Procedure
self-harm
At baseline, after participants gave informed consent, all were presented with the original intervention aimed at reducing self-harm. Participants were then randomised via online survey software to receive, at six-month follow-up, either: (a) the same version of the intervention, or (b) a version of the intervention that had been changed following participant feedback. Whilst participants were not expected to use the intervention in the period between baseline and follow-up, the volitional help sheet is intended to provide people with a means of responding to critical situations (where the urge to self-harm may be heightened), with automatic coping plans that were formed during the baseline period.