Pain and pain tolerance in whiplash-associated disorders: A population-based study

Background

Pain is a cardinal symptom in individuals with whiplash‐associated disorders (WAD). We aimed to compare pain characteristics between individuals with WAD and individuals reporting chronic pain from other causes, and to determine whether potential differences were accounted for by experimental pain tolerance.

Methods

Data from the 6th Tromsø Study (2007–2008, n = 12,981) were analysed. The number of painful locations was compared between individuals with WAD and individuals reporting chronic pain from other causes using negative binomial regression, pain frequency using multinomial logistic regression and pain intensity using multiple linear regression. Differences in experimental pain tolerance (cold pressor test) were tested using Cox regression; one model compared individuals with WAD to those with chronic pain from other causes, one compared the two groups with chronic pain to individuals without chronic pain. Subsequently, regression models investigating clinical pain characteristics were adjusted for pain tolerance.

Results

Of individuals with WAD, 96% also reported other causes for pain. Individuals with WAD reported a higher number of painful locations [median (inter‐quartile range): 5 (3.5–7) vs. 3 (2–5), p < 0.001] and higher pain intensity (crude mean difference = 0.78, p < 0.001) than individuals with chronic pain from other causes. Pain tolerance did not differ between these two groups. Compared to individuals without chronic pain, individuals with WAD and individuals with chronic pain from other causes had reduced pain tolerance.

Conclusions

Individuals with WAD report more additional causes of pain, more painful locations and higher pain intensity than individuals with chronic pain from other causes. The increased pain reporting was not accounted for by pain tolerance.

Personality disorders, common mental disorders and receipt of disability benefits: evidence from the British National Survey of Psychiatric Morbidity

BACKGROUND

Common mental disorders (CMDs) are associated with occupational impairment and the receipt of disability benefits (DBs). Little is known about the relationship between personality disorders (PDs) and work disability, and whether the association between CMDs and work disability is affected by the presence of co-morbid PDs. The aim of this study was to examine the association between DB and individual categories of PDs, with special attention to the effect of co-morbid CMDs on this association.

METHOD

The association between DB and PD was examined using data from the 2000 British National Survey of Psychiatric Morbidity. Probable PD caseness was identified using the Structured Clinical Interview for DSM-IV Personality Disorders (SCID-II) screening questionnaire. The impact of CMDs, assessed with the revised version of the Clinical Interview Schedule (CIS-R), was examined as a covariate and in a stratified analysis of co-morbidity. Other covariates included sociodemographic factors, long-standing illnesses and substance use.

RESULTS

Probable PD was associated with DB, with the strongest associations found for borderline, dependent and schizotypal PD. Antisocial PD was not associated with DB. The relationship between PD and DB was strongly modified by CMD, reducing the association from an odds ratio (OR) of 2.84 to 1.34 [95% confidence interval (CI) 1.00-1.79)]. In the stratified analysis, co-morbid PD and CMD showed a stronger association with DB than PD without CMD but, when fully adjusted, this effect was not significantly different from the association between CMD without PD.

CONCLUSIONS

Individuals screening positive for PD are more likely to experience severe occupational outcomes, especially in the presence of co-morbid CMD.

Mental and personality disorders and abstinence from alcohol: results from a national household survey

BACKGROUND

The beneficial outcomes associated with moderate compared with low alcohol intake or abstinence may be due to the inclusion of people as 'low consumers', who have stopped consumption because of poor health. We investigated the association between alcohol abstinence and symptoms of common mental disorder and personality disorder, distinguishing between lifelong abstinence and abstinence following previous consumption.

METHOD

Analyses were based on the British National Survey of Psychiatric Morbidity 2000, which sampled 8580 residents aged 16-74 years. Hazardous drinking (Alcohol Use Disorders Identification Test) was excluded. Symptoms of common mental disorder (depression/anxiety) were identified by the Clinical Interview Schedule. The screening questionnaire of the Structured Clinical Interview for Axis II Personality Disorders was used to identify potential personality disorder. Self-reported alcohol abstinence was divided into lifelong abstinence and previous consumption. Previous consumers were asked why they had stopped. Covariates included socio-economic status, social activity and general health status.

RESULTS

After adjustment, alcohol abstinence was associated with both common mental disorder symptoms and any personality disorder, but only for previous consumers, in whom odds ratios were 1.69 (95% CI 1.23-2.32) and 1.45 (95% CI 1.09-1.94). Associations were non-specific, being apparent for most individual mental disorder symptoms and personality disorder categories. More detailed analysis indicated that associations were again limited to previous consumers who reported ceasing alcohol consumption for health reasons.

CONCLUSIONS

Worse mental health in low alcohol consumers, particularly those who have previously ceased for health reasons, should be taken into account when interpreting associations between moderate (compared with low) alcohol consumption and beneficial health outcomes.