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Background Bipolar disorder (BD) is among the most heritable psychiatric disorders, particularly in early-onset cases, owing to multiple genes of small effect. Here we examine a multi-gene risk score (MGRS), to address the gap in multi-gene research in early-onset BD. Methods MGRS was derived from 34 genetic variants relevant to neuropsychiatric diseases and related systemic processes. Multiple MGRS were calculated across a spectrum of inclusion p-value thresholds, based on allelic associations with BD. Youth participants (123 BD, 103 healthy control [HC]) of European descent were included, of which 101 participants (58 BD, 43 HC) underwent MRI T1-weighted structural neuroimaging. Hierarchical regressions examined for main effects and MGRS-by-diagnosis interaction effects on 6 regions-of-interest (ROIs). Vertex-wise analysis also examined MGRS-by-diagnosis interactions. Results MGRS based on allelic association p≤0.60 was most robust, explaining 6.8% of variance (t(226)=3.46, p=.001). There was an MGRS-by-diagnosis interaction effect on ventrolateral prefrontal cortex surface area (vlPFC; β=.21, p=.0007). Higher MGRS was associated with larger vlPFC surface area in BD vs. HC. There were 8 significant clusters in vertex-wise analyses, primarily in fronto-temporal regions, including vlPFC. Limitations Cross-sectional design, modest sample size. Conclusions There was a diagnosis-by-MGRS interaction effect on vlPFC surface area, a region involved in emotional processing, emotional regulation, and reward response. Vertex-wise analysis also identified several clusters overlapping this region. This preliminary study provides an example of an approach to imaging-genetics that is intermediate between candidate gene and genome-wide association studies, enriched for genetic variants with established relevance to neuropsychiatric diseases.

The interindividual variability in opioid response is an issue that contributes to the ongoing opioid crisis. Current evidence suggests this variability can be attributed to genetic factors. The pharmacogenetics of Opioid Treatment for acute post-operative Pain (OTP) project was a prospective study that aimed to identify genetic markers associated with opioid treatment outcomes. Healthy patients undergoing third-molar extractions were recruited from dental offices located within the Greater Toronto Area. Participants were evaluated using the Brief Pain Inventory Short Form, the Opioid Related Symptom Distress Scale, and the Leeds Dependence Questionnaire. Seventy-two participants had an active opioid prescription. Participants were prescribed one of the following opioids: codeine, morphine, hydromorphone, tramadol, or oxycodone. The majority of participants were female (57%), ranging from 16 to 44 years of age. Pain severity, pain interference, and side effects declined over the seven-day post-operative period. Additionally, 4% of participants displayed medium to high risk of dependence. It is anticipated that OTP will enable the development of a genetic test for opioid use and facilitate the introduction of this test into routine healthcare practice. The OTP study represents a novel approach to opioid treatment and has significant implications for future interventions targeting the ongoing opioid crisis. Employing a pharmacogenomic-guided strategy for prescribing opioids may improve patients' response to this treatment and, in so doing, increase adherence to the target treatment plan. Optimized prescriptions may also provide public healthcare systems with beneficial savings and reduce the risks associated with opioid use.

Background Bipolar disorder (BD), among the most heritable psychiatric conditions, is associated with increased pro-inflammatory blood markers and pro-inflammatory gene expression in post-mortem brain. We therefore examined the effects of pro-inflammatory single nucleotide polymorphism interleukin-1β (IL-1β) rs16944 on brain structure in adolescents with BD and healthy control (HC) adolescents. Methods T1-weighted 3-T magnetic resonance imaging data were acquired for 38 adolescents with BD and 32 HC adolescents (14–20 years). Using FreeSurfer, a priori regions of interest analyses, examining hippocampus, amygdala, dorsolateral prefrontal cortex (DLPFC), and caudal anterior cingulate cortex, were complemented by exploratory whole-brain vertex-wise analyses. General linear models assessed the association between IL-1β rs16944 and the ROIs, controlling for sex, age, and intracranial volume. Results There was an IL-1β rs16944 polymorphism-by-diagnosis interaction effect on the DLPFC; T-carriers with BD had greater surface area compared to non-carriers with BD. Whereas, HC T-carriers had smaller DLPFC volume compared to HC non-carriers. In vertex-wise analyses, similar interactions were evident in a pars triangularis surface area cluster and a lateral occipital cortex volume cluster. Whole-brain analyses also yielded a main effect of IL-1β rs16944 polymorphism, whereby T-carriers had greater lateral occipital cortex surface area and volume. Conclusions The IL-1β rs16944 polymorphism is associated with neurostructural phenotypes in cognitive and visual regions that subserve functions, including facial recognition and response inhibition, which are known to be aberrant in BD. Future studies are warranted to evaluate whether the observed rs16944-related structural differences are relevant to neurocognitive function, functional neuroimaging phenotypes and IL-1β protein levels.

Individuals carrying genetic variants that result in non-extensive CYP2D6 and CYP2C19 enzyme activity seem to be more prone to non-response and side-effects of psychotropic medications. Therefore, tailoring prescriptions using genetic information may improve patient outcomes. This study examined treatment outcome in psychiatric care after CYP2D6 and CYP2C19 genetic information was provided to patients and physicians. CYP2D6 and CYP2C19 genotyping, assessment of side effects and medical histories were obtained from 80 subjects who were prescribed either antidepressant or antipsychotic medications. Our measure of outcome was mainly physicians' opinions however UKU side effects scores were also used. For CYP2D6, we calculated an activity score based on genotype and psychiatric medications. Correlation analysis was performed for CYP2D6 activity scores and UKU scores. Overall, we received supportive responses from physicians who enrolled patients in our study. Notably, while almost every fourth physician reported improvement in patient outcome, not a single physician indicated that their patient's symptoms worsened after they had used a pharmacogenetic report to guide treatment. We did not observe statistically significant differences in side effects. Overall, our results suggest improved patient outcome following pharmacogenetic testing; nonetheless, more research is required to assess the exact benefit of pharmacogenetics in clinical practice.

Suicide claims over 800,000 lives each year worldwide. Suicide rates in indigenous populations in Canada are about double that of the national average, making it a serious public health issue. Numerous factors are involved in suicide risk, including genetic factors, as well as various psychosocial stressors, such as historical experience with the Indian Residential School system for Indigenous populations, as well as protective variables such as social support. Here, we report the first genetic study of suicidal behaviors that includes multiple measures of stress and social supports. We investigated the role of the functional Val66Met marker (rs6265) in the Brain-Derived Neurotropic Factor (BDNF) gene in suicidal ideation and suicide attempt in a First Nations community sample (N = 278). We did not find a significant association between the BDNF rs6265 marker and suicidal behaviors. We found childhood adversities, recent life stress, chronic stress, perceived stress, difficulties, and hazardous alcohol use to be associated with both suicidal ideation and suicide attempt. Thus, while additional studies with larger samples are required to elucidate the genetic component of suicide, addressing environmental stressors may be important for suicide prevention.

Objective Investigate the effects of CACNA1C rs1006737 on cortical and subcortical neurostructural phenotypes in Caucasian bipolar disorder (BD) and healthy control (HC) adolescents. Methods Seventy-one adolescents (14–20 years; 38BD, 33HC) underwent 3-Tesla Magnetic Resonance Imaging (MRI). Region of interest (ROI) and vertex-wise analyses examined cortical volume, surface area (SA), and thickness, as well as subcortical volume. ROIs included the ventromedial prefrontal cortex (vmPFC), ventrolateral prefrontal cortex (vlPFC), anterior cingulate cortex (ACC), putamen, and amygdala. General linear models included main effects of diagnosis and rs1006737, and an interaction term, controlling for age, sex, and total intracranial volume. Results Vertex-wise analysis found significant BD-by-rs1006737 interactions for prefrontal and occipital regions such that BD A-carriers were found to have greater SA relative to BD non-carriers, while HC A-carriers had reduced SA relative to HC non-carriers. ROI analysis found an interaction in the ACC such that BD A-carriers were found to have greater SA relative to BD non-carriers, while no significant difference was found in HCs. Main effects of rs1006737 were also found on ACC SA from ROI analysis, and occipital SA from vertex-wise analysis, such that A-carriers had larger SA relative to non-carriers in both of these regions. Conclusions The current study identified neurostructural intermediate phenotypes relevant to the impact of CACNA1C rs1006737 on adolescent BD. Further investigation is warranted into the neurofunctional and neurocognitive relevance of rs1006737 associations with BD-specific elevations in regional SA.

Background The current process used to prescribe antidepressant medication is markedly inefficient, as more than 50% of treated patients fail to reach remission. Antidepressant treatment success has been associated with genetic variation, but studies are not well replicated and epigenetic mechanisms remain under investigated. DNA methylation may provide more information regarding antidepressant response and guide physicians in choosing the most effective medication for each patient. We investigated the influence of SLC6A4 methylation and 5-HTTLPR genotypes on antidepressant response in our sample. Methods A subset of depression patients with complete clinical data (European Caucasian, n=166), were selected from our discovery sample (IMPACT; N=8,000). Saliva samples were collected at enrollment and genetic testing was done of cytochrome P450 liver enzyme, 5HTTLPR and 5HT2A variants to guide clinical choice and dosage of psychotropic medications. As such, a significant component of our sample includes treatment refractory, as well as medication intolerant patients. DNA was bisulfite converted and methylation profiles were interrogated using the Infinium HumanMethylation450 Beadchip array. Nine CpG probes located across the SLC6A4 promoter region were selected, based on previous studies, to quantify methylation levels. Change in Beck Depression Inventory II (BDI-II) score was used to measure antidepressant response over eight weeks. The relationship among genotype, methylation levels, and antidepressant response was analysed using linear regression modeling. Results Increased methylation in the promoter region of the SLC6A4 gene was nominally associated with impaired response to antidepressants in our sample. The effect was driven by methylation site cg05016953, located in exon 1 A. Increased methylation level as measured by CpG cg05016953 was associated with less improvement in BDI-II score over eight weeks of antidepressant treatment (F(3,163)=6.14, puncorr=0.012). 5-HTTLPR genotype was not associated with SLC6A4 DNA methylation or antidepressant treatment response. Discussion An increase in SLC6A4 DNA methylation at cg05016953 may be associated impaired response to antidepressant medications in our sample. The SLC6A4 transcriptional control region contains a CpG island, previously shown to functionally influence mRNA levels depending on 5-HTTLPR genotypes. Typically, hypermethylation in promoter regions is associated with decreased gene expression. Theoretically, hypermethylation of the 5-HTT promoter would reduce the number of serotonin transporters, and reduce serotonin re-uptake, which in simple terms should improve response to SSRI treatment. Further pharmaco-epigenetic studies are required to elucidate the effect of DNA methylation changes on antidepressant response.

Background Suicidal behaviour can be a serious symptom of psychiatric disorder and may change during the course of psychotropic medication treatment. There have been a number of published Genome-Wide Association Studies (GWASs) of treatment-emergent suicidal ideation, but there has not been GWAS of resolution of suicidal ideation during drug treatment. Here we report on two such GWASs. Methods From the STEP-BD study, we have 450 patients with bipolar disorder assessed on the MADRS. We analyzed the change in suicidality from baseline to six months. From the IMPACT study (Individualized Medicine: Pharmacogenetic Assessment & Clinical Treatment), we have 118 participants suffering from anxiety, depression, bipolar disorder, and/or attention-deficit hyperactivity disorder. They were genotyped on the Illumina Omni 2.5 M chip and were followed for eight weeks on the Beck Depression Inventory. Of these participants, 69 experienced suicidal ideation at baseline, and 23 of them did not experience suicidal ideation at their eight-week study visit. Conversely, 49 participants did not have suicidal ideation at baseline, of which six reported suicidal ideation at the eight-week visit. We analyzed the change in suicidal ideation during these studies, including baseline suicidality scores, age, and sex as covariates. Results We did not observe genome-wide significant findings from either GWAS. We observed a possible genetic overlap between suicidal ideation in the STEP-BD bipolar disorder sample and suicidal ideation in the IMPACT sample (p=0.047). Discussion Suicide is a clinically important phenotype in clinical studies. Investigating the increases as well as decreases in suicidal ideation during psychotropic medication may be an interesting avenue for further genetic investigations.

Tardive dyskinesia (TD) is an involuntary movement disorder that can occur in up to 25% of patients receiving long-term first-generation antipsychotic treatment. Its etiology is unclear, but family studies suggest that genetic factors play an important role in contributing to risk for TD. The vesicular monoamine transporter 2 (VMAT2) is an interesting candidate for genetic studies of TD because it regulates the release of neurotransmitters implicated in TD, including dopamine, serotonin, and GABA. VMAT2 is also a target of tetrabenazine, a drug used in the treatment of hyperkinetic movement disorders, including TD. We examined nine single-nucleotide polymorphisms (SNPs) in the SLC18A2 gene that encodes VMAT2 for association with TD in our sample of chronic schizophrenia patients (n = 217). We found a number of SNPs to be nominally associated with TD occurrence and the Abnormal Involuntary Movement Scale (AIMS), including the rs2015586 marker which was previously found associated with TD in the CATIE sample (Tsai et al., 2010), as well as the rs363224 marker, with the low-expression AA genotype appearing to be protective against TD (p = 0.005). We further found the rs363224 marker to interact with the putative functional D2 receptor rs6277 (C957T) polymorphism (p = 0.001), supporting the dopamine hypothesis of TD. Pending further replication, VMAT2 may be considered a therapeutic target for the treatment and/or prevention of TD.

Background A recent genome-wide association study (GWAS) of antidepressant response in obsessive-compulsive disorder (OCD) reported a genome-wide significant marker in the dispatched homolog 1 (Drosophila) gene (DISP1). This gene encodes for a protein that is important for spinal cord development. Methods In this study, we attempted to replicate this finding by investigating the DISP1 rs17162912 polymorphism in 359 OCD patients with serotonin reuptake inhibitor (SRI: fluoxetine, paroxetine, fluvoxamine, sertraline, citalopram, and clomipramine) antidepressant response data. SRI response was defined categorically as responder ("very much" and "much" improved) and non-responder ("minimal" improvment, "no change", or "worse") using the Clinical Global Impression – Improvement (CGI-I) scale and Pearson chi-squared test was performed between the genotype distribution and SRI response status. Results We did not observe significant association between the DISP1 rs17162912 (P=0. 470) with SRI response. Discussion This study did not provide support for a role of the DISP1 rs17162912 in predicting SRI response in OCD patients. Future investigation of the region of DISP1 may provide further insight into whether it contributes to SRI response in patients with OCD. Financial Relationships I (or my spouse/partner) do have potential conflicts of interest to disclose.