Original Research ARTICLE
Emotional Mental Imagery Abnormalities in Monozygotic Twins with, at High-Risk of, and without Affective Disorders: Present in Affected Twins in Remission but Absent in High-Risk Twins
- 1Centre for Psychiatry, Division of Brain Sciences, Imperial College London, United Kingdom
- 2Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, United Kingdom
- 3Copenhagen Affective Disorder Research Center, Region Hovedstad Psychiatry, Denmark
- 4Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Sweden
Background: Mental imagery abnormalities feature across affective disorders including bipolar disorder (BD) and unipolar depression (UD). Maladaptive emotional imagery has been proposed as a maintenance factor for affective symptomatology and a target for mechanism-driven psychological treatment developments. Where imagery abnormalities feature beyond acute affective episodes, further opportunities for innovation arise beyond treatments, such as for tertiary/relapse prevention (e.g., in remitted individuals) or primary prevention (e.g., in non-affected but at-risk individuals). The aim of our study was to investigate for the first time the presence of possible mental imagery abnormalities in affected individuals in remission and at-risk individuals for affective disorders using a familial risk design.
Methods: A population-based cohort of monozygotic twins was recruited through linkage between the Danish national registries (N=204). Participants were grouped as: affected (remitted BD/UD; n=115); high-risk (co-twin with history of BD/UD; n=49), or low-risk (no co-twin history of BD/UD; n=40). Twins completed mental imagery measures spanning key subjective domains (spontaneous imagery use and emotional imagery) and cognitive domains (imagery inspection and imagery manipulation).
Results: Affected twins in remission reported enhanced emotional mental imagery compared to both low- and high-risk twins. This was characterized by greater impact of (i) intrusive prospective imagery (Impact of Future Events Scale) and (ii) deliberately-generated prospective imagery of negative scenarios (Prospective Imagery Task). There were no significant differences in these key measures between affected BD and UD twins in remission. Additionally, low- and high-risk twins did not significantly differ on these emotional imagery measures. There were also no significant differences between the three groups on non-emotional measures including spontaneous imagery use and cognitive stages of imagery.
Conclusions: Abnormalities in emotional prospective imagery are present in monozygotic twins with affective disorders in remission - despite preserved cognitive stages of imagery - but absent in unaffected high-risk twins, and thus do not appear to index familial risk (i.e., unlikely to qualify as “endophenotypes”). Elevated emotional prospective imagery represents a promising treatment/prevention target in affective disorders.
Keywords: Mental Imagery, Future simulation, Bipolar Disorder, Depression, Twins, endophenotype
Received: 04 Jun 2019;
Accepted: 07 Oct 2019.
Copyright: © 2019 Di Simplicio, Lau-Zhu, Meluken, Taylor, Kessing, Vinberg, Holmes and Miskowiak. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Martina Di Simplicio, Centre for Psychiatry, Division of Brain Sciences, Imperial College London, London, England, United Kingdom, email@example.com