Psychological Medicine

Original Articles

Psychological effects of chemical weapons: a follow-up study of First World War veterans

E. Jonesa1 c1, B. Everitta1, S. Ironsidea1, I. Palmera1 and S. Wesselya1

a1 Institute of Psychiatry and King's Centre for Military Health Research, Weston Education Centre, London, UK


Background Chemical weapons exercise an enduring and often powerful psychological effect. This had been recognized during the First World War when it was shown that the symptoms of stress mimicked those of mild exposure to gas. Debate about long-term effects followed the suggestion that gassing triggered latent tuberculosis.

Method A random sample of 103 First World War servicemen awarded a war pension for the effects of gas, but without evidence of chronic respiratory pathology, were subjected to cluster analysis using 25 common symptoms. The consistency of symptom reporting was also investigated across repeated follow-ups.

Results Cluster analysis identified four groups: one (n=56) with a range of somatic symptoms, a second (n=30) with a focus on the respiratory system, a third (n=12) with a predominance of neuropsychiatric symptoms, and a fourth (n=5) with a narrow band of symptoms related to the throat and breathing difficulties. Veterans from the neuropsychiatric cluster had multiple diagnoses including neurasthenia and disordered action of the heart, and reported many more symptoms than those in the three somatic clusters.

Conclusions Mild or intermittent respiratory disorders in the post-war period supported beliefs about the damaging effects of gas in the three somatic clusters. By contrast, the neuropsychiatric group did not report new respiratory illnesses. For this cluster, the experience of gassing in a context of extreme danger may have been responsible for the intensity of their symptoms, which showed no sign of diminution over the 12-year follow-up.

(Received June 15 2007)

(Revised December 07 2007)

(Accepted December 14 2007)

(Online publication February 01 2008)


c1 Address for correspondence: Professor E. Jones, Institute of Psychiatry and King's Centre for Military Health Research, Weston Education Centre, 10 Cutcombe Road, London SE5 9RJ, UK. (Email: