Papers by Natalia Jaworska
Tutorials in Quantitative Methods for Psychology, 2009
This paper aims to provide a non-technical overview of multidimensional scaling (MDS) so that a b... more This paper aims to provide a non-technical overview of multidimensional scaling (MDS) so that a broader population of psychologists, in particular, will consider using this statistical procedure. A brief description regarding the type of data used in MDS, its acquisition and analyses via MDS is provided. Also included is a commentary on the unique challenges associated with assessing the output of MDS. Our second aim, by way of discussing representative studies, is to highlight and evaluate the utility of this method in various domains in psychology.
Canadian Journal of Psychiatry Revue Canadienne De Psychiatrie, May 1, 2014
Journal of psychiatry & neuroscience : JPN, 2015
Pharmacology Biochemistry and Behavior, Feb 29, 2008
We assessed whether daily separation of Mongolian gerbils (Meriones unguiculatus) from mothers an... more We assessed whether daily separation of Mongolian gerbils (Meriones unguiculatus) from mothers and siblings during postnatal days 4-20 would produce behavioral and neurochemical changes in adulthood that parallel some features of depression in humans. Neonatal separation altered the behavior of adult females in the open field test but not in the tail suspension test, and did not affect behavior of males. Separated males, but not females, showed a significant decrease in hippocampal brain derived neurotrophic factor (BDNF) relative to controls. Western blot and optical densitometry measurements in the hippocampus did not reveal significant group differences in synaptophysin levels in either sex, but there was a tendency toward decreased levels of synaptophysin in the entire hippocampus as well as the CA1 hippocampal subregion of separated males. Repeated separation of neonates from mothers and siblings led to subtle behavioral and neurochemical changes during adulthood that were expressed differently in male and female gerbils.
Canadian journal of psychiatry. Revue canadienne de psychiatrie, 2013
Major depressive disorder (MDD) is primarily characterized by decreased affect and accompanying b... more Major depressive disorder (MDD) is primarily characterized by decreased affect and accompanying behavioural consequences, but it is also associated with cognitive dysfunction. Assessment of electroencephalographic (EEG) activity and associated event-related potentials (ERPs; derived from averaged EEG activity in response to a stimulus) in the context of MDD has provided insights into the electrocortical abnormalities associated with the disorder. Importantly, EEG and ERPs also have emerged as candidates for predicting and optimizing antidepressant (AD) treatment outcome. This is critical in light of relatively low remission rates or a limited response to initial AD interventions. In contrast to other neuroimaging approaches, EEG and ERPs may be superior for predicting and monitoring AD response, as electrocortical measures are relatively inexpensive, easy to use, and have excellent temporal (that is, millisecond) resolution, enabling fine-grained assessment of basic cognitive and em...
Canadian journal of psychiatry. Revue canadienne de psychiatrie, 2014
The relatively high prevalence of mental health problems among students at post-secondary institu... more The relatively high prevalence of mental health problems among students at post-secondary institutions in Canada is well documented; in contrast, less is known about the adequacy of mental health services available to Canadian post-secondary students on campuses. Our study sought to examine the current state of campus mental health initiatives and services in Alberta as well as the extent to which resources identified in mental health literature as being key in mental health problem prevention and promotion appear to be available. A 60-question, online survey was sent to staff (primarily front-line workers; n = 45) at Alberta's 26 publicly funded post-secondary institutions. Responses were organized according to small (less than 2000 students), medium (2000 to 10 000 students), and large (10 000 or more students) institutions. All of Alberta's post-secondary institutions were represented in the responses. Mental health initiatives and services are available, to varying exten...
Pharmacology Biochemistry and Behavior, 2008
We assessed whether daily separation of Mongolian gerbils (Meriones unguiculatus) from mothers an... more We assessed whether daily separation of Mongolian gerbils (Meriones unguiculatus) from mothers and siblings during postnatal days 4-20 would produce behavioral and neurochemical changes in adulthood that parallel some features of depression in humans. Neonatal separation altered the behavior of adult females in the open field test but not in the tail suspension test, and did not affect behavior of males. Separated males, but not females, showed a significant decrease in hippocampal brain derived neurotrophic factor (BDNF) relative to controls. Western blot and optical densitometry measurements in the hippocampus did not reveal significant group differences in synaptophysin levels in either sex, but there was a tendency toward decreased levels of synaptophysin in the entire hippocampus as well as the CA1 hippocampal subregion of separated males. Repeated separation of neonates from mothers and siblings led to subtle behavioral and neurochemical changes during adulthood that were expressed differently in male and female gerbils.
Brain Imaging and Behavior, 2014
The Canadian Journal of Psychiatry, 2016
Although the high prevalence of mental health issues among postsecondary students is well documen... more Although the high prevalence of mental health issues among postsecondary students is well documented, comparatively little is known about the adequacy, accessibility, and adherence to best practices of mental health services (MHSs)/initiatives on postsecondary campuses. We evaluated existing mental health promotion, identification, and intervention initiatives at postsecondary institutions across Canada, expanding on our previous work in one Canadian province. A 54-question online survey was sent to potential respondents (mainly front-line workers dealing directly with students [e.g., psychologists/counsellors, medical professionals]) at Canada's publicly funded postsecondary institutions. Data were analyzed overall and according to institutional size (small [<2000 students], medium [2000-10 000 students], large [>10 000 students]). In total, 168 out of 180 institutions were represented, and the response rate was high (96%; 274 respondents). Most institutions have some form of mental health promotion and outreach programs, although most respondents felt that these were not a good use of resources. Various social supports exist at most institutions, with large ones offering the greatest variety. Most institutions do not require incoming students to disclose mental health issues. While counselling services are typically available, staff do not reliably have a diverse complement (e.g., gender or race diversity). Counselling sessions are generally limited, and follow-up procedures are uncommon. Complete diagnostic assessments and the use of standardized diagnostic systems are rare. While integral MHSs are offered at most Canadian postsecondary institutions, the range and depth of available services are variable. These data can guide policy makers and stakeholders in developing comprehensive campus mental health strategies.
BMC Psychiatry, 2016
Major depressive disorder (MDD) is a multifaceted illness involving cognitive, emotional, and str... more Major depressive disorder (MDD) is a multifaceted illness involving cognitive, emotional, and structural brain changes; illness onset typically occurs in adolescence or young adulthood. Cortical thickness modulations may underlie, or accompany, functional brain activity changes in the prefrontal cortex (PFC) during emotional processing that tend to be observed in MDD. Thirteen unmedicated young adults with mild to moderate MDD, aged 18-24, completed a facial expression Go/No Go task and underwent a magnetic resonance imaging (MRI) scan to assess cortical thickness. Cortical thickness and performance on the Go/No Go task was also assessed in age-matched healthy comparison subjects (HCs; N = 14). Participants with depression had thicker left pars opercularis cortices than HCs. They also exhibited impaired response inhibition to neutral faces when responding only to sad faces, and a faster response time overall. Though our sample size is limited, this pilot study nevertheless provides evidence for cortical thickening in left frontal brain regions in a non-severely depressed, young adult group compared to healthy controls. There was also evidence of disturbances in emotion processing in this group.
BMC psychiatry, 2016
Structural brain abnormalities have been investigated in multi-genetic and complex disorders such... more Structural brain abnormalities have been investigated in multi-genetic and complex disorders such as major depressive disorder (MDD). Among the various candidate genes implicated in MDD, the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism and 5-HT transporter gene linked polymorphism (5-HTTLPR) have garnered the most attention due to their putative roles in neural plasticity and antidepressant response. However, relatively few studies have assessed the influence of these polymorphysims on cortical thickness or brain volume in para-limbic and limbic regions in MDD, which was the aim of this study. Forty-three adults with MDD and 15 healthy controls (HC) underwent structural magnetic resonance imaging (MRI). Cortical thickness was assessed in frontal, cingulate and temporal regions. Volumetric measures were carried out in the thalamus, caudate, putamen, pallidum, hippocampus and amygdala. Participants were genotyped to determine their 5-HTTLPR (tri-allelic) and Val66Met...
Psychiatry and Clinical Neurosciences, 2016
Structural, functional, and metabolic changes in the dorsolateral prefrontal cortex (DLPFC) are i... more Structural, functional, and metabolic changes in the dorsolateral prefrontal cortex (DLPFC) are implicated in the pathogenesis of major depressive disorder (MDD). We used proton magnetic resonance spectroscopy ((1) H-MRS) to examine the metabolite choline (glycerophosphocholine plus phosphocholine) which is used as an index of membrane integrity in the left DLPFC in adolescents and young adults with MDD, who were treatment-resistant and had a positive family history compared to healthy controls. Differences in the choline resonance indicate an imbalance between synthesis and degradation activity of neuronal and glia membrane phospholipids. Seventeen adolescents with MDD and eleven healthy controls underwent (1) H-MRS. A short echo PRESS (TE = 30 ms, TR = 2000 ms) protocol was used with a voxel (4.5 cc, 128 averages) placed within the left DLPFC. There were significantly increased choline (p = 0.04) and creatine concentrations (p = 0.005) in the left DLPFC of the MDD group compared to controls. In MDD participants, choline concentration correlated with scores on the Beck Depression Inventory (r = 0.41, p = 0.03). Increased left DLPFC choline and creatine levels in depressed adolescents may be biomarkers for the disorder. The increased choline levels may indicate abnormalities in neuronal membrane integrity, and the increased creatine could be reflective of altered energy demands and metabolism.
Journal of Affective Disorders, 2015
Many studies have reported that adults with recurrent major depressive disorder (MDD) have smalle... more Many studies have reported that adults with recurrent major depressive disorder (MDD) have smaller hippocampal volumes than control participants. The data are more variable in youth with MDD, where findings have been inconsistent and the effects of factors such as age and co-morbidity have not been systematically examined. This study therefore assessed hippocampus and subgenual anterior cingulate (sgACC) morphometry in 168 youth, aged 12-25, with or without MDD and comorbid anxiety. Structural magnetic resonance imaging (MRI) scans and clinical assessments were obtained from 80 participants with MDD (36 with comorbid anxiety disorder) and 88 age-matched control participants. Participants with MDD had smaller right hippocampi than controls (p=.013). Older depressed participants (20.1-25 years) had smaller hippocampal volumes than younger ones (<20.1 years; p=.05); this age effect was not apparent in controls (p=.46). Depression scores, indexed by the HAMD17, correlated with hippocampal volumes in older depressed youth. Depressed participants with comorbid anxiety had smaller sgACC, but not hippocampal, volumes than those without anxiety (p=.042). Longitudinal, versus cross-sectional, studies can most optimally assess the influence of depression on neurodevelopmental profiles. Though our participants were largely treatment-naïve or in their first week of pharmacotherapy, a handful had extensive treatment histories; thus, treatment history may have influenced brain morphometry. Age effects were apparent when hippocampal volumes of older and younger participants with MDD were compared; such differences were not apparent in healthy participants. Comorbid anxiety was associated with decreased sgACC volumes suggesting delayed or altered neurodevelopment in a key emotion regulation region.
BioMed Research International, 2014
Bipolar Disorders, 2014
The user has requested enhancement of the downloaded file. All in-text references underlined in b... more The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately.
European Psychiatry, 2014
The World Journal of Biological Psychiatry, 2014
Objectives. This review synthesized literature on brain activity, indexed by functional magnetic ... more Objectives. This review synthesized literature on brain activity, indexed by functional magnetic resonance imaging (fMRI), during visual affective information processing in major depressive disorder (MDD). Activation was examined in regions consistently implicated in emotive processing, including the anterior cingulate cortex (ACC), prefrontal cortex (PFC), amygdala, thalamus/basal ganglia and hippocampus. We also reviewed the effects of antidepressant interventions on brain activity during emotive processing. Methods. Sixty-four fMRI studies investigating neural activity during visual emotive information processing in MDD were included. Results. Evidence indicates increased ventro-rostral ACC activity to emotive stimuli and perhaps decreased dorsal ACC activity in MDD. Findings are inconsistent for the PFC, though medial PFC hyperactivity tends to emerge to emotive information processing in the disorder. Depressed patients display increased amygdala activation to negative and arousing stimuli. MDD may also be associated with increased activity to negative, and decreased activity to positive, stimuli in basal ganglia/thalamic structures. Finally, there may be increased hippocampus activation during negative information processing. Typically, antidepressant interventions normalize these activation patterns. Conclusion. In general, depressed patients have increased activation to emotive, especially negative, visual stimuli in regions involved in affective processing, with the exception of certain PFC regions; this pattern tends to normalize with treatment.
The Journal of ECT, 2014
Objective: We hypothesized an increase in dorsolateral prefrontal cortex (DLPFC) glutamate levels... more Objective: We hypothesized an increase in dorsolateral prefrontal cortex (DLPFC) glutamate levels would occur after 3 weeks of repetitive transcranial magnetic stimulation (rTMS) treatment and a decrease in major depressive disorder (MDD) symptoms.
Psychiatry Research: Neuroimaging, 2012
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Papers by Natalia Jaworska