and higher amyloid plaque density (in the superior temporal gyrus, orbitofrontal gyrus, and the inferior parietal cortex) were associated with increased severity of dementia. Along with these biological factors, when the patient also had the apolipoprotein E (ApoE4) allele (a known genetic risk factor for Alzheimer's disease), the amyloid plaques increased although the hippocampal neurofibrillary tangles did not. It showed an increased genetic susceptibility to more severe dementia with Alzheimer's disease than without the genetic marker. As seen in the examples above, although memory does degenerate with age, it is not always classified as a memory disorder. The difference in memory between normal aging and a memory disorder is the amount of beta-amyloid deposits, hippocampal neurofibrillary tangles, or amyloid plaques in the cortex. If there is an increased amount, memory connections become blocked, memory functions decrease much more than what is normal for that age and a memory disorder is diagnosed. The cholinergic hypothesis of geriatric memory dysfunction is an older hypothesis that was considered before beta-amyloid deposits, neurofibrillary tangles, or amyloid plaques. It states that by blocking the cholinergic mechanisms in control subjects you can examine the relationship between cholinergic dysfunction and normal aging and memory disorders because this system when dysfunctional creates memory deficits. Cultural perspectives The pervasiveness of mental health illnesses can be illustrated by looking at the size of the Diagnostic and Statistical Manual IV-TR (DSM IV-TR). Epidemiological studies have shown an increase in mental health cases globally. In 2050, there could be a pandemic of neurological diseases. An aging baby-boom population increases the demand for mental health care. Western culture's gauge of mental illness is determinate on level of dangerousness, competence, and responsibility. This has led to many individuals being denied jobs, less likely to be able to rent apartments, and more likely to have false criminal charges pressed against them. The level of services available to an ever aging and memory-impaired demographic will need to increase in spite of the stigma against mental illness. With such a stigmatization of memory disorders, and mental illnesses in general, it can be especially hard for those providing aid for these individuals. Some individuals “are unable to acquire or retain new information, making it difficult or impossible to meet social, family and work-related obligations.” Because of this, there is a large responsibility placed on caregivers (usually children) to uphold economic and emotional upkeeps. While there are services available