Participant demographics.

Mental health-related discrimination by friends, family members and intimate partners is especially common, particularly in the form of avoidance and dismissive reactions. In contrast, good quality initial support (mental health first aid) is thought to improve help-seeking and mental health outcomes, although there are few studies that have examined this. This study aimed to develop a measure of mental health support skills that could be self-reported by the recipient of help, and to use this measure to test whether better quality support was related to better outcomes. We recruited 1116 adults from Prolific who reported a recent mental health problem or crisis and were helped by someone close to them such as a family member or friend. Participants completed a recipient version of the Mental Health Support Scale, which asked about actions the other person took to support them, based on mental health first aid guidelines. They also completed measures assessing convergent and divergent validity and perceived impact of the support from their helper. Confirmatory factor analysis supported a scale with two factors of recommended and not recommended actions with acceptable psychometric properties. Receiving recommended mental health first aid support was associated with perceived benefits by the recipient of help, including improved mental health (r = .37), a closer relationship with their helper (r = .39), and impact on help seeking from a doctor (r = .45), mental health professional (r = .49) or a phone or digital mental health service (r = .38). These findings provide empirical evidence for the potential benefits of upskilling community members in effective mental health first aid support.