Neuritic pathology is lacking in the entorhinal cortex,subiculum and hippocampus in middle-aged adults with schizophrenia,bipolar disorder or unipolar depression

Earlier reports have provided conflicting results regarding the association between Alzheimer's disease (AD) and mental disorders. Using a well-characterized postmortem series of 40 middle-aged human brains, we have performed quantitative analysis of neurofibrillary tangles and senile plaques in the entorhinal cortex, subiculum and rostral hippocampus in 9 subjects with schizophrenia, 8 with bipolar disorder, 12 with depression, and 11 age- and sex-matched controls. No significant differences were found among the four groups. Our study indicates that the Alzheimer-type changes, which might be related to the likelihood of AD development later in life, are not increased in middle-aged subjects with mental illness. The result also supports the more recent reports that have demonstrated no increased incidence of AD in mentally ill patients.