Pharma Consulting Group AB (www.pharmaconsultinggroup.com) has conducted block randomization for each sub-study group, stratified for gender and age (sub-study 1: < or >=30 years; sub-study 2: < or >=35 years). Power calculation was also carried out by Pharma Consulting Group based on findings from a previous RCT in our group assessing the effect of 8 weeks of EPO treatment on the same cognitive composite score. In this trial, the clinically relevant differential change between EPO and saline groups following 12 weeks of treatment is assumed to be at least 0.4 SD (corresponding to a moderate effect size) on the primary outcome with SD of the change of 0.5. Assuming a 10% drop-out rate, we plan to recruit up to n=58 for each sub-study to achieve complete data sets for n=52 participants per sub-study.