Neuropsychiatric Symptoms in AD: Clinical Trials Targeting Mild Behavioral Impairment: A Report from the International CTAD Task Force

The International CTAD Task Force (TF) addressed challenges related to designing clinical trials for agitation in dementia, presenting accomplishments from the two previous TFs on neuropsychiatric symptoms (NPS). In addition, this TF proposed a paradigm shift in NPS assessment and management, presenting Mild Behavioral Impairment (MBI) as a clinical syndrome. MBI is marked by later-life emergent and persistent NPS in dementia-free older persons (ranging from cognitively unimpaired to subjective cognitive decline to mild cognitive impairment), which facilitates earlier detection and better prognostication of Alzheimer's disease (AD). The TF has made the following recommendations for incorporation of NPS into AD preventative trials: (1) clinical trials targeting improvement in MBI symptoms should be undertaken; (2) treatment trials for MBI should be disease specific and confirm the diagnosis of participants using biomarkers; trials should include measures sensitive to cognitive changes in preclinical AD, which can serve as outcome measures, in addition to changes in biomarker levels; (3) as a first step, pharmacotherapeutic trials should address the full MBI complex as well as the specific symptoms/domains that constitute MBI; (4) clinical trials using problem-adaptation psychotherapy to target affective MBI should be considered; and (5) MBI should be considered in AD trials of disease modifying therapies. The well-validated and widely-used MBI Checklist (MBI-C) is an appropriate symptom rating scale for these studies, as it was developed specifically to identify and measure MBI in dementia-free persons. Other scales such as the Neuropsychiatric Inventory (NPI) may be used, although administration at two timepoints may be necessary to operationalize the MBI criterion of symptom persistence.