Background: A confounding factor in the diagnosis of adverse drug reactions (ADRs) is the psychological state of the patient. Patients with underlying anxiety and related disorders may present with psychogenic reactions, which involve physiologic responses originating from psychological, rather than organic factors.
Objective: To examine the contribution of anxiety and related disorders to adverse drug events.
Methods: Participants from an adverse drug reaction clinic completed the Trauma Symptom Checklist-40 (TSC-40), a 40-item questionnaire consisting of six subscales: anxiety, depression, dissociation, sexual abuse trauma index (SATI), sexual problems, and sleep disturbance. Physicians assessed the likelihood that adverse events were due to anxiety or drug(s) by providing an anxiety score (0 to 10) and an ADR score (0 to 10), respectively, for each participant.
Results: Patients clinically assessed as having "high anxiety" (anxiety score 7-10 and ADR score 0-3; n = 11) scored higher than patients clinically assessed as having a "true ADR" (anxiety score 0-3 and ADR score 7-10; n = 19) on the TSC-40 total (P = 0.006) as well as anxiety (P = 0.012), depression (P = 0.007), and SATI subscales (P = 0.016).
Conclusion: This study is the first to use a validated psychological measurement to indicate that a substantial percentage of reported adverse drug events may in fact be a manifestation of underlying anxiety and/or related disorders. We suggest that mechanisms of symptom generation may be analogous to those operative in idiopathic environmental intolerance.