Table 2 A range of potential aetiological factors in patients with functional symptoms
FactorsBiologicalPsychologicalSocial
Acting at all stagesOrganic diseaseEmotional disorderSocioeconomic/deprivation
History of previous functional symptomsPersonality disorderLife events and difficulties
PredisposingGenetic factors affecting personalityPerception of childhood experience as adverseChildhood neglect/abuse
Biological vulnerabilities in the nervous system?Personality traitsPoor family functioning
Poor attachment/coping styleSymptom modelling (via media or personal contact)
PrecipitatingAbnormal physiological event or state (eg, hyperventilation, sleep deprivation, sleep paralysis)Perception of life event as negative, unexpected
Physical injury/painAcute dissociative episode/panic attack
PerpetuatingPlasticity in CNS motor and sensory (including pain) pathwaysDeconditioningIllness beliefs (patient and family)Perception of symptoms as being due to disease/damage/outwith the scope of self-helpThe presence of a welfare systemSocial benefits of being illAvailability of legal compensation
Neuroendocrine and immunological abnormalities similar to those seen in depression and anxietyNot feeling believedAvoidance of symptom provocation (eg, by learned conditioning)Stigma of “mental illness” in society and from medical professionOngoing medical investigations and uncertainty