Cognitive Reflection Test (CRT) Practice 2026 - Free Cognitive Reflection Test Practice Questions and Study Guide

Apolipoprotein E4 (APOE 4) testing is significant in identifying Alzheimer’s disease because the presence of the APOE ε4 allele is associated with an increased risk of developing the disease. Individuals who carry one or two copies of this allele have a higher likelihood of experiencing cognitive decline and developing Alzheimer’s compared to those who do not have the gene variant. While this test is not definitive for diagnosing Alzheimer’s, it can indicate a predisposition to the disease, especially when combined with other clinical assessments and imaging studies.

In contrast, the other tests listed do not specifically target Alzheimer's disease. A complete blood count is primarily used to assess overall health and detect various disorders, but it does not provide information relevant to diagnosing Alzheimer’s. Liver function tests evaluate liver health and do not pertain to cognitive disorders. Thyroid function tests assess how well the thyroid is working and might help rule out other causes of cognitive impairment but are not specific indicators for Alzheimer's disease itself.