High rates of co-occurring depression are reported in autism spectrum disorder (ASD), a neurodevelopmental condition characterised by social communication impairments and repetitive behaviours. Cognitive-behavioural interventions adapted for ASD have been effective for anxiety problems. There have been evaluation studies of group cognitive-behavioural therapy for co-occurring depression, but no randomised trials investigating low-intensity psychological interventions as recommended in clinical guidelines for mild-moderate depression. Open Access Article