There is a growing recognition that having a difficult or traumatic childhood can increase the likelihood of people developing psychosis later in life but it is difficult to disentangle what types of trauma or abuse are linked to an increased risk. A team of researchers from the Institute of Psychiatry, King's College London looked into this further in a study of 428 people, 182 of whom had psychosis. The researchers asked people about difficulties and problems in their childhood and found that people with psychosis were three times more likely to report severe physical abuse by their mother before they were 12. There was also some - although not statistically significant - evidence that 'severe maternal antipathy' was linked to an increased risk of psychosis. However, paternal maltreatment and other forms of adversity were not linked to an increased risk of psychosis.
Fisher, H.L. ... [et al] - The varying impact of type, timing and frequency of exposure to childhood adversity on its association with adult psychotic disorder Psychological Medicine (2010), 40, 1967–1978