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Biomedical subjects

L A Clark

Publications and source records attributed to L A Clark.

At least 37 records · Page 2Linked to original sources
PubMed1997

Measurement and mismeasurement of mood: recurrent and emergent issues.

The affective explosion in psychology has led to tremendous advances in mood measurement. Mood ratings reflect a hierarchical structure consisting of two broad dimensions-Positive Affect and Negative Affect-and multiple specific states. Brief scales have been developed that reliably assess Positive and Negative Affect across different populations and time frames, in both between- and within-subject data. We examine controversies related to (a) the content of these higher order scales and (b) the independence of Positive and Negative Affect. Regarding the latter, we show that Positive and Negative Affect scales remain largely independent across a wide range of conditions, even after controlling for random and systematic error. Finally, there remains little consensus regarding the lower order structure of affect. This lack of a compelling taxonomy has substantially slowed progress in assessing mood at the specific affect level.

Journal Article↗
PubMed1997

Personality disorder assessment: the challenge of construct validity.

We begin with a review of the data that challenge the current categorical system for classifying personality disorder, focusing on the central assessment issues of convergent and discriminant validity. These data indicate that while there is room for improvement in assessment, even greater change is needed in conceptualization than in instrumentation. Accordingly, we then refocus the categorical-dimensional debate in assessment terms, and place it in the broader context of such issues as the hierarchical structure of personality, overlap and distinctions between normal and abnormal personality, sources of information in personality disorder assessment, and overlap and discrimination of trait and state assessment. We conclude that more complex conceptual models that can incorporate both biological and environmental influences on the development of adaptive and maladaptive personality are needed.

Humans↗
PubMed1995

Testing a tripartite model: II. Exploring the symptom structure of anxiety and depression in student, adult, and patient samples.

L. A. Clark and D. Watson (1991) proposed a tripartite model of depression and anxiety that divides symptoms into 3 groups: symptoms of general distress that are largely nonspecific, manifestations of anhedonia and low positive affect that are specific to depression, and symptoms of somatic arousal that are relatively unique to anxiety. This model was tested by conducting separate factor analyses of the 90 items in the Mood and Anxiety Symptom Questionnaire (D. Watson & L. A. Clark, 1991) in 5 samples (3 student, 1 adult, 1 patient). The same 3 factors (General Distress, Anhedonia vs. Positive Affect, Somatic Anxiety) emerged in each data set, suggesting that the symptom structure in this domain is highly convergent across diverse samples. Moreover, these factors broadly corresponded to the symptom groups proposed by the tripartite model. Inspection of the individual item loadings suggested some refinements to the model.

Adult↗
PubMed1995

Testing a tripartite model: I. Evaluating the convergent and discriminant validity of anxiety and depression symptom scales.

L.A. Clark and D. Watson (1991) proposed a tripartite model that groups symptoms of depression and anxiety into 3 subtypes: symptoms of general distress that are largely nonspecific, manifestations of somatic tension and arousal that are relatively unique to anxiety, and symptoms of anhedonia and low Positive Affect that are specific to depression. This model was tested in 5 samples (3 student, 1 adult, and 1 patient sample) using the Mood and Anxiety Symptom Questionnaire (MASQ; D. Watson & L. A. Clark, 1991), which was designed to assess the hypothesized symptom groups, together with other symptom and cognition measures. Consistent with the tripartite model, the MASQ Anxious Arousal and Anhedonic Depression scales both differentiated anxiety and depression well and also showed excellent convergent validity. Thus, differentiation of these constructs can be improved by focusing on symptoms that are relatively unique to each.

Adult↗
PubMed1994

Temperament, personality, and the mood and anxiety disorders.

Literature on temperament, personality, and mood and anxiety disorders is reviewed. The review is organized primarily around L. A. Clark and D. Watson's (1991b) tripartite model for these disorders, but other influential approaches are also examined. Negative affectivity (or neuroticism) appears to be a vulnerability factor for the development of anxiety and depression, indicates poor prognosis, and is itself affected by the experience of disorder. Positive affectivity (or extraversion) is related more specifically to depression, may be a risk factor for its development, suggests poor prognosis, and also may be affected by the experience of disorder. Other personality dimensions (e.g., anxiety sensitivity, attributional style, sociotropy or dependence, autonomy or self-criticism, and constraint) may constitute specific vulnerability factors for particular disorders. More longitudinal and measurement-based research that jointly examines anxiety and depression is needed.

Anxiety Disorders↗
PubMed1994

Structures of personality and their relevance to psychopathology.

Trait concepts are used extensively in psychopathology research, but much of this research has failed to consider recent advances in the dimensional structure of personality. Many investigators have discounted the importance of this structural research, arguing that (a) little progress has been made in this area, (b) structural models have little direct relevance for psychopathology research, and (c) the principal methodological tool of structural research--factor analysis--is too subjective to yield psychologically meaningful results. We dispute each of these objections. Specifically, we offer an integrative hierarchical model--composed of four higher order traits--that is congruent with each of the major structural subtraditions within personality. We also discuss the implications of this integrative scheme for basic trait research, for the conceptualization and assessment of psychopathology, and for the etiology of disorder.

Factor Analysis, Statistical↗
PubMed1992

Determination of the anticonvulsant felbamate in beagle dog plasma by high-performance liquid chromatography.

An automated internal standard method for the determination of felbamate in 0.1 ml of plasma from pediatric and adult beagle dogs was developed. Plasma proteins are precipitated with acetonitrile and after centrifugation the supernatant is directly injected on a Spherisorb ODS2, 3 microns, 150 mm x 4.6 mm I.D. column with 25% acetonitrile in aqueous phosphate buffer, pH 6.50, as mobile phase with ultraviolet detection at 210 nm. The run time is 10 min, the linear range is 0.150-150 micrograms/ml felbamate, and the lower limit of quantitation is 0.150 microgram/ml.

Animals↗
PubMed1992

Affect, personality, and social activity.

These studies examined relations between social activity and state and trait measures of Positive and Negative Affect. In Study 1 Ss completed scales relevant to 3-factor models of personality and a weekly mood and social activity questionnaire for 13 weeks. In Study 2 Ss completed measures of the 5-factor model of personality and a daily mood and social activity survey for 6-7 weeks. In within- and between-Ss analyses, socializing correlated significantly with state measures of Positive Affect and with trait measures of Extraversion/Positive Emotionality. These relations were relatively general across various types of positive affect and social events; however, specific types of social events also were differentially related to affect. In contrast, social activity had no consistent association with measures of Negative Affect or the other personality dimensions. The results support a temperamental view of Extraversion.

Adult↗
PubMed1992

On traits and temperament: general and specific factors of emotional experience and their relation to the five-factor model.

In this article we investigate relations between general and specific measures of self-rated affect and markers of Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness. Replicating previous research, we found strong and pervasive associations between Neuroticism, its facets, and the various negative affects; and between Extraversion, its facets, and the positive affects. Conscientiousness also had a significant, independent relation with general positive affect, but this effect was entirely due to the specific affect of attentiveness, which was more strongly related to Conscientiousness than Extraversion. Conversely, only the achievement facet of Conscientiousness correlated broadly with the positive affects. Finally, hostility had a strong independent association with (low) Agreeableness. The results for Neuroticism and Extraversion further clarify the temperamental basis of these higher order trait dimensions; whereas those obtained for Agreeableness and Conscientiousness illustrate the importance of examining personality-affect relations at the lower order level.

Adult↗
PubMed1991

Tripartite model of anxiety and depression: psychometric evidence and taxonomic implications.

We review psychometric and other evidence relevant to mixed anxiety-depression. Properties of anxiety and depression measures, including the convergent and discriminant validity of self- and clinical ratings, and interrater reliability, are examined in patient and normal samples. Results suggest that anxiety and depression can be reliably and validly assessed; moreover, although these disorders share a substantial component of general affective distress, they can be differentiated on the basis of factors specific to each syndrome. We also review evidence for these specific factors, examining the influence of context and scale content on ratings, factor analytic studies, and the role of low positive affect in depression. With these data, we argue for a tripartite structure consisting of general distress, physiological hyperarousal (specific anxiety), and anhedonia (specific depression), and we propose a diagnosis of mixed anxiety-depression.

Anxiety Disorders↗
PubMed1988

Mood and the mundane: relations between daily life events and self-reported mood.

Daily mood ratings and corresponding diary entries were studied to determine relations between common events and two independent mood factors--Positive Affect (PA) and Negative Affect (NA)--in a sample of 18 young adults over a 3-month period. In an extension of findings from earlier interindividual studies, PA (enthusiastic, delighted vs. sluggish, drowsy) was found to be associated with a wide range of daily events, whereas fewer correlations were found between these events and NA (distressed, nervous, angry vs. calm, relaxed). The relation between high PA and reported social interactions (particularly physically active social events) was especially robust, and its effects were noted repeatedly; NA was unrelated to social activity. As hypothesized, high NA was associated with physical problems; contrary to expectations, low PA also tended to be correlated with health complaints. Overall, the results reaffirm the importance of assessing NA and PA independently and suggest that PA is an interesting and important dimension that deserves more research attention. Theoretical considerations and clinical implications are discussed.

Adaptation, Psychological↗
PubMed1988

Development and validation of brief measures of positive and negative affect: the PANAS scales.

In recent studies of the structure of affect, positive and negative affect have consistently emerged as two dominant and relatively independent dimensions. A number of mood scales have been created to measure these factors; however, many existing measures are inadequate, showing low reliability or poor convergent or discriminant validity. To fill the need for reliable and valid Positive Affect and Negative Affect scales that are also brief and easy to administer, we developed two 10-item mood scales that comprise the Positive and Negative Affect Schedule (PANAS). The scales are shown to be highly internally consistent, largely uncorrelated, and stable at appropriate levels over a 2-month time period. Normative data and factorial and external evidence of convergent and discriminant validity for the scales are also presented.

Arousal↗
PubMed1987

A quantitative analysis of the effects of activity and time of day on the diurnal variations of blood pressure.

The effects of activity and time of day on blood pressure (BP) were analyzed in 461 patients with untreated hypertension who wore a noninvasive portable BP recorder which took readings every 15 minutes for 24 hours. Patients recorded activity and location in a diary. The data were analyzed separately for two groups of patients: the 190 who stayed at home and the 271 who went to work. The effects of 16 different activities on BP were estimated by relating the BP to the associated activity and to the individual's clinic BP. Blood pressure was higher at work than at home, but the increment of BP for individual activities was similar in the two locations. The overall effect of activities on BP variability was computed using a one-way analysis of covariance model. For the patients who went to work this model accounted for 40% of the observed variation (R2) for systolic and 39% for diastolic BP. A similar model using time of day instead of activity accounted for 33% of variability in both systolic and diastolic BP. Combining activity and time of day was little better than activity alone (41% for both). After allowing for the effects of activity on BP, where sleep is one of the activities, there was no significant diurnal variation of BP. We conclude that there is no important circadian rhythm of BP which is independent of activity.

Adolescent↗