A conspiracy world view may be a form of mistrust that is typically corrosive to individual and societal well-being. Our aim was to establish the correlates of conspiracy thinking in an epidemiologically representative sample.US National Comorbidity Survey-Replication (NCS-R) data were analysed from 5645 people who had completed the item "I am convinced there is a conspiracy behind many things in the world." Results were weighted to be representative of the US adult English speaking household population.1618 people (weighted 26.7%) endorsed the conspiracy belief item. These individuals were more likely to be: male; currently unmarried; less educated; in a lower income household; outside the labour force; from an ethnic minority group; not attending religious services; taking a weapon outside; and perceiving themselves as of lower social standing compared to others. Individuals endorsing the conspiracy belief item had lower levels of physical and psychological well-being, higher levels of suicidal ideation, weaker social networks, less secure attachment style, difficult childhood family experiences, and were more likely to meet criteria for a psychiatric disorder. There were no differences between those who endorsed conspiracy beliefs and those who did not in age, importance of religious beliefs in daily life, body mass index, or in having a gun at home.Viewing conspiracies in the world is associated with a raised risk of a wide range of adverse circumstances. It is a type of cognitive style that requires systematic empirical study, including monitoring of prevalence, tests of causation, and modelling of propagation.