Lynn Williams

A Taxometric Analysis of Type-D Personality

Objective: To test the dimensionality of Type-D personality, using taxometric procedures, to assess if Type-D personality is taxonic or dimensional. Type-D personality is treated as a categorical variable and caseness has been shown to be a risk factor for poor prognosis in coronary heart disease. However, at present, there is no direct evidence to support the assumption that Type D is categorical and able to differentiate true cases from noncases. Methods: In total, 1012 healthy young adults from across the United Kingdom and Ireland completed the DS14, the standard index of Type D, and scores were submitted to two taxometric procedures MAMBAC and MAXCOV. Results: Graphical representations (comparing actual with simulated data) and fit indices indicated that Type D is more accurately represented as a dimensional rather than categorical construct. Conclusion: Type D is better represented as a dimensional construct. Implications for theory development and clinical practice with respect to Type D are examined as well as the wider use of taxometrics within psychosomatic medicine (e.g., to investigate if there are medically unexplained syndrome taxons, such as a Gulf War Syndrome taxon). NA = negative affectivity; SI = social inhibition; MAMBAC = mean above minus below a cut; MAXCOV = maximum covariance; MAXEIG = maximum Eigenvalue; L-MODE = L-mode factor analysis; CCFI = curve comparison fit index.

Type D Personality Predicts Poor Medication Adherence in Myocardial Infarction Patients

Type D personality, the combination of negative affectivity (NA) and social inhibition (SI), is an emerging risk factor in cardiovascular disease. This study aimed to examine one possible behavioural mechanism to explain the link between Type D and ill-health. It was hypothesised that Type D personality would predict medication adherence in myocardial infarction (MI) patients. In a prospective study, 192 MI patients (54 females and 138 males) completed measures of Type D personality and provided demographic and medical information 1 week post-MI, and then 131 patients went on to complete a self-report measure of medication adherence 3 months post-MI. It was found that Type D personality predicts adherence to medication, after controlling for demographic and clinical risk factors. Critically, the constituent components of Type D, NA and SI, interact to predict medication adherence, after controlling for the effects of each component separately. Poor adherence to medication may represent one mechanism to explain why Type D cardiac patients experience poor clinical outcome, in comparison to non-Type D patients. Interventions, which target the self-management of medication, may be useful in these high-risk patients.

Type D personality and cardiac output in response to stress

Type D personality is predictive of adverse clinical outcome and psychological distress in cardiac patients. However, the mechanisms by which Type D affects health are largely unknown. This study (1) investigated the relationship between Type D and cardiovascular reactivity to experimentally induced stress and (2) tested the influence of Type D on subjective feelings of stress. Eighty four healthy young adults (50% males, mean (SD) age 22 (6.84) years), completed measures of Type D personality, stress arousal and a stress-inducing procedure involving a taxing mental arithmetic task. Cardiovascular measures were recorded throughout the experiment. Mixed measures ANOVA showed a significant main effect of Type D and a significant group by time effect of Type D on cardiac output in male participants. Type D males exhibit significantly higher cardiac output during the stressor phase compared to non-Type D males. However, there was no relationship between Type D and cardiovascular reactivity in females. In addition, Type D individuals exhibited significantly higher feelings of subjective stress compared to non-Type Ds. These findings provide new evidence on Type D and suggest that Type D may affect health through increased cardiac output and higher subjective feelings of stress following acute stress.

Type D personality is associated with maladaptive health-related behaviours.

Type D personality (the combination of negative affect and social inhibition) is associated with poor prognosis in cardiac patients. The current study aims to investigate the relationship between Type D and health-related behaviours. In a cross-sectional study, 200 healthy participants completed measures of Type D personality, and health-related behaviours. The results showed that Type D individuals engaged in more unhealthy behaviours including smoking, poor diet and lack of physical activity than non-Type D individuals. The association between Type D personality and maladaptive health behaviours may represent one mechanism to explain the link between Type D and ill-health.

Type D personality and illness perceptions in myocardial infarction patients

OBJECTIVES To determine the relationship between Type D personality (the tendency to experience negative emotions and to be socially inhibited) and illness beliefs in postmyocardial infarction (MI) patients. METHODS One hundred and ninety-two MI patients participated. Patients were assessed on demographic variables and completed the Type D Scale (DS14) and Brief Illness Perceptions Questionnaire one week post-MI. RESULTS Multivariate analysis of variance revealed that Type D patients were significantly different from non-Type D patients on every illness perception dimension. Type D patients believe that their illness has significantly more serious consequences (P<.001), will last significantly longer (P<.001), will be significantly less controllable by them (P<.05) or through treatment (P<.001) compared to non-Type D patients, and experience significantly more symptoms that they attribute to their illness (P<.001). In addition, they are significantly more concerned about their illness (P<.05), experience significantly more emotions as a result (P<.001), and find their illness to be significantly less comprehensible compared to non-Type D individuals (P<.001). CONCLUSION Type D individuals possess a distinct profile of illness beliefs, which may help explain the adverse effect of Type D on health outcomes following MI. Future research should evaluate intervention strategies to tackle illness perceptions in these high-risk patients.

Type D personality, physical symptoms and subjective stress: the mediating effects of coping and social support.

Coping style and social support may represent mechanisms to explain the relationship between Type D personality and ill-health. This study investigated whether Type D is associated with physical symptoms and perceived stress in a non-cardiac population, and if these relationships are mediated by coping and social support. In a cross-sectional study, 304 participants (110 males, mean age 22.1 years) completed measures of Type D, physical symptoms, coping, perceived stress and social support. Results showed that Type D, the interaction of negative affectivity and social inhibition (NA × SI), was positively correlated with physical symptoms, perceived stress, and avoidant coping, and negatively correlated with social support, problem-focused coping and emotion-focused coping. A series of bootstrapped multiple mediator tests showed that social support and avoidant coping fully mediated the relationship between Type D and physical symptoms. Furthermore, social support and emotion-focused coping partially mediated the relationship between Type D and perceived stress. These findings demonstrate for the first time that Type D personality is associated with physical symptoms in a non-cardiac population. Social support and coping style represent mechanisms that can, in part, explain the relationship between Type D and physical symptoms, and Type D and perceived stress.

Alexithymia and alcohol consumption: the mediating effects of drinking motives

The association between alexithymia and alcohol consumption has been well documented. However, little research has investigated the mechanisms behind the association. In the present study, the relationship between alexithymia, drinking motives and alcohol consumption was examined in a group of social (non-problem) drinkers. In a cross-sectional study, 862 participants completed the Toronto Alexithymia Scale, Drinking Motives Questionnaire, and provided alcohol consumption information. Regression analyses revealed that alexithymia predicts alcohol consumption. Formal mediation analyses demonstrated that this relationship was fully mediated by social, enhancement and coping drinking motives, and partially mediated by conformity. Drinking motives may represent one mechanism to explain the association between alexithymia and alcohol consumption.

Health behaviour mediates the relationship between type D personality and subjective health in the general population

Type D personality is associated with unhealthy behaviour and poor subjective health in the general population. This study investigated whether health behaviour mediates the relationship between Type D and subjective health. There were 217 participants who completed measures of Type D, health-related behaviour, physical symptoms and quality of life. Type D individuals reported significantly less healthy behaviour and significantly poorer subjective health than non-Type Ds. In addition, it was found that health behaviour partially mediates these relationships. The study demonstrates that health behaviour may partly explain the relationship between Type D and poor health outcomes.

Type D personality and three-month psychosocial outcomes among patients post-myocardial infarction

OBJECTIVE Type D personality has been proposed as a risk factor for poor prognosis in cardiac patients. Recent studies which have adopted a dimensional approach to Type D (negative affectivity×social inhibition) found no effect of Type D on mortality, after controlling for its constituent elements. To-date, no study has determined if Type D is associated with psychosocial outcomes in post-myocardial infarction (MI) patients when conceptualised as a dimensional variable. METHODS Participants were 192 MI patients (138 males, 54 females, mean age 66.0years) who provided demographic and clinical information, and completed measures of Type D one-week post-MI. Three months later, 131 of these MI patients completed measures of disability and quality of life. RESULTS Using regression analyses, adjusted for demographic and clinical data, Type D emerged as a significant predictor of disability and quality of life in MI patients, when analysed using the traditional categorical approach. However, Type D did not predict disability and quality of life when it was analysed using the interaction of negative affectivity and social inhibition. Negative affect emerged as a significant predictor of both disability (β=.433, t(130)=3.53, p<.01), and quality of life (β=-.624, t(130)=-5.68, p<.001). CONCLUSIONS The results suggest that Type D is not associated with short-term psychosocial outcome in MI patients, after controlling for its constituent elements. However, negative affect was significantly associated with both disability and quality of life. Future research should conceptualise Type D as the interaction between negative affectivity and social inhibition, rather than as a typology.

Type D personality and dietary intake: The mediating effects of coping style

This study aimed to investigate the relationship between Type D and dietary intake and to determine whether this relationship is mediated by coping. In a cross-sectional study, 187 healthy participants completed a self-report questionnaire measuring Type D personality, dietary intake and coping. Results showed that Type D was associated with maladaptive coping and significantly less healthy food intake, including more consumption of fat and sugar, and significantly less consumption of fruit and vegetables. Regression analyses showed that this relationship was partially mediated by coping. The results suggest that Type D personality may represent a risk factor for unhealthy eating.