Harold Merskey

Prospective study on the relationship between depressive symptoms and chronic musculoskeletal pain.

&NA; Chronic pain and depression often coexist, but there is still uncertainty about the nature of this relationship. Virtually all the available data are cross‐sectional and therefore do not clarify the causal relationship between the two variables. In epidemiological studies, chronic pain has often been defined fairly liberally in terms of the actual duration. In this study, the definition of chronic pain was based upon self‐reports of pain present for most of the days in at least 1 month of the 12 months preceding the interview. We tested the hypotheses that depression causes pain and that pain causes depression in a sample of 2324 subjects who were assessed for the presence of musculo‐skeletal pain and the presence of depression, using for the latter a standardized published instrument called the Center for Epidemiologic Studies Depression scale (CES‐D). The subjects were first examined using the National Health and Nutrition Survey (NHANES 1) of the United States National Center for Health Statistics from 1974 to 1975, and were followed‐up from 1981 to 1984. Those with data on both occasions represent 76% of an initial population of 3059 persons. On logistic regression analysis depressive symptoms at year 1 significantly predicted the development of chronic musculo‐skeletal pain at year 8 with an odds ratio of 2.14 for the depressed subjects compared with the non‐depressed subjects. In patients in whom pain was present at baseline no socio‐demographic variable alone predicted its persistence; however, male sex and white race together with 2 items of the CES‐D did predict the persistence of existing pain. On regression analysis for the prediction of depression, chronic pain was the most powerful variable; other factors which were significant include low education, living in rural areas or areas containing up to 250,000 inhabitants, being unemployed and female sex. The odds ratio for the prediction of depression by chronic pain was 2.85. Although a necessary connection has not been established between the predictive and outcome variables nevertheless the evidence supports both the views that depression promotes pain and pain promotes depression. The latter effect was somewhat more powerful than the former, but both only accounted for a small proportion of the variance.

Randomised trial of oral morphine for chronic non-cancer pain

BACKGROUND The use of opioid analgesics for chronic non-cancer pain is controversial. Some surveys report good pain relief and improvement in performance while others suggest a poor outcome with a propensity to psychological dependence or addiction. METHODS We undertook a randomised double-blind crossover study to test the hypothesis that oral morphine relieves pain and improves the quality of life in patients with chronic regional pain of soft tissue or musculoskeletal origin who have not responded to codeine, anti-inflammatory agents, and antidepressants. Morphine was administered as a sustained-release preparation in doses up to 60 mg twice daily and compared with benztropine (active placebo) in doses up to 1 mg twice daily over three-week titration, six-week evaluation, and two-week washout phases. Pain intensity, pain relief, and drug liking were rated weekly and psychological features, functional status, and cognition were assessed at baseline and at the end of each evaluation phase. FINDINGS After dose titration in the 46 patients who completed the study, the mean daily doses of drugs were morphine 83.5 mg and benztropine 1.7 mg. On visual analogue scales, the morphine group showed a reduction in pain intensity relative to placebo in period I (p = 0.01) and this group also fared better in a crossover analysis of the sum of pain intensity differences from baseline (p = 0.02). No other significant differences were detected. INTERPRETATION In patients with treatment-resistant chronic regional pain of soft-tissue or musculoskeletal origin, nine weeks of oral morphine in doses up to 120 mg daily may confer analgesic benefit with a low risk of addiction but is unlikely to yield psychological or functional improvement.

Chronic musculoskeletal pain and depressive symptoms in the national health and nutrition examination I. Epidemiologic follow-up study

&NA; We report here follow‐up data on subjects who were examined in two surveys conducted by the United States Center for Health Statistics at an interval of 8 years. The first survey was the 1st National Health and Nutrition Examination Survey (NHANES‐1), and the second conducted 8 years later was the National Health and Nutrition Epidemiologic Follow‐up Study (NHEFS). From an original sample of 3023 subjects, 153 were known to be deceased, leaving a potential sample of 2870 cases, of whom 2341 were ultimately examined in the NHEFS. The definition of pain used in the NHANES‐1 survey identified 15% of the subjects as suffering from persistent pain. Using a different pain definition, in the NHEFS, the frequency of subjects with chronic pain was 32.8%. Applying this second definition, the percentage of subjects with chronic pain in the NHANES‐1 had risen from 15 to 20.2. Some subjects (32.5%) who originally had chronic pain were free from pain at the time of follow‐up; 59% of the subjects with chronic pain on follow‐up did not have it initially. As found originally in the NHANES‐1, the group with chronic pain at the NHEFS comprised significantly more females, older people, and people with lower income. On logistic regression analysis the strongest relationship found at the NHEFS between the variables examined was between chronic pain and depression. Using a cut‐off point of ⩾ 20 on the Center for Epidemiologic Studies Depression scale (CESD), 16.4% of the subjects with chronic pain were depressed compared with 5.7% among those with no chronic pain (corrected odds ratio 3.26, confidence intervals 2.4–4.43).

Chronic musculoskeletal pain and depressive symptoms in the general population. An analysis of the 1st National Health and Nutrition Examination Survey data

&NA; Chronic pain and depression frequently occur together. A selection bias afflicts all hospital clinic and family practice populations in which this relationship has been examined. We report here some of the results from civilian populations outside institutions, examined in the United States in national surveys. The findings are based upon the recollection of individuals with respect to the period of 12 months prior to interview and upon the occurrence of depression in the previous week as indicated by the answers to the Depression Scale of the Centre for Epidemiologic Studies (CES‐D). They indicate that 14.4% of the United States population between the ages of 25–74 suffer from definite chronic pain related to the joints and musculoskeletal system. Another 7.4% have some pain of uncertain duration. Eighty‐three percent of the definite pain group received treatment. Chronic pain subjects scored significantly higher than normals on the CES‐D (10.68 ± S.E.M. 0.76 vs. 8.05 ± 0.23, P < 0.01) with subjects with pain of uncertain duration scoring similar to the definite chronic pain population (11.13 ± 0.76). Using a high cut‐off score for depression, 18% of the population with chronic pain were found to have depression. This is in contrast to 8% of the population who did not have chronic pain.

Fallacies in the pathological confirmation of the diagnosis of Alzheimer’s disease

OBJECTIVE Necropsy confirmed clinical diagnostic accuracy for Alzheimer’s disease is claimed to exceed 90%. This figure contains two fallacies; it includes cases in which Alzheimer’s disease exists with other diseases affecting cognition and the studies that report these figures excluded cases without necropsy (verification bias). The effect of these errors is estimated. METHODS Data were taken from the University of Western Ontario Dementia Study, a registry of dementia cases with clinical and psychometric follow up to necropsy based in a university memory disorders clinic with secondary and tertiary referrals. Data were available on 307 patients; 200 (65%) had clinically diagnosed Alzheimer’s disease, 12 (4%) vascular dementia, 47 (15%) mixed dementia, and 48 (16%) had other diagnoses. One hundred and ninety two of 307 cases (63%) died and 122 of 192 fatalities (64%) had necropsies. The pathological material was interpreted in two ways, allowing and disallowing coexistent disease in making a diagnosis of Alzheimer’s disease. In cases without necropsy, progressive cognitive loss was used as a marker for degenerative dementia. The outcome measures of interest were the positive predictive value of a clinical diagnosis of Alzheimer’s disease allowing and disallowing coexistent diseases and with and without correction for cases that were not necropsied. RESULTS The clinical diagnoses differed significantly between the population who died and those who did not. In cases without necropsy, 22% had no dementia on follow up, concentrated in early cases and men, showing considerable scope for verification bias. The positive predictive value of a diagnosis of Alzheimer’s disease was 81% including coexistent diseases, falling to 44% when limited to pure cases. Combined, these factors reduce the positive predictive value to 38% for pure Alzheimer’s disease. CONCLUSIONS Correction for dual pathology and verification bias halves the positive predictive value of the clinical diagnosis of Alzheimer’s disease. Data derived from necropsy studies cannot be extrapolated to the whole population. This has important implications including uncertainty about diagnosis and prognosis and a dilution effect in therapeutic trials in Alzheimer’s disease.

Emotional adjustment and chronic pain.

&NA; Previous work has suggested that patients with organic lesions causing pain may show as much emotional disturbance as patients with pain but without lesions. This study examined 141 chronic pain patients for their life experience, both currently and premorbidly, in terms of upbringing, neurotic traits and personality disturbance. Patients with an organic cause for pain reported significantly less family disturbance in childhood, less premorbid personality problems and less neurotic traits than patients who did not have any organic cause for their pain. The data provide support for the view that a significant proportion of the emotional disturbance associated with chronic pain is a secondary effect. Adjectives used to describe pain and factors causing exacerbation and relief of pain, although overlapping, also differed in the two groups.

The characteristics of persistent pain in psychological illness

Abstract Persistent pain is common amongst psychiatric patients, and occur in the older age group. Patients who deny the presence of any pain tend to be younger than the average for psychiatric patients. Whilst persistent pain occurs in several types of psychiatric illness, it shows a major association with neurosis (especially hysteria), and is relatively rare in schizophrenia and endogenous depression. Psychiatric patients with persistent pain generally descrive it as severe and usually experience it in more than one site, the commonest site being the head where 62% had some pain or ache, but any region may be involeve. 10% had some genital pain. Only a minority—some 13%—describe their pain in bizarre or “highly structured” terms. 38% gave an intermediate type of description, whilst 49% gave a simple description of their pain. For pains in psychiatric conditions general physical measures, including analgesics, were of little help, but there was often a relationship between pain and the emotional state. In accordance with this relationship relief was most frequently obtained by appropriate psychiatric treatment whether this was psychotherapeutic or physical.

Clinical and pathologic features of two groups of patients with dementia with Lewy bodies: effect of coexisting Alzheimer-type lesion load.

The objectives of this study were to examine the clinical and pathologic features of two subgroups of patients with dementia with Lewy bodies (DLB) differing in Alzheimer disease (AD)-type pathology load and to identify clinical variables useful in the differential diagnosis from AD. The records of 64 consecutive demented patients were reviewed. Pathologic diagnoses were independently established [35 AD cases, 11 cases of pure dementia with Lewy bodies (pDLB), and 18 cases of combined AD plus Lewy bodies (AD+LB)], and several neurodegenerative lesions were quantified. Clinical and pathologic data were compared between groups with univariate and multivariate analyses. Compared with the other groups, pDLB cases had more frequent acute-subacute onset of dementia [45% vs. AD (3%) and AD+LB (16%)], early parkinsonism [45% vs. AD (0%) and AD+LB (0%)], early [27% vs. AD (0%) and AD+LB (0%)] and late [73% vs. AD (11%) and AD+LB (16%)] hallucinations, fluctuating course [46% vs. AD (9%) and AD+LB (22%)], delusions [45% vs. AD (11%) and AD+LB (6%)], spontaneous parkinsonism [63% vs. AD (8%) and AD+LB (16%)], less frequent ideomotor apraxia and loss of insight, earlier urinary incontinence [3.2 ± 1.4 years after onset vs. AD (6.3 years) and AD+LB (5.8 years)], shorter duration of dementia [7.7 ± 2.4 years vs. AD (9.6 years) and AD+LB (11 years)], milder atrophy in computed tomography scans, greater brain weight, more transcortical spongiosis, wider cortex and subcortex, and less amyloid angiopathy. All pDLB cases but no AD cases had abnormal CA2 neurites. The clinical features of AD+LB patients were similar to those of AD patients other than more frequent acute-subacute onset and fluctuating evolution. Discriminant analyses selected four clinical variables differentiating pDLB from the other two groups as a whole: acute-subacute onset, early parkinsonism, early hallucinations, and early onset of urinary incontinence. Two or more of these features identified pDLB with a sensitivity of 81.8% and a specificity of 95.9%. Differentiation between the three groups (pDLB, AD+LB, and AD) or between both groups with LB (DLB) from AD could be only attained in 70% of cases. We conclude that early symptomatology is the main clue for the diagnosis of pDLB. We identified by discriminant analysis a set of clinical diagnostic criteria similar to those proposed by the Consortium on Dementia With Lewy Bodies. Accuracy was excellent for the diagnosis of pDLB but only mediocre for separating AD+LB as well as the entire DLB group from AD.

Suicidality in chronic abdominal pain: an analysis of the Hispanic Health and Nutrition Examination Survey (HHANES)

&NA; The objective of this study was to explore the relationship between suicidal ideation, suicidal attempts, depression and chronic abdominal pain in data gathered during a systematic epidemiologic survey, the Hispanic Health and Nutrition Examination Survey of the United States National Centre for Health Statistics. The material comprises data collected between 1982 and 1984 in samples of Hispanic groups in the United States. A sub‐sample which initially comprised 5498 subjects had provided answers to questions concerning the thoughts about death, wishes to die, thoughts of committing suicide and suicide attempts, as well as information about complaints of chronic abdominal pain and responses to the Centre for Epidemiologic Studies Depression Scale (CES‐D). Complete answers were available from 4964 subjects. The data were analyzed by tabulation, and logistic regression analyses. The lifetime prevalence of suicidality was much increased in subjects with pain compared with those without chronic abdominal pain. Rates for thoughts about death, wishing to die, suicidal ideation and suicide attempts were 2‐ to 3‐times more frequent in those with chronic abdominal pain compared with those without. Logistic regression analyses and the calculation of odds ratios confirmed that the most powerful predictive factors for suicidality were first, the presence of significant depressive ideation, and second, the presence of chronic abdominal pain. There is a strong relationship between chronic abdominal pain and suicidality in the Hispanic population in the United States. This was particularly evident in the Puerto Rican population of the United States where both rates were much increased compared with other Hispanic citizens. The present data are new, but no conclusion can be drawn concerning causality because they are cross‐sectional. They indicate the importance of the link between chronic abdominal pain and depression in this population.

The Persistence of Folly: A Critical Examination of Dissociative Identity Disorder. Part I. The Excesses of an Improbable Concept

Objective: To examine the concept of dissociative identity disorder (DID). Method: We reviewed the literature. Results: The literature shows that 1) there is no proof for the claim that DID results from childhood trauma; 2) the condition cannot be reliably diagnosed; 3) contrary to theory, DID cases in children are almost never reported; and 4) consistent evidence of blatant iatrogenesis appears in the practices of some of the disorders proponents. Conclusions: DID is best understood as a culture-bound and often iatrogenic condition.