The present study was undertaken to explicate findings of elevated blood potassiums (K+) among inpatient addiction treatment patients. A higher mean blood K+ level was established to exist for these patients compared to reference groups. This was investigated by comparing "high" and "normal" K+ groups within our patient group on several demographic variables and on the usage of various drugs. Multiple regression analyses were computed in an attempt to predict K+ levels. Age alone was found to be the best predictor after elimination of nonsignificant variables. Adolescents and young adults may differentially favor substances that raise K+ levels. Elevated blood K+ levels among adolescents and young adults may alert practitioners to specifically explore substance use disorders.