Psychiatric Case Study Summary

Study Summary

Numerous studies have emerged over the past several decades purporting the association between prenatal and/or childhood exposure to infectious agents and the onset of mental illnesses such as schizophrenia (Brown & Derkits, 2010). Mortensen et al completed a study in 2007 examining the serological markers of 413 people born in Denmark in 1981 or later and were registered with the Danish Psychiatric Case Register as having received a diagnosis for schizophrenia or related disorder. Beginning the 1970s, Denmark and many other countries tested babies for metabolic conditions such as phenylketonuria (PKU) with a heel stick upon birth, and often times these blood samples were stored for later observation (Mortensen et al, 2007). The

Researchers involved in this study examined maternal serum samples of women who gave birth in northern California between 1959 and 1966 for influenza antibodies specific to strains that were prevalent during the time they were pregnant (Brown et al 2004). All participants in this study were previously enrolled in the Child Health and Development Study and therefore, offspring of the women were easily identified through their database (Brown et al 2004). Once the offspring were identified, computer records were analyzed to identify potential cases as having received a prior schizophrenia spectrum disorder (SSD) diagnosis (Brown et al 2004). These potential cases were then screened by trained clinicians to verify the presence of such diagnosis (Brown et al 2004). There were a total of 64 cases yielded and were then matched with a total of 125 controls (Brown et al 2004). The researchers then examined the association between prenatal influenza exposure and the risk for developing a schizophrenia spectrum disorder (Brown et al

In older studies, researchers mainly used maternal recall to define influenza exposure, which ultimately lead to an undetermined amount of recall bias and inaccurate findings (Brown et al 2004).Comparable to Study 1, this was also a population based case-control study. One of the main strengths for employing a case-control method for this study is that schizophrenia is a relatively uncommon disease with a prevalence of about 1.1% of adults in the U.S. (NIMH, 2009). It would be difficult to assess a large enough group to ensure enough cases to accurately evaluate findings in a cohort study. Additionally, since schizophrenia can take decades to emerge, there is a probability a large portion of participants would be lost to follow-up if this study was conducted in a cohort- style method. All in all, based on the low prevalence and the long latent period of schizophrenia, a case-control study seems the most appropriate method for this