J Psychiatry Neurosci 2015;40(5):336-343
Nicolas Berthelot, PhD; Thomas Paccalet, PhD; Elsa Gilbert, PhD; Isabel Moreau, MSc; Chantal Mérette, MD; Nathalie Gingras, MD; Nancie Rouleau, PhD; Michel Maziade, MD
Background: Millions of children are born to parents affected by major psychoses. Cognitive dysfunctions seen in patients are already detectable in these children. In parallel, childhood maltreatment increases the risk of adult psychoses through unknown mechanisms. We investigated whether high-risk offspring exposed to abuse/neglect displayed more cognitive precursors of adult psychoses in childhood and adolescence than nonexposed offspring.
Methods: We used a stepwise selection strategy from a 25-year follow-up of 48 densely affected kindreds including 1500 adults (405 patients with schizophrenia or bipolar disorder) to select high-risk offspring aged 6–22 years for inclusion in our study. All offspring were assessed for childhood trauma from direct interviews with the offspring, parents and relatives and from the review of lifetime medical records of parents and children and administered a neuropsychological battery including IQ and 4 of the most impaired neuropsychological domains in psychoses.
Results: Our study included 66 high-risk offspring. Those who were exposed to abuse/neglect had significantly lower IQ (effect size [ES] = 0.61) than nonexposed offspring and displayed poorer cognitive performance in visual episodic memory (ES = 0.67) and in executive functions of initiation (ES = 1.01). Moreover, exposed offspring presented more combinations of cognitive deficits that were associated with lower Global Assessment of Functioning scores.
Limitations: Exposure to abuse/neglect was not assessed in the control group, thus the study could not test whether the effect of childhood maltreatment occured only in a high-risk setting and not in the general population.
Conclusion: In high-risk youths, maltreatment in childhood/adolescence may negatively impact cognitive domains known to be impaired in adults with psychoses, suggesting an early mediating effect in the association between abuse/neglect and adult psychoses. This finding provides a target for future developmental and preventive research.
Submitted Aug. 1, 2014; Accepted Jan. 9, 2015; Early-released June 2, 2015.
Acknowledgments: We thank our research assistants, M.-C. Boisvert, L. Bélanger, J. Lavoie, L. René, V. Beaupré-Monfette, C. Poirier and V. Jomphe, and the families who participated in this study. This study was supported by a Canada Research Chair (#950-200810) in psychiatric genetics (M. Maziade) and by Canadian Institute of Health Research grants (#MOP-74430, #MOP-114988 and #MOP-119408). The funding organizations had no role in the writing of this manuscript.
Affiliations: From the Department of Clinical and Cognitive Neuroscience, Centre de recherche de l’Institut universitaire en santé mentale de Québec, Québec, Canada (Berthelot, Paccalet, Gilbert, Moreau, Mérette, Gingras, Rouleau, Maziade); the Faculty of Nursing, Université du Québec à Trois-Rivières, Trois-Rivières, Canada (Berthelot); and the Departments of Psychiatry (Mérette, Gingras, Maziade) and Psychology (Rouleau), Université Laval, Québec, Canada.
Competing interests: None declared.
Contributors: N. Berthelot, T. Paccalet and M. Maziade designed the study. N. Berthelot, E. Gilbert, N. Gingras, N. Rouleau and M. Maziade acquired the data, which N. Berthelot, T. Paccalet, I. Moreau, C. Mérette and M. Maziade analyzed. N. Berthelot, T. Paccalet and M. Maziade wrote the article, which all authors reviewed and approved for publication.
Correspondence to: M. Maziade, Centre de recherche de l’Institut universitaire en santé mentale de Québec, 2601 de la Canardière, Québec, QC G1J 2G3; firstname.lastname@example.org