Changes in the prevalence of bipolar disorders between 1998 and 2008 in an Australian population.
ABSTRACT To identify any changes in the prevalence of bipolar disorder (BD) between 1998, 2004, and 2008.
Cross-sectional population-based surveys were conducted involving random and representative samples of South Australian adults aged ≥ 15 years. BD was assessed using the mood module of the Primary Care Evaluation of Mental Disorders instrument (PRIME-MD), a single question related to doctor-diagnosed BD and the Mood Disorder Questionnaire (MDQ), which defines bipolar spectrum disorder.
The PRIME-MD-derived prevalence of BD increased significantly from 0.5% [95% confidence interval (CI): 0.27-0.79] in 1998 to 1.0% (95% CI: 0.61-1.31) in 2004 and 1.5% (95% CI: 1.05-1.91) in 2008, demonstrating a significant increased linear trend (χ² =13.91, df=2, p=0.002). Similarly, reported doctor-diagnosed BD increased significantly from 1.1% (95% CI: 0.75-1.51) in 1998 to 1.7% (95% CI: 1.26-2.18) in 2004 and 2.9% (95% CI: 2.28-3.48) in 2008 (Linear trend test χ²=24.55, df=2, p<0.001). The MDQ-derived diagnosis of bipolar spectrum disorder changed from 2.5% (95% CI: 1.96-3.08) in 2004 to 3.3% (95% CI: 2.66-3.94) in 2008 (χ² =3.22, df=1, p<0.10), but this difference did not attain statistical significance. Confining the analysis to those positive for BD on all three methods, there was a significant increase in the prevalence of the detection of BD using all three measures (χ² =4.43, df=1, p=0.03) between 2004 and 2008.
There has been an increased prevalence of BD in South Australia over the last decade, but this may be related to changing diagnostic practices rather than a true increase.
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ABSTRACT: Eight hundred twenty-three relatives of bipolar and schizoaffective patients were divided into groups of birth cohorts. The rates of bipolar, schizoaffective, and unipolar disorders were higher in the cohorts born after 1940 than in the cohorts born earlier. Life-table analysis of the cumulative hazard of illness in the different cohorts revealed significant differences among them, implying that the cumulative hazard of developing any affective disorder by a given age was greater in the post-1940 cohorts. When these data are combined with other reports, an ominous trend may be present, leading to an increase in prevalence of a broad spectrum of familial affective disorders in the coming decades.Archives of General Psychiatry 05/1987; 44(4):314-9. · 13.77 Impact Factor
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ABSTRACT: Lifetime rates are presented for 15 DSM-III psychiatric diagnoses evaluated in three large household samples on the basis of lay interviewers' use of the Diagnostic Interview Schedule. The most common diagnoses were alcohol abuse and dependence, phobia, major depressive episode, and drug abuse and dependence. Disorders that most clearly predominated in men were antisocial personality and alcohol abuse and dependence. Disorders that most clearly predominated in women were depressive episodes and phobias. The age group with highest rates for most disorders was found to be young adults (aged 25 to 44 years). Correlates with race, education, and urbanization are presented.Archives of General Psychiatry 11/1984; 41(10):949-58. · 13.77 Impact Factor