We explored the prevalence of autism and attention-deficit hyperactivity disorder in first-episode psychosis. Through service evaluation involving 509 individuals, detailed analyses were conducted on neurodevelopmental traits and patterns of service utilisation. Prevalence of neurodivergence in first-episode psychosis was 37.7%. Neurodivergent individuals used urgent mental health services more frequently (Mann-Whitney U = 25925, Z = -2.832, P = 0.005) and had longer hospital stays (Mann-Whitney U = 22816, Z = -4.886, P ≤ 0.001) than non-neurodivergent people. Neurodivergent people spend more than twice as long in mental health hospitals at a time than the non-neurodivergent people (Mann-Whitney U = 22 909.5, Z = -4.826, P ≤ 0.001). Mediation analysis underscored indirect impact of neurodivergence on hospital stay durations through age at onset of psychosis and use of emergency services. Prevalence of neurodevelopmental conditions in first-episode psychosis is underestimated. Neurodivergent individuals show increased utilisation of mental health services and experience psychosis earlier. Early assessment is crucial for optimising psychosis management and improving mental health outcomes.