Additionally, several possible confounding factors, such as the presence or absence of AD and MCI, the presence of APOE‐ε4 carriers, a positive family history of AD, the presence of comorbidities like cardiovascular diseases, depression profiles of participants, patients' age and sex, BMI, and medications like hormonal therapy, might have influenced FDG‐PET findings. The gene discussed is APOE; the disease is depressive disorder.