Morgan Vera A, Leonard Helen, Bourke Jenny, Jablensky Assen
Neuropsychiatric Epidemiology Research Unit, School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Australia.
Br J Psychiatry. 2008 Nov;193(5):364-72. doi: 10.1192/bjp.bp.107.044461.
The epidemiology of intellectual disability co-occurring with schizophrenia and other psychiatric illness is poorly understood. The separation of mental health from intellectual disability services has led to a serious underestimation of the prevalence of dual diagnosis, with clinicians ill-equipped to treat affected individuals.
To estimate the prevalence of dual diagnosis and describe its clinical profile.
The Western Australian population-based psychiatric and intellectual disability registers were cross-linked (total n=245,749).
Overall, 31.7% of people with an intellectual disability had a psychiatric disorder; 1.8% of people with a psychiatric illness had an intellectual disability. Schizophrenia, but not bipolar disorder and unipolar depression, was greatly over-represented among individuals with a dual diagnosis: depending on birth cohort, 3.7-5.2% of those with intellectual disability had co-occurring schizophrenia. Pervasive developmental disorder was identified through the Intellectual Disability Register and is therefore limited to individuals with intellectual impairment. None the less, pervasive developmental disorder was more common among people with a dual diagnosis than among individuals with intellectual disability alone. Down syndrome was much less prevalent among individuals with a dual diagnosis despite being the most predominant cause of intellectual disability. Individuals with a dual diagnosis had higher mortality rates and were more disabled than those with psychiatric illness alone.
The facility to combine records across administrative jurisdictions has enhanced our understanding of the epidemiology of dual diagnosis, its clinical manifestations and aetiological implications. In particular, our results are suggestive of a common pathogenesis in intellectual disability co-occurring with schizophrenia.
人们对与精神分裂症及其他精神疾病共病的智力残疾的流行病学情况了解甚少。精神健康服务与智力残疾服务的分离导致对双重诊断患病率的严重低估，临床医生也缺乏治疗受影响个体的能力。
估计双重诊断的患病率并描述其临床特征。
将西澳大利亚基于人群的精神疾病和智力残疾登记册进行交叉关联（总数n = 245,749）。
总体而言，31.7%的智力残疾患者患有精神疾病；1.8%的精神疾病患者存在智力残疾。在双重诊断个体中，精神分裂症（而非双相情感障碍和单相抑郁症）的比例过高：根据出生队列不同，3.7 - 5.2%的智力残疾患者同时患有精神分裂症。广泛性发育障碍是通过智力残疾登记册确定的，因此仅限于有智力障碍的个体。尽管如此，广泛性发育障碍在双重诊断患者中比仅患有智力残疾的个体更为常见。唐氏综合征在双重诊断个体中的患病率要低得多，尽管它是智力残疾最主要的病因。与仅患有精神疾病的个体相比，双重诊断个体的死亡率更高且残疾程度更严重。
跨行政辖区合并记录的便利条件增进了我们对双重诊断的流行病学、临床表现及病因学意义的理解。特别是，我们的结果提示智力残疾与精神分裂症共病存在共同的发病机制。
