Research Interests

Adverse events can occur and affect the brain at various stages, from gestation until adulthood. Such adverse events can affect the brain in many ways, including alterations in neurotransmission, brain structure, endocrinology, among others, 
all of which may interact. Given the important role of serotonin in brain development, alterations in the serotonin system as a result of early adverse events may be particularly relevant. My research program examines how early adversity, in combination with genetic factors, could affect the serotonin system in humans. The overarching hypothesis of my research program is that an early disruption in serotonin homeostasis could lower the vulnerability threshold in brain circuits involved in emotion regulation, thereby predisposing the individual to psychopathology when exposed to stressful events.
 
In my studies I use a combination of brain imaging, genetic, epigenetic (i.e. DNA methylation) and emotional-cognitive assessments. For instance, in ongoing projects, I investigate in prospectively followed community samples how early stressors could alter the expression of serotonin genes through epigenetic processes and impact the neural regulation of emotions. I am extending this line of research to clinical populations, in particular to individuals with mood disorders and to individuals with aggression problems.

Selected Publications

Wang, D., Szyf, M., Benkelfat, C., Provençal, N., Turecki, G., Caramaschi, D., Côté, S.M., Vitaro, F., Tremblay, R.E, Booij, L. (2012). Peripheral SLC6A4 DNA Methylation is associated with in vivo measures of human brain serotonin synthesis and childhood physical aggression. PlosOne, Epub 2012 Jun 20.

Booij, L., Wang, D., Lévesque, M.L.,Tremblay, R.E, Szyf, M. (2012). Looking beyond the DNA Sequence: The relevance of DNA methylation processes for the stress-diathesis model of depression. Phil Transactions of the Royal Society B, In press.

Booij, L., Turecki, G., Leyton, M., Gravel, P., Lopez De Lara, C., Diksic, M. & Benkelfat, C. (2012). Polymorphic variants in the TPH2 gene predict brain serotonin synthesis in humans. Molecular Psychiatry, 17, 809-817.

Booij, L., Benkelfat, C., Leyton, M., Vitaro, F., Gravel, P., Levesque, M.L., Arseneault, L., Diksic, M., Tremblay, R.E. (2012). Perinatal effects on in vivo measures of brain serotonin synthesis in adulthood: a 27 year longitudinal study. European Neuropsychopharmacology, 22, 419-423.

Caramaschi, D., Booij, L., Petitclerc, A., Boivin, M., Tremblay, R.E.(2012). Genetic and environmental contributions to saliva testosterone levels in male and female infant twins.  Psychoneuroendocrinology, May 7 [Epub ahead of print].

Van Steenbergen, H., Booij, L., Band, G.P.H., Hommel, B., Van der Does, A.J.W. (2012). Affective regulation of cognitive-control adjustments in remitted depressive patients after acute tryptophan depletion. Cognitive, Affective and Behavioral Neuroscience, 12, 280-286.

Lévesque M.L., Beauregard M., Fortier E., Tremblay R.E., Brendgen M., Pérusse D., Dionne G., Robaey P., Vitaro F., Boivin M., Booij L. (2011). Altered patterns of fronto-limbic activation in children with familial risk of depression. Journal of Affective disorders, 135, 410-413.

Booij, L., Tremblay, R.E., Leyton, M., Seguin, J.R., Vitaro, F., Gravel, P., Perreau-Linck, E., Levesque, M., Durand, F., Diksic, M., Turecki, G., & Benkelfat, C (2010). Brain serotonin synthesis in adult males characterized by physical aggression in childhood: A 21 year longitudinal study. PLoSONE, 5(6):e11255.

Booij, L., & Van der Does, A. J.W. (2007). Cognitive and serotonergic vulnerability to depression: Convergent findings. Journal of Abnormal Psychology, 116, 86-94.

Booij, L., Swenne, C. A., Brosschot, J. F., Haffmans, P. M. J., Thayer, J. F., & Van der Does, A. J. W. (2006).  Tryptophan depletion affects heart rate variability and impulsivity in remitted depressed patients with a history of suicidal ideation. Biological Psychiatry, 60, 507-514.

Booij, L., Merens, W., Markus C. R., & Van der Does, A. J. W. (2006). Diet rich in α-lactalbumin improves memory in unmedicated recovered depressed patients and matched controls. Journal of Psychopharmacology, 20, 526-535.

Booij, L., Van der Does, A. J. W., Haffmans, P. M. J, Riedel, W. J, Fekkes, D., & Blom, M. J. B. (2005). The effects of high-dose and low-dose tryptophan depletion on mood and cognitive functions of remitted depressed patients. Journal of Psychopharmacology, 19, 267-275.