The epidemiology of bipolar affective disorder; a review of the literature and introduction to work in progress

Population-based affective-disorder-related biomedical/biophysical multi-hyper-morbidity across the lifespan: A 16-year population study

BACKGROUND

There are few if any life-span population-based studies of psychiatric disorder-associated biomedical and biophysical disorders and diseases (morbidity).

AIM

To scope the present state of research regarding the biomedical and biophysical morbidity associated with affective and mental disorder in epidemiological samples, and to examine the life-span relationship between affective disorders and biomedical/biophysical disorders to illustrate a novel approach employing the odds ratio to represent the intensity of biomedical and biophysical morbidity associated in time in a population.

METHODS

A repeatable systematic literature search of PubMed was represented in summary. Additionally, a regional population-based dataset was constructed and analyzed to represent the age- and sex-specific diagnoses (International Classification of Diseases Version 9, ICD-9) for those with and without affective disorder. The analysis presents a novel index of the relative age-specific frequency of life-span biomedical and biophysical diagnoses associated with affective disorder.

RESULTS

The volume of biomedical and biophysical morbidity associated with mental disorder literature has increased, yet few studies measure comprehensive temporal hyper-morbidity (over-representation of diseases over time, either before or after the index diagnostic event) in populations. Further, there have been only a few population-based studies examining the morbidity associated with affective disorder and only one that examines the full diagnostic range of lifespan morbidity. Substantial differences arose between males and females with more females than males having greater frequencies of diagnoses. The age-specific distributions of the maximum proportional diagnosis frequency ratios for each sex illustrate the greatest diagnosis-specific differences when comparing the biomedical and biophysical diagnoses of those with and without affective disorder when the same diagnosis was represented in each grouping at the same age.

CONCLUSION

Clinical research needs to focus on more than one or two comorbid biomedical or biophysical disorders at a time. Comprehensive population-based examination of the lifespan biomedical and biophysical multi-morbidity associated with affective disorder has the potential to directly inform clinical practice. Representing the proportional ratios of age-specific frequency of diagnoses for the full range of ICD-9 diagnoses is a novel analytical model. Diagnostic frequency appears a viable representation of a given disease state, such as affective disorder. Fortunately, the WPA has developed a global education section to better understand the biomedical and biophysical morbidity associated with all psychiatric disorders. This has been identified by the WPA as the psychiatric practice challenge of the 21^st century.

Risk factors in relation to an emergence of bipolar disorder: a systematic review

OBJECTIVE

There is a consensus that genetic factors are important in the causation of bipolar disorder (BPD); however, little is known about other risk factors in the aetiology of BPD. Our aim was to review the literature on such risk factors - risk factors other than family history of affective disorders - as predictors for the initial onset of BPD.

METHODS

We conducted a literature search using the MEDLINE, PsycINFO and EMBASE databases. We selected factors of interest including demographic factors, factors related to birth, personal, social and family backgrounds, and history of medical conditions. The relevant studies were extracted systematically according to a search protocol.

RESULTS

We identified approximately 100 studies that addressed the associations between antecedent environmental factors and a later risk for BPD. Suggestive findings have been provided regarding pregnancy and obstetric complications, winter-spring birth, stressful life events, traumatic brain injuries and multiple sclerosis. However, evidence is still inconclusive. Childbirth is likely to be a risk factor. The inconsistency across studies and methodological issues inherent in the study designs are also discussed.

CONCLUSION

Owing to a paucity of studies and methodological issues, risk factors of BPD other than family history of affective disorders have generally been neither confirmed nor excluded. We call for further research.