For example, sudden onset of severe anxiety around trivial stressors in a previously highly-functioning, well-adjusted individual in their mid-40’s who had never experienced such challenges should prompt consideration of a non-primary psychiatric etiology.6 Ghahremani et al. found correlations between levels of a well-validated AD biomarker, plasma phosphorylated tau at threonine 181 (p-tau181) and MBI, although not individual NPS.241 Over a 1-year period, MBI was associated with higher p-tau181 levels as well as decline in memory and executive function. This evidence concerns the gene MAPT and Alzheimer disease.