Abstract
Accumulating evidence shows that loneliness in psychosis is a major concern for patients, is associated with poorer mental and physical health, and is a significant barrier to recovery. Although psychologists play a major role in treating the cognitive, emotional, and social difficulties of people with psychosis, loneliness is rarely addressed. This article presents a structured review and critique of the evidence base on loneliness in youth and adults with psychosis, framed around the knowledge, attitudes, and skills comprising clinical competencies as a foundation for clinical practice.