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Biomedical subjects

R Michael Bagby

Publications and source records attributed to R Michael Bagby.

At least 19 recordsLinked to original sources
PubMed2006

The selective effect of antipsychotics on the different dimensions of the experience of psychosis in schizophrenia spectrum disorders.

While most standard symptom scales regard the 'psychotic' or 'positive' dimension of schizophrenia as a single factor, several lines of evidence suggest that psychosis itself is a multidimensional phenomenon. The foregoing literature suggested at least five distinct dimensions to psychosis; to test this, we developed, validated and applied an instrument to measure these dimensions and then applied it to examine the effect of antipsychotics on the different dimensions of the psychotic experience. The Dimensions of Psychosis Instrument (DIPI) was administered to 91 psychotic patients with schizophrenia spectrum disorders and a confirmatory factor analyses (CFA) was carried out to examine the five dimensions: cognitive preoccupation (CP) with the psychotic experience; emotional involvement (EM); behavioural impact (BI) of the experience; conviction (CO) in it; emotional; and external perspective (EP) about the experience. In a separate cohort of 17 prospectively treated patients, the impact of antipsychotics on these dimensions was assessed. BI showed the greatest improvement (32%) at 2 weeks, while CP and emotional improved somewhat less (22% and 14%, respectively). Improvement in CO was limited (6%) while EP showed no change. These results suggest that over the first few weeks of treatment, antipsychotics rapidly reduce the behavioural impact of the principal psychotic symptom and decrease cognitive and emotional preoccupation with it, without greatly altering the patients' conviction in or perspective about their psychotic experience.

Adolescent↗
PubMed2006

Depressive personality and dysthymia: evaluating symptom and syndrome overlap.

BACKGROUND: Depressive Personality (DP) is being evaluated for future inclusion in DSM. One recurring issue has been conceptual and empirical redundancy with Dysthymia (i.e., Dysthymic Disorder; DD). METHODS: The symptom and syndrome overlap of DP and DD were tested in a clinical sample (N = 125) using both self-report and clinician ratings. RESULTS: Confirmatory factor analyses of the DP and DD symptoms indicated that models which separate these two syndromes had a better fit than a model in which all symptoms were classified together, particularly for the clinician-rated data. At the same time, the syndromes were highly correlated. Binary diagnostic analysis showed that over 80% of the individuals meeting criteria for DP also met criteria for DD. As predicted, the best fit was obtained when the 'psychological' symptoms of DD-- low self-esteem and feelings of hopelessness-- were allowed to be part of both syndromes, and 82% of patients who met criteria for both DP and DD endorsed these two symptoms. LIMITATIONS: Clinical ratings rather than structured diagnostic interviews were used. As well, some models required modification to improve fit. CONCLUSIONS: Depressive personality traits can be empirically separated from DD symptoms, but including DP as a categorical diagnosis would lead to a high degree of diagnostic overlap. Much of this overlap is due to sharing psychological features in common. Revisions in the diagnostic system should find a way to incorporate depressive personality traits without insisting that they be diagnosed in a categorical manner.

Adult↗
PubMed2006

Attachment as moderator of treatment outcome in major depression: a randomized control trial of interpersonal psychotherapy versus cognitive behavior therapy.

Anxiety and avoidance dimensions of adult attachment insecurity were tested as moderators of treatment outcome for interpersonal psychotherapy (IPT) and cognitive- behavioral therapy (CBT). Fifty-six participants with major depression were randomly assigned to these treatment conditions. Beck Depression Inventory--II, Six-Item Hamilton Rating Scale for Depression scores, and remission status served as outcome measures. Patients higher on attachment avoidance showed significantly greater reduction in depression severity and greater likelihood of symptom remission with CBT as compared with IPT, even after controlling for obsessive-compulsive and avoidant personality disorder symptoms. Results were replicated across treatment completers and intent-to-treat samples. These results suggest that it is important to consider the interaction between attachment insecurity and treatment type when comparing efficacy of treatments.

Adult↗
PubMed2006

Assessing and interpreting personality change and continuity in patients treated for major depression.

Structural, mean- and individual-level, differential, and ipsative personality continuity were examined in 599 patients treated for major depression assigned to 1 of 6 forms of a 6-month pharmaco-psychotherapy program. Covariation among traits from the Five Factor model remained invariant across treatment, and patients described themselves as slightly more extraverted, open to experience, agreeable and conscientious, and substantially more emotional stable after treatment. Trait changes were only to a small extent explained by changes in depression severity. There was evidence for differential, individual-level, and ipsative stability, with stable personality profiles in terms of shape and to a lesser extent in terms of scatter and elevation. Traits remain relatively stable, except for emotional stability, despite the depressive state and the psychopharmacological interventions.

Adolescent↗
PubMed2006

The development of the Toronto Structured Interview for Alexithymia: item selection, factor structure, reliability and concurrent validity.

BACKGROUND: Assessments of personality constructs increasingly use self-report and structured interview instruments, which allow for a multimethod measurement approach and decrease specific measurement method bias. The aim of this study was to develop a valid and reliable structured interview for assessing the alexithymia construct. METHODS: Sixty interview questions were written initially, each with a set of scoring criteria and prompts and probes to elicit information assisting in the scoring of the respondents' answers. RESULTS: After pilot testing, the number of questions was reduced to 43, which were administered to 136 community participants and 97 psychiatric outpatients. A series of item and scale analyses further reduced the item pool to 24 items. Principal component analysis and confirmatory factor analysis of these 24 items revealed preliminary evidence of a hierarchical, four-factor structure, with four lower factors nested within two higher-order latent factors. This structural configuration resulted in the Toronto Structured Interview for Alexithymia (TSIA) with two domain scales and four facet scales. The TSIA and its six scales demonstrated acceptable levels of interrater, internal, and retest reliability. The TSIA and its scales correlated modestly but significantly with the 20-item Toronto Alexithymia Scale and its three factor scales, providing some support for the concurrent validity of this interview. CONCLUSION: The TSIA appears to be a promising structured interview for assessing alexithymia.

Adult↗
PubMed2006

Sexual function during bupropion or paroxetine treatment of major depressive disorder.

OBJECTIVE: The primary objective was to evaluate sexual function (SF) separately in men and women with major depressive disorder (MDD) before and during treatment with bupropion sustained release (SR) or paroxetine. The secondary objectives involved a comparative evaluation of the Sex Effects Scale (Sex FX) and the Investigator-Rated Sexual Desire and Functioning Scale (IRSD-F), as well as a comparison of antidepressant outcomes and an examination of the relation between level of depression and SF over time. METHOD: There were 141 patients (68 women and 73 men) who met DSM-IV criteria for a current major depressive episode. They were randomly assigned to receive bupropion SR (150 to 300 mg daily) or paroxetine (20 to 40 mg daily) under double-blind trial conditions. Patients were assessed at baseline and at 2, 4, 6, and 8 weeks with the 17-item Hamilton Depression Rating Scale (HDRS17), Sex FX, and IRSD-F. RESULTS: Prior to treatment, women reported significantly lower SF on both the Sex FX and IRSD-F scales, compared with men. During treatment, there were no significant drug differences on measures of SF over time for women; however, men who were treated with paroxetine reported a worsening of SF, whereas bupropion SR did not significantly alter SF. Both bupropion SR and paroxetine produced clinically and statistically significant reductions in HDRS17 scores as well as comparable rates of response and remission. There was a statistically significant correlation between the 2 measures of SF at all visits. There was also a significant inverse relation between depression and SF in women, but not in men, irrespective of drug. CONCLUSION: According to the Sex FX scale, a significant difference in antidepressant-related sexual dysfunction was detected in men, but not women, during treatment with bupropion SR or paroxetine.

Adolescent↗
PubMed2006

The incremental validity and clinical utility of the MMPI-2 infrequency posttraumatic stress disorder scale.

The incremental validity and clinical utility of the recently developed Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Infrequency Posttraumatic Stress Disorder Scale (Fptsd) was examined in relation to the family of MMPI-2 F scales in distinguishing feigned post-traumatic stress disorder (PTSD) from disability claimants with PTSD. Research participants instructed to feign PTSD when completing the MMPI-2 scored significantly higher on the MMPI-2 family of F scales and the Fptsd scale compared with their responses when completing the MMPI-2 under standard instructions and the sample of claimants with PTSD. Although comparable in magnitude, effect sizes derived from mean group differences and hierarchical logistic regressions for the Fptsd scale never exceeded those for F(B), and F(P), F, F(B), and F(P) added incrementally to Fptsd in the prediction of feigned PTSD. These results suggest that the Fptsd scale does not afford any incremental predictive utility for detecting feigned PTSD relative to the complement of the existing family of F scales.

Adult↗
PubMed2006

Development and validation of the Malingering Discriminant Function Index for the MMPI-2.

The predictive capacity of the MMPI-2 (Butcher et al., 2001) "fake-bad" validity scales (F, FB, and FP) is diminished when respondents have knowledge (i.e., coached) about the operating characteristics of these scales. In this investigation, we endeavored to develop a MMPI-2 fake bad validity index that would be less vulnerable to validity-scale knowledge. Applying discriminant function procedures, we derived a set of weighted Clinical and Content scales that reliably distinguished large samples of validity-scale coached undergraduate research participants instructed to feign mental illness (n = 534) from psychiatric patient samples (n = 590). We subsequently validated this Malingering Discriminant Function Index (M-DFI) in independent samples of research participants (n = 230) and patients (n = 300) and showed relatively less attenuation in predictive capacity compared with F, FB, and FP across uncoached and validity scale coached feigning conditions.

Adolescent↗
PubMed2005

Personality self-reports are concurrently reliable and valid during acute depressive episodes.

BACKGROUND: It is alleged that depression distorts the assessment of general personality traits. To test that hypothesis, we examined scores on the Revised NEO Personality Inventory (NEO-PI-R) administered to acutely depressed patients at baseline and 14 to 26 weeks after treatment with antidepressant medication. METHOD: Two hundred and fifty patients completed the NEO-PI-R at baseline, 109 patients after 14 to 26 weeks of antidepressant pharmacotherapy. 48 patients (49.5%) were identified as responders while 49 (50.5%) were identified as non-responders. The remaining 12 patients were excluded because they met HRSD response criteria but not the SCID-I MDD criteria at treatment completion. RESULTS: At baseline, NEO-PI-R scales showed high internal consistency and replicated the normative factor structure, suggesting that psychometric properties were preserved. Among non-responders, retest correlations were uniformly high (rs=.50 to .88) and mean levels showed little change, providing evidence for the consistency of personality self-reports during an acute depressive episode. NEO-PI-R scales showed construct validity in the concurrent prediction of a number of clinical criteria. Effective treatment had significant effects on the mean levels of neuroticism, which decreased, and extraversion, openness, and conscientiousness, which increased. LIMITATIONS: The participants were from a clinical database and were not randomly assigned for the treatment. CONCLUSIONS: The results suggest that the effect of acute depression is to amplify somewhat the personality profile of people prone to depression. Rather than regard these depression-caused changes in assessed personality trait levels as a distortion, we interpret them as accurate reflections of the current condition of the individual. Personality traits have biological bases, and when they are changed (by disease or therapeutic interventions) trait levels change.

Acute Disease↗
PubMed2005

A dimensional approach to personality in atypical depression.

The current study addresses the relationship of personality and atypical depression using the Five-Factor Model (FFM), a dimensional approach to personality. The aim of the study was to help clarify which personality traits are more characteristic of atypical depression than of other depressive subtypes. Outpatients (n=160) with non-psychotic major depression were characterized as having atypical (n=26), or non-atypical depression (n=134) based on DSM-IV criteria. To limit the effect of state depression, personality was assessed after subjects received a minimum of 14 weeks of antidepressant treatment. The Revised NEO Personality Inventory, which generates data based on the FFM, was the primary assessment measure. Post-treatment, relative to the non-atypical comparison group, the atypical group had significantly higher scores on the dimension of Neuroticism, the facets of Impulsivity and Anger-Hostility, and a significantly lower score on the facet of Deliberation. In sum, the FFM provides a new understanding of which unique personality characteristics may be associated with atypical depression.

Adult↗
PubMed2005

Usage and longitudinal effectiveness of a Web-based self-help cognitive behavioral therapy program for panic disorder.

BACKGROUND: Anxiety disorders are common problems that result in enormous suffering and economic costs. The efficacy of Web-based self-help approaches for anxiety disorders has been demonstrated in a number of controlled trials. However, there is little data regarding the patterns of use and effectiveness of freely available Web-based interventions outside the context of controlled trials. OBJECTIVE: To examine the use and longitudinal effectiveness of a freely available, 12-session, Web-based, cognitive behavioral therapy (CBT) program for panic disorder and agoraphobia. METHODS: Cumulative anonymous data were analyzed from 99695 users of the Panic Center. Usage statistics for the website were examined and a longitudinal survey of self-reported symptoms for people who registered for the CBT program was conducted. The primary outcome measures were self-reported panic-attack frequency and severity at the beginning of each session (sessions 2-12). RESULTS: Between September 1, 2002 and February 1, 2004, there were 484695 visits and 1148097 page views from 99695 users to the Panic Center. In that same time period, 1161 users registered for the CBT program. There was an extremely high attrition rate with only 12 (1.03%) out of 1161 of registered users completing the 12-week program. However, even for those who remained in the program less than 12 weeks we found statistically significant reductions (P<.002) in self-reported panic attack frequency and severity, comparing 2 weeks of data against data after 3, 6, or 8 weeks. For example, the 152 users completing only 3 sessions of the program reduced their average number of attacks per day from 1.03 (week 2) to 0.63 (week 3) (P<.001). CONCLUSIONS: Freely available Web-based self-help will likely be associated with high attrition. However, for the highly self-selected group who stayed in the program, significant improvements were observed.

Agoraphobia↗
PubMed2005

How antipsychotics work: the patients' perspective.

BACKGROUND: While much is known about the neuropharmacology and objective efficacy of antipsychotics, little is known about how these drugs act on psychosis from the patients' perspective. Most previous studies of the patient's perspective have focused on drug tolerability and acceptability-rather than their effects on psychosis per se. METHODS: The authors examined how antipsychotics work from a patient's perspective by analyzing their responses to a subjective questionnaire. Ninety-one patients with schizophrenia (cross-sectional component) and eight neuroleptic naïve patients (before and after treatment, longitudinal component) participated. The patients' responses to the questionnaire were analyzed using Principal Component Analysis (PCA) and general linear models. RESULTS: Analysis of the patients' responses showed that from their perspective the drugs were substantially more effective in: "help deal, help stop thinking, and make the symptoms not bother" rather than "take away" or "change my mind". This differentiation was clear in the raw data and was supported by a formal PCA. Two underlying factors-the first termed detachment and second eradication-explained 71% of the variance in the patients' perspective on how antipsychotics work for them. Neuroleptic naïve patients, who had no prior exposure, expected drugs to help with both detachment and eradication, but, changed their mind with just 6 weeks of experience with the medications. CONCLUSIONS: From the patients' perspective the action of antipsychotics is best characterized by a detachment from symptoms-rather than an eradication or elimination of symptoms. They have more wide-ranging expectations prior to antipsychotic exposure, but, even 6 weeks of exposure is sufficient to change their mind in favor of detachment. This finding is consistent with some of the very earliest ideas that antipsychotics produced a state of "indifference" and is also consistent with the more recent, neurobiologically informed notions that antipsychotics work by dampening the salience of psychotic symptoms.

Adolescent↗
PubMed2005

Socially desirable responding and the factorial stability of the NEO PI-R.

The goal of the present investigation is to compare the factor structure of the revised NEO Personality Inventory (NEO PI-R; P. T. Costa & R. R. McCrae, 1992) in samples of respondents differentially motivated to respond in a socially desirable manner. In the French sample, the authors compared the NEO PI-R structure of job applicants (N=12,631) subgrouped by relative degree of socially desirable responding with that of a normative sample (N=801). In the Belgian sample, the authors compared the NEO PI-R structure in naturally occurring groups, including job applicants (N=3,028), individuals receiving career counseling (N=221), and a normative sample (N=549). Results indicate that the NEO PI-R factor structure remained stable across all samples.

Belgium↗
PubMed2005

A comparison of the validity of the five-factor model (FFM) personality disorder prototypes. Using FFM self-report and interview measures.

Recent studies have demonstrated that personality disorders (PDs) can be assessed via a prototype-matching technique, which enables researchers and clinicians to match an individual's five-factor model (FFM) personality profile to an expert-generated prototype. The current study examined the relations between these prototype scores, using interview and self-report data, and PD symptoms in an outpatient sample (N = 115). Both sets of PD prototype scores demonstrated significant convergent validity with PD symptom counts, suggesting that the FFM PD prototype scores are appropriate for use with both sources of data.

Adult↗
PubMed2005

The impact of personality on symptom expression in obsessive-compulsive disorder.

Previous research conducted on the five-factor model of personality (FFM) in obsessive-compulsive disorder (OCD) has demonstrated that community and clinical participants score significantly higher than controls on the domains and facets of neuroticism and extraversion and selective facets of agreeableness and conscientiousness. However, studies have yet to examine the extent to which personality traits, as assessed by the FFM, are associated with the specific symptoms of OCD. The purpose of this study was to examine further the personality predictors of obsessive-compulsive symptoms in clinical participants using the facets of the FFM. Patients with a DSM-IV diagnosis of OCD (N = 56) completed the Revised NEO Personality Inventory, the Yale Brown Obsession Compulsion Scale, and the Beck Depression Inventory. Lower scores on openness to ideas were uniquely associated with greater obsession severity, whereas lower openness to actions was uniquely associated with greater compulsive severity. In contrast with past research that has emphasized the association between neuroticism and extraversion and dimensionally rated obsessive-compulsive symptoms, this study demonstrates the specific associations between selective facet traits of openness and clinical obsessions and compulsions. Whereas tendencies toward negative affectivity may confer a nonspecific vulnerability to the development of OCD, facets of openness may impact on the particular expression and severity of obsessive-compulsive symptoms.

Adult↗
PubMed2005

Predictors of professional and personal satisfaction with a career in psychiatry.

BACKGROUND: Many factors, including personal experience and personality traits, contribute to the emotional difficulties that psychiatrists experience in their professional work. The nature of the work itself also plays a significant role. OBJECTIVE: To determine those personal and professional characteristics that predict satisfaction with the practice of psychiatry. METHOD: We mailed a questionnaire that included items pertaining to aspects of personal and professional life to the entire population of psychiatrists in Ontario (N = 1574). RESULTS: Of the 1574, 52% (n = 802) responded. We conducted a series of regression analyses to determine factors related to career satisfaction or regret. A belief in the intrinsic value of psychiatry, a low perceived degree of emotional burden from patients, financial success, and satisfaction with psychotherapeutic work emerged consistently as significant predictors. A subsequent discriminant function analysis indicated that all 4 of these variables accurately predicted those psychiatrists with extreme satisfaction or dissatisfaction with work. CONCLUSIONS: These results reveal several variables associated with career satisfaction in the practice of psychiatry that might be useful to discuss with residents who are beginning their careers.

Career Choice↗
PubMed2005

Susceptibility of the MMPI-2 clinical, restructured clinical (RC), and content scales to overreporting and underreporting.

The authors examined and compared the susceptibility of three Minnesota Multiphasic Personality Inventory-2 (MMPI-2) scale sets (Clinical, Restructured Clinical [RC], and Content) to over- and underreporting using five analog samples. Two samples of 85 and 191 undergraduate students, respectively, took the MMPI-2 under underreporting versus standard instructions. Three samples consisting of 42 undergraduates, 73 psychiatric inpatients, and 84 medical patients took the MMPI-2 under overreporting versus standard instructions. A comparison of the effect sizes across the three sets of scales indicated that Clinical Scale scores are not less susceptible to distortion than the Content or RC Scales. An apparent lesser susceptibility to underreporting for the Clinical Scales was an artifact of the subtle items' effect on these scales.

Adult↗