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Biomedical subjects

Douglas R Langbehn

Publications and source records attributed to Douglas R Langbehn.

14 recordsLinked to original sources

Practice effects in the prediction of long-term cognitive outcome in three patient samples: a novel prognostic index.

Practice effects, defined as improvements in cognitive test performance due to repeated exposure to the test materials, have traditionally been viewed as sources of error. However, they might provide useful information for predicting cognitive outcome. The current study used three separate patient samples (older adults with mild cognitive impairments, individuals who were HIV+, individuals with Huntington's disease) to examine the relationship between practice effects and cognitive functioning at a later point. Across all three samples, practice effects accounted for as much as 31-83% of the variance in the follow-up cognitive scores, after controlling for baseline cognitive functioning. If these findings can be replicated in other patients with neurodegenerative disorders, clinicians and researchers may be able to develop predictive models to identify the individuals who are most likely to demonstrate continued cognitive decline across time. The ability to utilize practice effects data would add a simple, convenient, and non-invasive marker for monitoring an individual patient's cognitive status. Additionally, this prognostic index could be used to offer interventions to patients who are in the earliest stages of progressive neurodegenerative disorders.

Adult↗

Probability of obsessive and compulsive symptoms in Huntington's disease.

BACKGROUND: The purpose of this study was to examine the probability of obsessive and compulsive (OC) symptoms across stages of Huntington's disease (HD) with both cross sectional and longitudinal data. METHODS: We present the largest sample to date of individuals at risk for HD (N = 3964). Obsessive and compulsive symptoms were assessed with the Unified Huntington's Disease Rating Scale OC items. RESULTS: The probability of meeting the threshold for obsessions and compulsions increased with greater disease severity. Those with no motor abnormalities ("at risk") had a 7% probability of obsessions and a 3.5% probability of compulsions; the peak probability for obsessions (24%) and compulsions (12%) occurred in patients with advanced disease with significant functional disability. CONCLUSIONS: The probability of OC symptoms is more than three times greater by stages 3 and 4 (clearly manifest disease) than in our at-risk group with no apparent motor abnormalities.

Adult↗

Preparing for preventive clinical trials: the Predict-HD study.

BACKGROUND: The optimal design and outcome measures for preventive clinical trials in neurodegenerative diseases are unknown. OBJECTIVE: To examine measures that may be associated with disease in the largest cohort ever recruited of prediagnosed individuals carrying the gene expansion for Huntington disease (HD). DESIGN: The Predict-HD study is a multicenter observational research study in progress at 17 sites in the United States, 4 in Canada, and 3 in Australia. SETTING: Genetics and HD outpatient clinics. PARTICIPANTS: Five hundred five at-risk individuals who had previously undergone elective DNA analyses for the CAG expansion in the HD gene (predictive testing) and did not currently have a clinical diagnosis of HD. MAIN OUTCOME MEASURES: Basal ganglia volumes on magnetic resonance images, estimated probability of diagnosis (based on CAG repeat length), performances on 21 standardized cognitive tasks, total scores on 3 scales of psychiatric distress, and motor diagnosis based on the Unified Huntington's Disease Rating Scale. RESULTS: Several variables showed progressive decline as the diagnostic ratings advanced toward manifest disease. Estimated probability of diagnosis was associated with Unified Huntington's Disease Rating Scale prediagnostic stages and varied from 15% in persons with no motor abnormalities to nearly 40% in those with abnormalities suggestive of probable disease. Striatal volumes, cognitive performances, and even psychiatric ratings declined significantly with motor manifestations of disease. CONCLUSIONS: The documentation of biological and refined clinical markers suggests several clinical end points for preventive clinical trials. Longitudinal study is critical to further validate possible markers for prediagnosed HD.

Adult↗

Examining the repeatable battery for the assessment of neuropsychological status: factor analytic studies in an elderly sample.

OBJECTIVE: The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), a recently developed cognitive assessment instrument, has been shown to be useful with a variety of neuropsychiatric conditions, but its factor structure has not been examined. METHOD: Using 824 community-dwelling elders, the RBANS was examined with confirmatory and exploratory factor analyses. RESULTS: The existing structure of the RBANS was not supported; however, a two-factor solution was. CONCLUSIONS: Clinicians and researchers using the RBANS should be cautious when interpreting this measure with its existing structure.

Aged↗

Distinguishing between hypochondriasis and somatization disorder: a review of the existing literature.

A valid classification is important for further understanding of the somatoform disorders. The main disorders in this grouping - somatization disorder and hypochondriasis - have lengthy historical traditions and are defined in a contrasting manner. Various authors point to distinguishing demographic and clinical features, but there have been few direct comparisons of patients with these disorders. A review of the literature indicates those domains where differences are most likely to be found. Research assessing these may serve to refine and validate these key somatoform categories and/or dimensions.

Diagnosis, Differential↗

Association of a D2S2944 allele with depression specifically among those with substance abuse or antisocial personality.

Associations have previously been reported between a 124-bp allele at D2S2944 and recurrent, early-onset depression in women. These earlier reports also noted but did not emphasize a possible association between this allele and alcohol-specific depression. We have analyzed the Iowa Adoption Study data to test this association. D2S2944 allele typing was available for 247 subjects from the Iowa Adoption Studies. Information on lifetime affective, alcohol, drug, and antisocial personality (ASPD) disorders was available from a structured interview. We used logistic regression to analyze adjusted and interactive D2S2944 associations with depression. Controlling other risk factors, the 124-bp allele had a strong association with DSM-IV major depression specific to those with histories of alcohol abuse/dependence and/or ASPD. (Overlap between the two prevented further specification of the interaction.) The association was not gender-specific and was not limited to alcohol-related depressive episodes. This relationship appears stronger than the D2S2944 association previously reported for early-onset depression in women. We note that, in combination with additional liabilities towards depression in women and alcoholism/sociopathy in men, the 124-bp allele may provide a basis for the phenomenon of depressive spectrum illness proposed by Winokur.

Adoption↗

White matter volume and cognitive dysfunction in early Huntington's disease.

BACKGROUND: Structural abnormalities of the striatum and cognitive impairments have consistently been shown in patients with Huntington's disease (HD). Fewer studies have examined other cerebral structures in early HD and potential associations with cognition. METHOD: Ten patients with early HD and 10 matched control subjects underwent magnetic resonance imaging to provide quantitative measures (volumes) of cortical gray and white matter and the caudate, putamen, and thalamus. Patients completed the Unified Huntington's Disease Rating Scale, including three cognitive tasks. RESULTS: Although striatal volumes were clearly reduced, white matter was also morphologically abnormal. Cortical gray matter volume was not significantly correlated with cognitive performance. However, the cognitive tasks were most highly correlated with cerebral white matter and, to a lesser degree, striatal volume. CONCLUSIONS: Cerebral white matter volume may be an important variable to examine in future studies of HD.

Adult↗

Specific phobia of illness: search for a new subtype.

Specific phobia of illness makes its appearance in DSM-IV as a new diagnostic subtype, separate from hypochondriasis. A review of the literature indicates that, while there is some support for this new category, studies have not as yet been done that could provide validation. Illness phobia appears to be a significant problem; it is prevalent in the general population and is associated with distress and impairment, including interference with medical care. It appears to be associated with older age, physical illness, and female gender. Group comparisons are needed showing that persons with this phobia can be distinguished from hypochondriasis on the basis of these and other demographic and illness features. We outline a research agenda for demonstrating this separation.

Antidepressive Agents, Tricyclic↗

Genetic and environmental risk factors for the onset of drug use and problems in adoptees.

Applying survival analysis methodology to age-of-onset data from an adoption study (N = 196), we present evidence that risks for both drug use and drug problems (DSM abuse or dependence) are elevated when combined antisocial personality (ASP) and substance abuse is present in the same biological parent. It is increased not only in comparison to adoptees with no known biological risk, but also when compared to adoptees with a biological background for only substance problems or only ASP. Neither of these later groups showed a statistically higher risk when compared with controls. Among adoptees with recurrent drug use, adolescent aggressivity is also elevated when the combined substance abuse/ASP biological diathesis is present. Statistical control for aggressivity diminished but did not eliminate the predictive significance of the combined biological diathesis for drug problems. We also verify, using more refined methodology, our previous reports of gender and adverse adoptive environmental influences on drug-related outcomes in these subjects. We could not document a biology-environment interaction, but power to do so was rather low. We argue that the observed biological associations are broadly consistent with generalization to other substances of an alcoholism phenotype similar to Cloninger's Type II or Babor's Type B.

Adolescent↗

Hypochondriasis and fear of death.

Although fear of death has been linked to hypochondriasis, the relationship of this fear to the disorder has received little study. To address this deficiency, we administered a fear of death scale along with measures of hypochondriasis, including the Whiteley Index and Somatic Symptom Inventory, to 162 general medical outpatients. Partial correlations, controlling for age, between the fear of death scale and both the Whiteley Index and Somatic Symptom Inventory were strongly positive. A factor analysis of the fear of death scale yielded three dimensions-fear of dying, loss of meaning, and fear of separation-that were also highly correlated with hypochondriasis. Fear of death and hypochondriasis showed comparable relationships to age and gender as well as to personality dimensions measured by the NEO Five-Factor Inventory. Fear of death appears to be an integral part of hypochondriasis. Its presence lends support to three models of hypochondriasis-the perceptual, existential, and interpersonal-that correspond to the dimensions of fear of death.

Ambulatory Care↗

Test of an interpersonal model of hypochondriasis.

OBJECTIVE: The aim of this study was to test the interpersonal model of hypochondriasis proposed by Stuart and Noyes. According to this model, hypochondriasis is associated with insecure attachment that in adults gives rise to abnormal care-seeking behavior. Such behavior is associated with interpersonal difficulties and strained patient-physician relationships. METHODS: One hundred sixty-two patients attending a general medicine clinic were interviewed and asked to complete self-report measures. Instruments included the Whiteley Index of Hypochondriasis, Somatic Symptom Inventory, Relationship Scales Questionnaire, Inventory of Interpersonal Problems, NEO Five-Factor Index, and measures of physician-patient interaction. The Structured Diagnostic Interview for DSM-III-R Hypochondriasis was also administered. RESULTS: Hypochondriacal and somatic symptoms were positively correlated with all of the insecure attachment styles, especially the fearful style. These same symptoms were positively correlated with self-reported interpersonal problems and negatively correlated with patient ratings of satisfaction with, and reassurance from, medical care. Hypochondriacal and somatic symptoms were also positively correlated with neuroticism. CONCLUSIONS: The findings indicate that hypochondriacal patients are insecurely attached and have interpersonal problems that extend to and include the patient-physician relationship. These data support the proposed interpersonal model of hypochondriasis.

Adult↗

Childhood antecedents of hypochondriasis.

According to the interpersonal model of hypochondriasis, early environmental adversity may give rise to attachment insecurity that finds adult expression in care-seeking behavior. To identify antecedents of this disturbance, we interviewed general medicine patients and obtained from them self-reports of traumatic events, adverse circumstances, and symptoms experienced in childhood. Patients who met DSM-III-R criteria for hypochondriasis more often reported traumatic events and circumstances, including serious illness or injury. Among all patients, the level of hypochondriacal symptoms in adulthood was correlated with poor health, hypochondriacal worry, and separation anxiety in childhood. These findings are consistent with a growing literature that links childhood adversity to adult hypochondriasis; they support the interpersonal model.

Adult↗

Prevalence and correlates of illness worry in the general population.

The prevalence and correlates of illness worry in the general population were investigated in a representative sample. The authors screened residents of the United States by telephone, and more detailed interviews were conducted with 123 respondents who reported at least 1 month of worry about serious illness in the past 12 months and an equal number of randomly selected persons without such worry. Data on demographic characteristics, medical and psychiatric conditions, functional impairment, and health care utilization were collected. At least 1 month of worry was endorsed by 13.1% of the screened population. Correlates of worry included a cluster of psychiatric conditions (major depressive episode, panic attacks, and generalized anxiety disorder) and three clusters of physical conditions (heart disease, cancer, and other diseases). Worry about serious illness was associated with functional impairment and health care utilization.

Adolescent↗

fMRI biomarker of early neuronal dysfunction in presymptomatic Huntington's Disease.

BACKGROUND AND PURPOSE: Functional MR imaging (fMRI) has been used to probe basal ganglia function in people with presymptomatic Huntington's disease (pre-HD). A previous fMRI study in healthy individuals demonstrated activation of the basal ganglia during a time-discrimination task. The current study was designed to examine the relative sensitivity of fMRI compared with that of behavioral testing and morphometric measurements in detecting early neurodegenerative changes related to Huntington's disease (HD). METHODS: Pre-HD participants were assigned to two groups based on estimated years to diagnosis of manifest disease: close <12 years and far >or=12 years. Age at disease onset was estimated using a regression equation based on the number of trinucleotide CAG repeats. The time-discrimination task required participants to determine whether a specified interval was shorter or longer than a standard interval of 1200 milliseconds. RESULTS: Participants in the close group performed more poorly on the time-task discrimination than did control subjects; however, no differences were observed between far participants and control subjects. Similarly, close participants had reduced bilateral caudate volume relative to that of control subjects, whereas far participants did not. On functional imaging, close participants had significantly less activation in subcortical regions (caudate, thalamus) than control subjects; far participants had an intermediate degree of activation. In contrast, far participants had hyperactivation in medial hemispheric structures (anterior cingulate, pre-supplementary motor area) relative to close and control subjects. CONCLUSION: Hyperactivation of medial prefrontal regions compensated for reduced subcortical participation during time discrimination in pre-HD. This pattern of brain activation may represent an early neurobiologic marker of neuronal dysfunction.

Adult↗