AbstractObjectiveStressful life events have been implicated in the onset of psychotic disorders, but there are few robust studies. We sought to examine the nature and magnitude of associations between adult life events and difficulties and first-episode psychoses, particularly focusing on contextual characteristics, including threat, intrusiveness, and independence.MethodThis study forms part of the Childhood Adversity and Psychosis Study (CAPsy), an epidemiological case-control study in London, United Kingdom. Data on life events and difficulties (problems lasting 4 wk or more) during 1 year prior to onset (cases) or interview (controls) were assessed using the semi-structured Life Events and Difficulties Schedule (LEDS). Data were available on 253 individuals with a first episode of psychosis and 301 population-based controls.ResultsWe found strong evidence that odds of exposure to threatening and intrusive events in the 1 year prior to onset were substantially higher among cases compared with controls, independent of age, gender, ethnicity, and social class (ORs > 3). This was consistent across diagnostic categories. We found further evidence that the effect of threatening events and difficulties was cumulative (1 event odds ratio [OR] 2.69 [95% confidence interval (CI) 1.51–4.79]; 2 events OR 4.87 [95% CI 2.34–10.16]; ≥3 events OR 5.27 [95% CI 1.83–15.19]; 1 difficulty OR 3.02 [95% CI 1.79–5.09]; 2 difficulties OR 9.71 [95% CI 4.20–22.40]; ≥3 difficulties OR 12.84 [95% CI 3.18–51.85]).ConclusionsThreatening and intrusive life events and difficulties are common in the year pre-onset among individuals with a first episode of psychosis. Such experiences may contribute to the development of psychotic disorders.