Ronald R. Holden

Nortriptyline and gabapentin, alone and in combination for neuropathic pain: a double-blind, randomised controlled crossover trial

BACKGROUND Drugs for neuropathic pain have incomplete efficacy and dose-limiting side-effects when given as monotherapy. We assessed the efficacy and tolerability of combined nortriptyline and gabapentin compared with each drug given alone. METHODS In this double-blind, double-dummy, crossover trial, patients with diabetic polyneuropathy or postherpetic neuralgia, and who had a daily pain score of at least 4 (scale 0-10), were enrolled and treated at one study site in Canada between Nov 5, 2004, and Dec 13, 2007. 56 patients were randomised in a 1:1:1 ratio with a balanced Latin square design to receive one of three sequences of daily oral gabapentin, nortriptyline, and their combination. In sequence, a different drug was given to each randomised group in three treatment periods. During each 6-week treatment period, drug doses were titrated towards maximum tolerated dose. The primary outcome was mean daily pain at maximum tolerated dose. Analysis was by intention to treat. This trial is registered, number ISRCTN73178636. FINDINGS 45 patients completed all three treatment periods; 47 patients completed at least two treatment periods and were analysed for the primary outcome. Mean daily pain (0-10; numerical rating scale) was 5.4 (95% CI 5.0 to 5.8) at baseline, and at maximum tolerated dose, pain was 3.2 (2.5 to 3.8) for gabapentin, 2.9 (2.4 to 3.4) for nortriptyline, and 2.3 (1.8 to 2.8) for combination treatment. Pain with combination treatment was significantly lower than with gabapentin (-0.9, 95% CI -1.4 to -0.3, p=0.001) or nortriptyline alone (-0.6, 95% CI -1.1 to -0.1, p=0.02). At maximum tolerated dose, the most common adverse event was dry mouth, which was significantly less frequent in patients on gabapentin than on nortriptyline (p<0.0001) or combination treatment (p<0.0001). No serious adverse events were recorded for any patients during the trial. INTERPRETATION Combined gabapentin and nortriptyline seems to be more efficacious than either drug given alone for neuropathic pain, therefore we recommend use of this combination in patients who show a partial response to either drug given alone and seek additional pain relief. Future trials should compare other combinations to their respective monotherapies for treatment of such pain. FUNDING Canadian Institutes of Health Research.

Three common social desirability scales: Friends, acquaintances, or strangers?

Abstract The underlying factor structure of three commonly used social desirability scales was investigated using the item responses of 402 university undergraduates. Analyses indicated that the three scales constructed by Jackson, by Edwards, and by Crowne and Marlow did not show strong convergence in their latent structures. Two higher order social desirability dimensions emerged: a Sence of Own General Capability defined by items from the Jackson scale and the Edwards scale, and Interpersonal Sensitivity based on items from the Crowne and Marlowe scale. It was concluded that not all social desirability scales are interchangeable and that test developers should take into account both dimensions of social desirability when constructing or evaluating psychological measures.

A model of personality test item response dissimulation

A general model of faking on self-report personality test items is proposed and empirically evaluated. The model predicts that differential test item response latencies should be faster for schema-congruent test answers than for noncongruent responses. Thus, individuals faking good should take relatively longer to endorse socially undesirable test item content than desirable test item content. Conversely, individuals faking bad should endorse socially desirable test item content relatively slower than undesirable test item content

Test-retest reliability of the Hopelessness Scale and its items in a university population.

In a study that used 149 university undergraduates and a 3-week test-retest interval, the stability of the Hopelessness Scale was examined. Scale scores and item responses demonstrated high test-retest reliabilities. Additional analyses indicated significant sex differences on the Hopelessness Scale. It was concluded that the Hopelessness Scales stability fulfills a prerequisite for it to be a predictor of long-term suicidal risk.

The NEO five-factor inventory in a Canadian context: Psychometric properties for a sample of university women

Abstract The psychometric characteristics of the NEO Five-Factor Inventory (NEO-FFI) were examined with a sample of 243 Canadian university women. Results indicated that although all five NEO-FFI scales possessed adequate levels of internal consistency, scores on scales of Extraversion and Agreeableness were negatively skewed, and mean scores on four of the five scales differed significantly from the female college norms reported in the tests manual. Factor analyses of the NEO-FFI test items generally supported the scoring key of the test, although five items appeared problematic. Overall, subject to appropriate cautions, continued use of the NEO-FFI is supported psychometrically.

Structured personality test item characteristics and validity

Abstract Using the structured personality test item as the unit of analysis, the purpose of this research was to evaluate the relationship between validity and a variety of other test item parameters. Of particular interest was the relationship of test item criterion validity to negative keying and to negative wording. By drawing a distinction between negative keying and negative wording it was demonstrated that the use of balanced scales to control acquiescence need not result in a reduction in item criterion validity. Whereas the use of negative wording has in the past reduced validity, data demonstrated that positively worded, negatively keyed items did not. In addition, results indicated that clear, moderately short, relevant test items tended to be the most empirically valid.

The construct of alexithymia: associations with defense mechanisms

Alexithymia is a dimensional personality construct that encompasses a cluster of cognitive and affective characteristics relating to difficulty identifying and describing feelings, limited imaginal capacity, and having an externally oriented thinking style. Attempts to explain the etiology of high levels of alexithymia have resulted in disagreements regarding the relationship between alexithymia and psychological defense mechanisms. Much of the previous research suggests strong associations between alexithymia and immature or maladaptive defense styles. To examine these relationships using correlations, multiple regression and factor analytic techniques, three nonclinical populations in Australia and Canada were studied with a view to evaluating the association of defense mechanisms and response styles with alexithymia. Our results support the association of alexithymia with emotional inhibition, but extend those associations to immature defense styles and aspects of social desirability.

Psychache as a Mediator in the Relationship between Perfectionism and Suicidality.

E. S. Shneidman (1993) has proposed that psychache (i.e., unbearable psychological pain) is directly associated with suicide and mediates the effects of all other relevant psychological factors. The present research tested this proposition by examining whether psychache mediates the relationship between perfectionism and suicidality. Furthermore, the link between perfectionism and psychache was examined for mediation by unfulfilled psychological needs. Participants were 264 undergraduate students. Structural equation modeling with bootstrapped estimates determined that psychache fully mediated the relationship between socially prescribed perfectionism and suicidality. Additionally, the relationship between socially prescribed perfectionism and psychache was partially mediated by unfulfilled psychological needs.

A confirmatory evaluation of the profile of mood states: Convergent and discriminant item validity

The Profile of Mood States was administered to samples of 182 college males, 179 college females, and 257 prison inmates. College males and females did not differ significantly from each other in terms of scale elevation but differed from prison inmates on all scales except Fatigue-Inertia. The college samples differed from the published normative college samples, suggesting the importance of using local norms. A confirmatory item factor analysis suggested convergent item validity with the scoring key and similarity of structure across samples. Discriminant item validity, however, suggested that a smaller number of mood scales would offer a more justifiable interpretation of this inventory.

Suicide, hopelessness, and social desirability: a test of an interactive model

We examined the relationships among suicidal indices, hopelessness, and social desirability. Both hopelessness and a measure of social desirability that reflected a sense of general capability were significant indicators of suicidal manifestations. In particular, hierarchical multiple regression procedures demonstrated that hopelessness and social desirability interacted in the prediction of suicide variables. Results generalized across various clinical diagnostic subgroups of psychiatric patients and a sample of prisoners and across different clinically evaluated and self-reported indices of suicidal behavior. Findings are interpreted to mean that a sense of general capability buffers the link of hopelessness to suicidal behavior. Implications for understanding the cognitions associated with suicide and for improving prediction of persons at risk are discussed.