The early identification of psychosis: can lessons be learnt from cardiac stress testing?

Abstract

Psychotic disorders including schizophrenia are amongst the most debilitating psychiatric disorders. There is an urgent need to develop methods to identify individuals at risk with greater precision and as early as possible. At present, a prerequisite for a diagnosis of schizophrenia is the occurrence of a psychotic episode. Therefore, attempting to detect schizophrenia on the basis of psychosis is analogous to diagnosing coronary artery disease (CAD) after the occurrence of a myocardial infarction (MI). The introduction of cardiac stress testing (CST) has revolutionized the detection of CAD and the prevention and management of angina and MI. In this paper we attempt to apply lessons learnt from cardiac stress testing to the early detection of psychosis by proposing the development of an analogous psychosis stress test. We discuss in detail the various parameters of a proposed psychosis stress test including the choice of a suitable psychological or psychopharmacological “stressor”, target population, outcome measures, safety of the approach and the necessary evolution of test to become clinically informative. The history of evolution of CST may guide the development of a similar approach for the detection and management of psychotic disorders. The initial development of a test to unmask latent risk for schizophrenia will require the selection of a suitable and safe stimulus and the development of outcome measures as a prelude to testing in populations with a range of risk to determine predictive value. The use of cardiac stress testing in coronary artery disease offers the intriguing possibility that a similar approach may be applied to the detection and management of schizophrenia.

Basic self‐disturbance, neurocognition and metacognition: A pilot study among help‐seeking adolescents with and without attenuated psychosis syndrome

“…This possibility is supported by personal accounts, which indicate that acute episodes of SD are triggered or exacerbated by stress or emotional arousal. (Nelson & Sass, ; Parnas et al, ; Saks, ) Following a recommendation made by a recent theoretical paper (Gupta, Ranganathan, & D'souza, ), we believe that adding a stressful neuro‐metacognitive assessment condition would have yielded a stronger association between SD and metacognition.…”

“…A second possible explanation for the modest correlations relates to the different nature of the methods used to assess SD and neurometa-cognitive functioning. Although SD was assessed with a semistructured interview (EASE) that explores past experiences in which somatosensory and affective arousal usually play a significant (Nelson & Sass, 2009;Saks, 2008) Following a recommendation made by a recent theoretical paper (Gupta, Ranganathan, & D'Souza, 2016), we believe that adding a stressful neuro-metacognitive assessment condition would have yielded a stronger association between SD and metacognition.…”

Assessing the Relationship between Sense of Agency, the Bodily-Self and Stress: Four Virtual-Reality Experiments in Healthy Individuals

“…Analogous to cardiac patients that during rest exhibit an electrocardiogram similar to healthy controls and only under cardiac stress (i.e., walking on a treadmill) is their signal differentiable. Neurocognitive deficits during the at-risk phase may only be identifiable in a stressful environment that mimics the environment in which psychosis typically occurs [ 108 , 121 ]. Importantly, experiment 4 served as a pilot study to examine the effect of stress on neurocognitive capacities associated with the bodily-self in at-risk populations.…”