Eur Child Adolesc Psychiatry (2009) 18:645–651 PRS. A supplementary article [12], brought to our attention by a colleague, mentioned 20 more cases of PRS. Owing to a lack of detail, however, these cases could not be incor- porated into our study population (n = 24). Population characteristics of the 24 patients are presented in Table 1. The search on PsychInfo also yielded three textbooks on eating disorders [14, 16, 22] in which PRS is mentioned. Remarkably, the two main textbooks on child and ado- lescent psychiatry [15, 20] contain no information at all about PRS. The DSM-IV [1] and ICD-10 [29] do not classify PRS. Epidemiology Pervasive refusal syndrome is most often seen in girls between the ages of 7 and 15. As illustrated in Table 1, 75% of the 24 patients were female and the mean age of the population was 10.5 years. Kate perfectly ﬁts this proﬁle. Occurrence of PRS in adults has not been reported. The incidence of the disorder is unknown [11]. Aetiology In the ﬁrst article published on PRS [13], there seemed to be an association between PRS and sexual abuse. Later articles denied such an association. Reviewing the litera- ture, however, sexual abuse was reported in 21% of the 24 cases (see Table 2), which is not an insigniﬁcant percent- age. Trauma, in general, seems to be an important aetio- logical factor, since PRS is also often seen in refugees and witnesses to violence (see Table 2). Nunn and Thompson [18] introduced the concept of learned helplessness and hopelessness. They proposed that the symptoms seen in children with PRS emerge from the perceived uncontrollability of their future and the Table 1 Population characteristics PRS (n = 24)a, 1991–2006 Characteristics Age (mean ± SD) Male n Age (mean ± SD) Female n Age (mean ± SD) Ethnicity Not reported Asian White Frequency (total n = 24) 10.5 ± 2.6 6 (25%) 9.0 ± 3.3 18 (75%) 10.9 ± 2.2 15 (63%) 5 (21%) 4 (17%) a Twenty-three patients from the literature search ? 1 patient from the Dutch article [25] 647 Frequency (total n = 24) Table 2 Aetiologic factors of PRS (n = 24)a, 1991–2006 Aetiologic factors Premorbid personality High-achieving, perfectionist, conscientious Psychiatric history of child Positive Negative Not reported Psychiatric history of parents Positive Negative Not reported Enmeshed mother–child relationship/over-involvement Positive Not reported Known stressors Witness to violence Refugee Sexual abuse Marital/parental problems Relocation Family loss Change of school Emotional abuse Bullying No known traumatic event Precipitating events Infection/viral infection Injury Post-surgery Major somatic history Asylum rejection Unknown 11 (46%) 9 (38%) 11 (46%) 4 (17%) 8 (33%) 7 (29%) 9 (38%) 15 (63%) 9 (38%) 7 (29%) 6 (25%) 5 (21%) 3 (13%) 3 (13%) 2 (8%) 1 (4%) 1 (4%) 1 (4%) 5 (21%) 9 (38%) 2 (8%) 1 (4%) 1 (4%) 1 (4%) 10 (42%) a Twenty-three patients from the literature search ? 1 patient from the Dutch article [25] expectation that responses are futile. The helplessness and hopelessness can transfer from parents to children and from children to parents as they watch one another struggling with uncontrollable events [18]. Other theories concerning the aetiology of PRS have been postulated, such as the psychodynamic theory of lethal mothering [4] and a possible neurobiological con- tribution of the insula [24]. Viral infections are often seen as precipitating factors (see Table 2). Von Folsach and Montgomery [27] proposed four important aetiologic factors: (1) a premorbid personality, (2) a history of child psychiatric problems, (3) parental psychiatric problems and (4) precipitating stressful events. Reviewing the literature, these four factors indeed seem to 123