During the past 60 years, perceptions about the origins of mental illness have shifted toward a biomedical model, depicting depression as a biological disorder caused by genetic abnormalities and/or chemical imbalances. Despite benevolent intentions to reduce stigma, biogenetic messages promote prognostic pessimism, reduce feelings of agency, and alter treatment preferences, motivations, and expectations. However, no research has examined how these messages influence neural markers of ruminative activity or decision-making, a gap this study sought to fill. In this pre-registered, clinical trial (NCT03998748), 49 participants with current or past depressive experiences completed a sham saliva test and were randomly assigned to receive feedback that they either have (gene-present; n = 24) or do not have (gene-absent; n = 25) a genetic predisposition to depression. Before and after receiving the feedback, resting-state activity and neural correlates of cognitive control (error-related negativity [ERN] and error positivity [Pe]) were measured using high-density electroencephalogram (EEG). Participants also completed self-report measures of beliefs about the malleability and prognosis of depression and treatment motivation. Contrary to hypotheses, biogenetic feedback did not alter perceptions or beliefs about depression, nor did it alter EEG markers of self-directed rumination nor neurophysiological correlates of cognitive control. Explanations of these null findings are discussed in the context of prior studies.
Keywords: Chemical imbalance; Depression; Error positivity; Error-related negativity; Etiological beliefs.
© 2023. The Psychonomic Society, Inc.