Aims and methodTrue Colours is an automated symptom monitoring programme used by National Health Service psychiatric services. This study explored whether patients with unipolar treatment-resistant depression (TRD) found this a useful addition to their treatment regimes. Semi-structured qualitative interviews were conducted with 21 patients with TRD, who had engaged in True Colours monitoring as part of the Lithium versus Quetiapine in Depression study. A thematic analysis was used to assess participant experiences of the system.ResultsSix main themes emerged from the data, the most notable indicating that mood monitoring increased patients' insight into their disorder, but that subsequent behaviour change was absent.Clinical implicationsPatients with TRD can benefit from mood monitoring via True Colours, making it a worthwhile addition to treatment. Further development of such systems and additional support may be required for patients with TRD to experience further benefits as reported by other patient groups.