The lactate provocation test to investigate the relationships between panic attacks and delusional disorder: A two case report

Abstract

Background and aims

It was suspected that the delusional disorders of bewitchement and devil persecution of two female patients (41 and 40 years old) could be the consequence of an erroneous interpretation of the sensations induced by panic attacks, as several authors have previously suggested. Both patients had schizophrenia spectrum antecedents (Patient A was suffering from a schizo-affective disorder, Patient B had a schizotypic disorder and an antecedent of brief hallucinatory episode). Thus these individuals had some tendency toward psychotic thinking. The interest of this case report stems from the manner in which we tested our clinical hypothesis.

Methods

The patients agreed to the use of a lactate provocation test in double-blind, placebo-controlled conditions during four randomized sessions on consecutive days (two with lactate and two with placebo). The active lactate test used a 0.5 molar racemic lactate sodium 10 ml/kg solution, infused in 20 minutes.

Results

Neither patient displayed panic symptoms during the placebo sessions whereas patient A developed two full-blown panic attacks during the active lactate sessions and patient B developed one subthreshold and one moderate panic attack during the active lactate sessions. The results of these investigations led to a specific cognitive therapeutic treatment of the delusional convictions in patient A.

Conclusion

The results of this investigation, at least in patient A, strongly support our clinical hypothesis about a possible relationship between panic disorder and delusional disorder in some cases.