Psychological functioning 1 year after a brief intervention using micronutrients to treat stress and anxiety related to the 2011 Christchurch earthquakes: a naturalistic follow-up

Objective We investigated whether micronutrients given acutely following the Christchurch earthquakes continued to confer benefit 1 year following the treatment. Methods Sixty‐four adults from the original 91 participants experiencing heightened anxiety or stress 2–3 months following the 22nd February 2011 earthquake and who had been randomized to receive three different doses of micronutrients completed on‐line questionnaires assessing mood, anxiety, stress, and symptoms associated with post‐traumatic stress disorder 1 year after completing the initial study. Twenty‐one out of 29 nonrandomized controls who did not receive the treatment also completed the questionnaires. Results Both the treated and control groups experienced significant improvement in psychological functioning compared with end‐of‐trial. However, treated participants had better long‐term outcomes on most measures compared with controls (ES = 0.69–1.31). Those who stayed on micronutrients through to follow‐up or stopped all treatment reported better psychological functioning than those who switched to other treatments including medications. About 10% of the sample continued to have post‐traumatic stress disorder symptoms. Conclusions Disaster survivors improve psychologically over time regardless of receiving intervention; however, those taking micronutrients during the acute phase following a disaster show better outcomes, identifying micronutrients as a viable treatment for acute stress following a natural disaster with maintenance of benefits 1 year later. ACTRN 12611000460909 Copyright © 2014 John Wiley & Sons, Ltd.