Table 1

Potential predisposing, precipitating and perpetuating factors for FND (adapted from Stone50)

FactorsBiologicalPsychologicalSocial
Predisposing vulnerabilitiesIllness and disease.
History of previous functional symptoms.
Personality traits.
Poor attachment/coping style.
Emotional disorder.
Adverse life events or stressors.
Childhood neglect.
Difficulties in interpersonal relationships.
Symptom modelling.
Financial difficulties/deprivation.
Precipitating mechanismsPhysical injury or state (eg, drug side effect).
Abnormal physiological event (eg, hyperventilation and sleep paralysis).
Panic attack.
Perception of life event as traumatic/negative.
Adverse life events or stressors.
Perpetuating factorsPlasticity in sensory and motor pathways leading to abnormal movement patterns.
Deconditioning.
Fatigue.
Chronic pain.
Illness beliefs (person and significant others).
Feeling disbelieved.
Maladaptive behaviours.
Co-morbidities including anxiety and depression.
Diagnostic uncertainty (eg, ongoing medical investigations).
Reliance on care and benefits.
Compensation claims.
Ongoing social stressors (eg, relationship difficulties, financial hardship and loss of roles).