Mixed Methods Thematic Analysis of a Randomised Controlled Trial of Adjunctive Mitochondrial Agents for Bipolar Depression

OBJECTIVE: There is often a shortfall in recovery following treatment for an episode of bipolar disorder (BD). Exploration of participant’s experience provides vital information to enhance statistical outcomes for novel therapy trials. This study used mixed-methods to explore participants’ experience of a trial testing N-acetyl cysteine (NAC) and mitochondrially active nutraceuticals for BD depression. METHODS: Case report forms from a randomised controlled trial (RCT) of BD depression (n = 148) were analysed using a pragmatic adaption of grounded theory and thematic analysis. RESULTS: Thematic analysis of 148 study participants indicated numerous changes in participant experience over time. For example, perceived environmental stressors reported by participants decreased over the trial in both treatment groups. Quantitative analysis of the themes revealed more positive theme reports in the combination treatment arm compared to the placebo arm and there were more negative themes identified in the placebo arm, compared to the NAC arm. CONCLUSION: This approach revealed additional results not elucidated in the primary quantitative analysis. This emphasises the value of mixed-methods research in capturing participants’ experiences in RCTs and detecting possible latent benefits and risks. Such methods can detect latent target signals in novel therapy trials conducted in BD and generate novel hypotheses.