National guidance cautions against low-intensity interventions for people with personality disorder, but evidence from trials is lacking.

To test the feasibility of conducting a randomised trial of a low-intensity intervention for people with personality disorder.

Single-blind, feasibility trial (trial registration: ISRCTN14994755). We recruited people aged 18 or over with a clinical diagnosis of personality disorder from mental health services, excluding those with a coexisting organic or psychotic mental disorder. We randomly allocated participants via a remote system on a 1:1 ratio to six to ten sessions of Structured Psychological Support (SPS) or to treatment as usual. We assessed social functioning, mental health, health-related quality of life, satisfaction with care and resource use and costs at baseline and 24 weeks after randomisation.

A total of 63 participants were randomly assigned to either SPS (n = 33) or treatment as usual (n = 30). Twenty-nine (88%) of those in the active arm of the trial received one or more session (median 7). Among 46 (73%) who were followed up at 24 weeks, social dysfunction was lower (−6.3, 95% CI −12.0 to −0.6, P = 0.03) and satisfaction with care was higher (6.5, 95% CI 2.5 to 10.4; P = 0.002) in those allocated to SPS. Statistically significant differences were not found in other outcomes. The cost of the intervention was low and total costs over 24 weeks were similar in both groups.

SPS may provide an effective low-intensity intervention for people with personality disorder and should be tested in fully powered clinical trials.