This dataset measures razor clam consumption, memory, clerical speed and accuracy, and depression to study the long term impact of lower level doses of the marine-based neurotoxin, domoic acid. Data was collected over an eight year period, between the years 2009 and 2020. Data was collected from 500 randomly selected Native Americans between the ages of 18 and 64 who resided in the coastal communities of the Pacific Northwest United States. Demographic and medical history were obtained using standardized interview procedures. Substance use, and razor clam consumption history were obtained using the brief Michigan Alcoholism Screen Test (BMAST), Drug Abuse Screen Test (DAST), and a Shellfish Assessment Survey.