Objectives The interpersonal‐psychological theory (IPT) of suicidal behavior suggests that an individual who does not feel they belong and believes they are a burden combined with the capability to attempt suicide is more likely to attempt suicide. The study aimed to investigate this hypothesis in the context of psychosis. Method Young people with a first episode of psychosis (N = 45) who considered suicide, attempted suicide, and had no history of suicide or attempt were compared on self‐report measures of suicidal desire, capability for suicide, and substance use. Results No significant differences were found between groups in terms of suicidal desire or capability. All participants perceived they were a burden, did not feel they belonged, and had the capability for suicide. Poisoning (n = 22) was the most frequently reported method of a suicide attempt. Of those who had attempted suicide, 50% (n = 7) reported that it had been related to a psychotic episode. Of the participants, 30 reported previous suicidal ideation mainly to completely end or stop the distress they were experiencing. Levels of depression were significantly different between groups; moderate levels of depression were reported in the suicidal ideation and attempt groups. Conclusion The concepts of IPT appear to resonate with the experience of psychosis, regardless of suicidality. Specific features of psychosis and their influence on suicidality are worth further exploration.