition of genetically relevant phenotypes. This paper presents strategies to improve the phenotypic definition of major depression by proposing endophenotypes at two levels: First, dissecting the depressive phenotype into key components results in narrow definitions of putative psychopathological endophenotypes: mood bias toward negative emotions, impaired reward function, impaired learning and memory, neurovegetative signs, impaired diurnal variation, impaired executive cognitive function, psychomotor change, and increased stress sensitivity. A review of the recent literature on neurobiological and genetic findings associated with these components is given. Second, the most consistent heritable biological markers of major depression are proposed as biological endophenotypes for genetic studies: REM sleep abnormalities, functional and structural brain abnormalities, dysfunctions in serotonergic, catecholaminergic, hypothalamic-pituitary-adrenocortical axis, and CRH systems, and intracellular signal transduction endophenotypes. The associations among the psychopathological and biological endophenotypes are discussed with respect to specificity, temporal stability, heritability, familiality, and clinical and biological plausibility. Finally, the case is made for the development of a new classification system in order to reduce the heterogeneity of depression representing a major impediment to elucidating the genetic and neurobiological basis of this common, severe, and often life-threatening illness.

Affect↗

PubMed2004

Patient satisfaction with outpatient psychiatric treatment: the role of diagnosis, pharmacotherapy, and perceived therapeutic change.

OBJECTIVE: To investigate the influence of diagnosis, type of treatment, and perceived therapeutic change on patient satisfaction following psychiatric treatment for nonpsychotic, nonsubstance-related disorders. METHOD: We mailed questionnaires, including Larsen's Client Satisfaction Questionnaire and Grawe's Bern Inventory of Treatment Goals, to outpatients who had undergone 8 or more therapy sessions 1 year following treatment. RESULTS: Patients with somatoform, eating, and personality disorders were less satisfied than patients with affective, anxiety, and adjustment disorders. Symptom reduction and changes in the interpersonal domain were important outcomes associated with patient satisfaction. Although pharmacotherapy itself was not related to patient satisfaction, patients who perceived improvements in pharmacotherapy as one of the most important treatment outcomes were less satisfied than others. Preliminary evidence shows that coping with specific problems and symptoms is associated with satisfaction among male patients, whereas changes in the interpersonal domain seem to produce satisfaction among female patients. CONCLUSION: Patient-reported change and diagnostic category appear to play a relevant role in generating patient satisfaction. Further research is needed to clarify the interactions between sex, perceived outcome, and satisfaction.

Adult↗

PubMedDate not supplied

Outcome of psychiatric treatment: what is relevant for our patients?

This study investigated relevant outcome domains in the patient's perspective following psychiatric outpatient treatment for non-psychotic, non-substance-related disorders. Questionnaires, including the Client Satisfaction Questionnaire (CSQ) and the Bern Inventory of Treatment Goals (BIT-C) applied as a broad typology of outcome domains, were mailed 1 year after treatment to outpatients who had undergone eight or more therapy sessions. Patients reported a wide range of relevant outcomes, including changes with respect to the interpersonal domain, their self-concept, and existential issues. Changes in depressive and anxiety symptoms were rated as particularly important; the reports of both symptomatic and more integral changes were related to treatment characteristics, patient's diagnostic category, and patient's employment status. Patient satisfaction was particularly related to reported changes in the interpersonal domain. This exploratory study provides evidence that traditional outcome measures that include mood, anxiety, and fear symptoms continue to assess the most important areas for change in patients' views. However, they might miss relevant therapeutic achievements in some of our patients, particularly in those suffering from adjustment and personality disorders. The use of measures that include dimensions such as personal growth, purpose of life, and positive relations with others may record important changes in these patients.

Adaptation, Psychological↗

PubMedDate not supplied

[The University of Rhode Island Change Assessment Scale (URICA)].

The present paper describes a German version of the University of Rhode Island Change Assessment Scale (URICA) called Fragebogen zu Erfassung der Veränderungsbereitschaft (FEVER). The URICA is a questionnaire designed to measure the stages of change. This instrument is well suited for complex problem behavior, because it yields scores for each stage of change for each individual instead of classifying individuals into a single stage. It is based on Prochaska's transtheoretical model of change. This model recognizes that most psychological disorders are characterized by repetitive problem behaviors that are resistant to modification, and that people do not make a simple black or white decision to change their behavior, rather it holds that people change their behavior gradually across different stages. The model has been successfully applied in different areas of health care to help preventive and treatment interventions adjust to clients' readiness for change. The FEVER was used and tested in a cross-sectional study of 129 patients with an eating disorder. It turned out to be an instrument that was easily understood by patients and that yielded the factor structure of the original version. The internal consistency of the scales was good or very good. Means and standard deviations of the scales were comparable to those found using the original instrument. In addition, there was evidence for the predictive and concordant validity of the instrument. We conclude that the FEVER is a valid instrument to assess the motivational dimension of therapeutic change of complex problem behavior.

Adult↗