Comorbidity of substance use disorders with mood and anxiety disorders: results of the International Consortium in Psychiatric Epidemiology

This article reports the results of a cross-national investigation of patterns of comorbidity between substance use and psychiatric disorders in six studies participating in the International Consortium in Psychiatric Epidemiology. In general, there was a strong association between mood and anxiety disorders as well as conduct and antisocial personality disorder with substance disorders at all sites. The results also suggest that there is a continuum in the magnitude of comorbidity as a function of the spectrum of substance use category (use, problems, dependence), as well as a direct relationship between the number of comorbid disorders and increasing levels of severity of substance use disorders (which was particularly pronounced for drugs). Finally, whereas there was no specific temporal pattern of onset for mood disorders in relation to substance disorders, the onset of anxiety disorders was more likely to precede that of substance disorders in all countries. These results illustrate the contribution of cross-national data to understanding the patterns and risk factors for psychopathology and substance use disorders.

The incidence and outcome of subclinical psychotic experiences in the general population

OBJECTIVES

To examine the incidence and 2-year stability and outcome of subclinical psychotic experiences in the general population.

DESIGN

The Netherlands Mental Health Survey and Incidence Study (NEMESIS), a longitudinal general population study.

METHODS

A representative population sample of 7,076 participants was interviewed with the composite international diagnostic interview at baseline, 1 year later at T(1) and again 2 years later at T(2). A sample of individuals was identified who had onset of a new, broadly defined psychotic experience between baseline and T(1) (N = 79; incidence = 2%). Stability and outcome of these incident positive psychotic experiences was reassessed by interview at T(2), at which 25 individuals had a CIDI rating of broadly defined psychotic experience (subclinical outcome) and 11 individuals had psychotic experiences with functional impairment and need for care (clinical outcome).

RESULTS

The majority of individuals with an incident psychotic experience did not display persistence of the experience. Only 8% of individuals with a T1 incident psychotic experience had evidence of a T2 subclinical outcome, and only 8% had evidence of a T2 clinical outcome. The emotional context and the number of the T1 incident psychotic experiences were strong modifiers of predictive power for the clinical outcome, but not (or to a much lesser extent) for the subclinical outcome.

CONCLUSIONS

The incidence of positive psychotic experiences in the general population is around 100 times greater than traditional estimates of incidence of psychotic disorder such as schizophrenia. The far most likely outcome for these experiences is discontinuity. For the small proportion who display continuity, there is an equally large likelihood of subclinical and clinical 2-year outcomes. Emotional appraisal and degree of intrusiveness of psychotic experiences are important modifiers not for continuity per se but for clinical outcome specifically.

Prevalence and age of onset for drug use in seven international sites: results from the international consortium of psychiatric epidemiology

This study compares lifetime prevalence and age of first use (onset) for alcohol, cannabis, and other drugs in six international sites. Data from seven epidemiologic field surveys that used compatible instruments and study designs were compiled for cross-site analyses by the International Consortium of Psychiatric Epidemiology (ICPE). The world health organization's composite international diagnostic instrument (WHO-CIDI) and additional items were used to ascertain drug use in each site. Lifetime use rates were estimated for alcohol, cannabis, and other illicit drugs. Survival analyses were used to estimate age of onset. Study settings and main results: use of alcohol twelve or more times ranged in descending order from the Netherlands (86.3%), United States (71.7%), Ontario, Canada (71.6%); São Paulo, Brazil (66.1%), Munich, Germany (64.9%), Fresno, California (USA) (51.9%), to Mexico City (43.2%). Use of cannabis five or more times in a lifetime ranged from 28.8 in the United States to 1.7% in Mexico City, and other drugs ranged from United States (19.4%) to Mexico City (1.7%). Age of first use was similar across study sites. This study demonstrates the fundamental uniformity of onset patterns by age as contrasted with wide variations in lifetime prevalences across sites. Study findings suggest that drug use patterns may change among emigrating populations from low consumption nations as a consequence of international resettlement in nations with higher rates. Methodological limitations of the study along with recommendations for future international comparative research are discussed.

Bipolar disorder in the general population in The Netherlands (prevalence, consequences and care utilisation): results from The Netherlands Mental Health Survey and Incidence Study (NEMESIS)

BACKGROUND

Little is known about the prevalence of bipolar disorder in the general population, what proportion is receiving care and what factors motivate people to seek help.

METHOD

Data were derived from The Netherlands Mental Health Survey and Incidence Study (NEMESIS), a psychiatric epidemiological study in the general population in The Netherlands. DSM-III-R diagnoses were based on the Composite International Diagnostic Interview (CIDI).

RESULTS

Lifetime prevalence of bipolar disorder was 1.9%. Compared to other mental disorders, people with bipolar disorder were more often incapacitated were more likely to have attempted suicide and reported a poorer quality of life 82.8% had experienced an additional mental disorder in their lifetime; 25.5% had never sought help for their emotional problems, not even primary, informal or alternative care.

LIMITATIONS

Three limitations of the study are: (1) the CIDI prevalence estimates for bipolar disorder may be inflated; (2) personality disorders were not recorded in the NEMESIS dataset; (3) in NEMESIS certain groups have not been reached.

CONCLUSION

Three-quarters of the bipolar respondents do not benefit sufficiently from the treatment methods now available. In view of the serious consequences of this condition, greater efforts are needed to reach people with bipolar disorder, to get them into treatment.

When does experience of psychosis result in a need for care? A prospective general population study

Not all individuals with experience of psychosis develop a need for care. The present study investigated differences in coping strategies and associated levels of perceived control over psychotic symptoms, in relation to need for care status. The influence of coping on need for care was assessed in 47 individuals incident for psychosis in a general population sample of 4,722. Need for care was associated with severity of psychotic experiences rather than associated distress, mean level of control, or average number of coping strategies used. Qualitative differences were apparent, however, in that those who resorted to the strategy of symptomatic coping (a coping strategy characterized by going along with and indulging in symptoms) experienced less control over their symptoms (odds ratio [OR] = 0.79, 95% confidence interval [CI]: 0.63-0.98) and had a higher probability of need for care (OR = 6.07, 95% CI: 1.94-18.95). The results suggest that qualitative differences in self-initiated coping modify the risk for need for care and subsequent patient status in those who experience psychotic symptoms and point to the possible importance of early coping-based interventions.

Neuroticism, a central link between somatic and psychiatric morbidity: path analysis of prospective data

BACKGROUND

Neuroticism and somatic complaints are linked, and the aim of this study is to disentangle which mechanisms may be responsible for this association.

METHOD

In a stratified sample of 7076 adults (18-65 years), neuroticism, 22 self-reported chronic somatic conditions and five broad CIDI-diagnosed psychiatric syndromes were assessed at baseline and, in 3625 (51%) subjects, 3 years later. Using path analysis we examined whether neuroticism has direct links with future somatic morbidity and, conversely, whether morbidity at baseline is linked with higher neuroticism later on.

RESULTS

Neuroticism at baseline is associated with psychiatric and somatic morbidity at follow-up after 3 years (31% and 24%, respectively, are direct associations, i.e. unmediated by each other or neuroticism at follow-up and independent of morbidity at baseline). Conversely, somatic and psychiatric morbidity at baseline are associated with increased neuroticism at follow-up (27% and 15%, respectively, are direct associations).

CONCLUSIONS

Neuroticism raises risk for psychiatric and somatic morbidity but also results from them. It represents a central nexus in the process of morbidity accumulation.

Establishing a set of mental health indicators for Europe

AIMS

This review presents the background work for developing a set of mental health indicators as part of a comprehensive health monitoring system in the European Union. The review focuses on the appraisal of mental health at population level with special emphasis on assessments that could be useful for mental health promotion.

METHODS

A functional model of mental health is used to delineate variables important for a set of mental health indicators. Variables that are not possible to monitor at population level are not discussed here. Literature searches were conducted through the MEDLINE, PSYCHLIT, and SOCIOLOGICAL ABSTRACTS databases and available textbooks.

RESULTS

The review presents findings from research seeking associations between mental health and ill health and different individual, social, economic, ecological, and service-related characteristics. Specific domains as key starting points in establishing a set of mental health indicators are outlined according to the research findings.

CONCLUSION

A set of mental health indicators can enhance the visibility of mental health issues in the European context. Ultimately the indicators could be used in estimating how the targets set for health policies are met, and whether there has been a measurable decrease in disability, suffering, and disease.

Combined effect of mental disorder and low social support on care service use for mental health problems in the Dutch general population

BACKGROUND

People with a mental disorder have high rates of service utilization for emotional or addiction problems. Little is known about the role of functional impairments and low social support in such service use. This article investigates: (1) whether the presence of multiple functional impairments mediates the link between mental disorder and service use; and (2) whether social support modifies that association.

METHODS

Data were derived from the Netherlands Mental Health Survey and Incidence Study, NEMESIS, a prospective general population study. Predictors of service use (mental disorder; functional impairments; social support) were recorded in the second wave of the study, and service use in the third wave.

RESULTS

Persons with a DSM-III-R disorder and persons with multiple functional impairments were three to seven times as likely to use primary or mental health care. People with low perceived social support were two to three times as likely to use them, and living alone increased the likelihood by 30% to 80%. The effect of mental disorder on service use was mediated by multiple functional impairments. In people with a mental disorder, low levels of social support intensified mental health service use.

CONCLUSION

Service utilization by people with mental problems can be better understood through a model incorporating: (1) independent effects of mental disorder, functional impairments and social support on service use; (2) a mediating effect of multiple functional impairments on the link between mental disorder and service use; and (3) interaction effects of mental disorder and low social support on service use.

The Profitability of Automatic Milking on Dutch Dairy Farms

Several studies have reported on the profitability of automatic milking based on different simulation models, but a data-based study using actual farm data has been lacking. The objective of this study was to analyze the profitability of dairy farms having an automatic milking system (AMS) compared with farms using a conventional milking system (CMS) based on real accounting data. In total, 62 farms (31 using an AMS and 31 using a CMS) were analyzed for the year 2003 in a case control study. Differences between the years 2002 and 2003 also were analyzed by comparing a subgroup of 16 farms with an AMS and 16 farms with a CMS. Matching was based on the time of investment in a milking system (same year), the total milk production per year, and intensity of land use (kg/ha). Results from 2003 showed that the farms with an AMS used, on average, 29% less labor than farms with a CMS. In contrast, farms using a CMS grew faster (37,132 kg of milk quota and 5 dairy cows) than farms with an AMS (-3,756 kg milk quota and 0.5 dairy cows) between 2002 and 2003. Dairy farmers with a CMS had larger (euro7,899) revenues than those with an AMS. However, no difference in the margin on dairy production was detected, partly because of numerically greater (euro6,822) variable costs on CMS farms. Dairy farms were compared financially based on the amount of money that was available for rent, depreciation, interest, labor, and profit (RDILP). The CMS farms had more money (euro15,566) available for RDILP than the AMS farms. This difference was caused by larger fixed costs (excluding labor) for the AMS farms, larger contractor costs (euro6,422), and larger costs for gas, water, and electricity (euro1,549). Differences in costs for contractors and for gas, water, and electricity were statistically significant. When expressed per full-time employee, AMS farms had greater revenues, margins, and gross margins per full-time employee than did CMS farms. This resulted in a substantially greater (but not statistically significant) RDILP per full-time employee (euro12,953) for AMS farms compared with CMS farms. Depreciation and interest costs for automatic milking were not available but were calculated based on several assumptions. Assuming larger purchase costs and a shorter depreciation time for AMS than for CMS, costs for depreciation and interest were larger for AMS farms than for CMS farms. Larger fixed costs should be compensated for by the amount of labor that has become available after introducing the milking robot. Therefore, farm managers should decide whether the extra time acquired by automatic milking balances against the extra costs associated with an AMS.