Availability of long-term psychological interventions for personality disorders is limited because of their high intensity and cost. Research in evidence-based, low-intensity interventions is needed.

This study aimed to examine the feasibility, acceptability and potential impact of a low-intensity, digital guided self-help (GSH) intervention that is focused on emotion regulation, recovery-oriented and provides in-the-moment delivery for patients with personality disorders.

We conducted a single-blind feasibility trial. A total of 43 patients with a personality disorder were recruited and randomly assigned to either a GSH arm (n = 22) or a treatment-as-usual arm (n = 21). The GSH intervention included a series of short videos offering psychoeducation and support, personalised feedback using text messages, and supportive telephone calls, for 4 weeks in addition to treatment as usual. Outcomes of emotional disturbance, emotion dysregulation, self-harm behaviours and decentring ability were measured at baseline, 4 weeks (end of intervention) and 8 weeks (follow-up).

All patients who attended the first session continued until the last session. There was an interaction effect between time and group on anxiety (P = 0.027, Δη2 = 0.10), where the GSH group showed a significant reduction in anxiety at follow-up (P = 0.003, d = 0.25). The GSH group increased in decentring ability at the end of intervention (P = 0.007, d = −0.65), and the decrease in self-harm behaviours continued until follow-up (P = 0.02, d = 0.57).

The results suggest that a personalised digital GSH with a focus on recovery could reduce anxiety and self-harm behaviours at short-term follow-up.