Sas university edition software version 9.4

Statistical analyses were performed with SAS University Edition software version 9.4 (SAS Institute, Cary, NC, USA). Data were tested for normality of distribution using the Shapiro-Wilk test. For the pre-post comparisons of the entire sample, paired t-tests were conducted for normally distributed data (with pooled or Satterthwaite approximations when equal and non-equal variances were encountered, respectively), and signed rank test was conducted for non-normally distributed data.
We also performed comparisons between individuals with and without the BDNF Val66Met polymorphism. We assessed normality using the Shapiro-Wilk test. Then, we assessed baseline equivalence using independent-sample t-tests (with pooled or Satterthwaite approximations when equal and non-equal variances were encountered, respectively). None of the outcome measures in this analysis significantly deviated from a normal distribution. We conducted pre-post comparisons between the two subgroups using independent-sample t-tests. All analyses were two-tailed, the level of significance was set to p < 0.05 and we report outcomes using the mean and standard deviation (SD). Pre-post changes that achieved a p-value of at least 0.1 are reported as statistical trends, and in these instances, the median and interquartile ranges are also reported.