Individuals who have schizophrenia are known to be at a higher risk of developing diabetes, cardiovascular disease, obesity and hyperlipidemias, all of which are concomitant with an increased risk for dementia. Therefore, the question of whether or not schizophrenia and dementia are related has long been hypothesized. Throughout the years, numerous studies have been conducted hoping to finally provide an answer. Alas, they have all been inconclusive; that is, until now.
In a recent study, Dr. Anette Ribe and a host of others collected data from over 2.8 million Danes obtained thru national health registries in Denmark. The study spanned the years 1995-2013 (18 years). The data collected was for individuals who were age 50 or who turned 50 during the eighteen years being reviewed. More than 136,000 of those people acquired a progressive form of dementia during that time. Additionally, more than 20,600 of the individuals being followed were already diagnosed with schizophrenia or developed it during the 18 years being studied.
When the group began to compile the data, they found that before age 65 the risk of developing dementia was .6% for people without schizophrenia but 1.8% for those with it. Out of the 2.8 million studied, 944 individuals were diagnosed with schizophrenia. Of those 944 individuals, 211 of them were diagnosed with dementia before age 65. That’s a whopping 22.4%! However, once reaching age 80, the correlation is less impressive. It is still pertinent, though, with 5.8% chance for those without schizophrenia developing dementia and 7.4% for those with it.
Comparing the above data with currently known statistics better helped support the hypothesis that dementia and schizophrenia are related. The study found that 22.4% of those with schizophrenia would also be diagnosed with dementia before age 65 versus the current national average for those without schizophrenia developing dementia, which is 6.3%. That’s an increase of 16.1%. Currently, scientists have not been able to identify the reason for this increase but have begun research in hopes of finding an answer.
Ribe, A. R., Laursen, T. M., Charles, M., Katon, W., Fenger-Gron, M., Davydow, D., Vestergaard, M. (2015). JAMA Psychiatry. JAMA Psychiatry, 72(11), 1095-1101. Retrieved March 7, 2016, from http://archpsyc.jamanetwork.com
Rubin, E. (2016, March 7). The Relationship between Schizophrenia and Dementia. Retrieved March 07, 2016, from https://www.psychologytoday.com/blog/demystifying-psychiatry/201603/the-relationship-between-schizophrenia-and-dementia
WKPIC Doctoral Intern