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This nonrandomized, multicenter, open-label clinical trial explored the impact of intravenous (IV) ketamine on cognitive function in adults (n = 74) with treatment-resistant depression (TRD). Patients received three IV ketamine infusions during the acute phase and, if remitted, four additional infusions in the continuation phase (Mayo site). Cognitive assessments using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) were conducted at baseline, end of the acute phase, and end of the continuation phase (Mayo site). Results showed a significant 53 % (39/74) remission rate in depression symptoms after the acute phase. In adjusted models, baseline language domain score was associated with a higher odd of remission (Odds Ratio, 1.09, 95 % CI = 1.03-1.17, p = 0.004) and greater improvement in MADRS at the end of the acute phase (ß =-0.97; 95 % CI, -1.74 to -0.20; P = 0.02). The likelihood of remission was not significantly associated with baseline immediate or delayed memory, visuospatial/constructional, or attention scores. In the continuation phase, improvements in immediate and delayed memory and attention persisted, with additional gains in visuospatial and language domains. Limitations included an open-label design, potential practice effects, and ongoing psychotropic medication use. Overall, the study suggests cognitive improvement, not deterioration, associated with serial IV ketamine administrations for TRD. These findings encourage future studies with larger sample sizes and longer follow-up periods to examine any potential for deleterious effect with recurrent ketamine use for TRD. Trial Registration: ClinicalTrials.gov: NCT03156504.
Subject(s)
Depressive Disorder, Treatment-Resistant , Ketamine , Adult , Humans , Depression , Depressive Disorder, Treatment-Resistant/drug therapy , Depressive Disorder, Treatment-Resistant/psychology , Infusions, Intravenous , Ketamine/pharmacology , Ketamine/therapeutic use , Remission InductionABSTRACT
Introduction: Emerging literature suggests that childhood trauma may influence facial emotion perception (FEP), with the potential to negatively bias both emotion perception and reactions to emotion-related inputs. Negative emotion perception biases are associated with a range of psychiatric and behavioral problems, potentially due or as a result of difficult social interactions. Unfortunately, there is a poor understanding of whether observed negative biases are related to childhood trauma history, depression history, or processes common to (and potentially causative of) both experiences. Methods: The present cross-sectional study examines the relation between FEP and neural activation during FEP with retrospectively reported childhood trauma in young adult participants with remitted major depressive disorder (rMDD, n = 41) and without psychiatric histories (healthy controls [HC], n = 34). Accuracy of emotion categorization and negative bias errors during FEP and brain activation were each measured during exposure to fearful, angry, happy, sad, and neutral faces. We examined participant behavioral and neural responses in relation to total reported severity of childhood abuse and neglect (assessed with the Childhood Trauma Questionnaire, CTQ). Results: Results corrected for multiple comparisons indicate that higher trauma scores were associated with greater likelihood of miscategorizing happy faces as angry. Activation in the right middle frontal gyrus (MFG) positively correlated with trauma scores when participants viewed faces that they correctly categorized as angry, fearful, sad, and happy. Discussion: Identifying the neural mechanisms by which childhood trauma and MDD may change facial emotion perception could inform targeted prevention efforts for MDD or related interpersonal difficulties.
Subject(s)
Bipolar Disorder , Humans , Bipolar Disorder/epidemiology , Longitudinal Studies , Risk FactorsABSTRACT
BACKGROUND: Childhood trauma is commonly experienced by individuals diagnosed with bipolar disorder (BP). In BP, childhood trauma is related to a more severe clinical course, but its association with cognition remains unclear. METHODS: This study evaluated 405 adult participants diagnosed with BP and 136 controls. Participants completed the Childhood Trauma Questionnaire and a comprehensive neuropsychological battery. High versus low childhood trauma was defined with one standard deviation above the control participant's mean Childhood Trauma Questionnaire score. Neuropsychological data was transformed into eight cognitive factors, including four executive functioning, auditory and visual memory, fine motor, and emotion processing. Multivariate analysis of covariance evaluated group differences in cognition, while adjusting for covariates. RESULTS: There were significant differences among the three groups, F(16, 968) = 4.05, p < .001, Wilks' Λ = 0.88, partial η2 = 0.06. Comparing the high and low trauma BP groups, high trauma was related to lower auditory and visual memory factor scores (p < .05). As compared to controls, the BP high trauma group had lower scores on six of eight factors (all p < .01), while the BP low trauma group had lower scores on four of eight factors (all p < .01). LIMITATIONS: Analyses of factor score do not address which aspect of the memory process is affected and biomarkers may help guide interventions addressing underlying biological process. CONCLUSIONS: Adults diagnosed with BP with higher childhood trauma have worse memory functioning, beyond the lower childhood trauma BP group, highlighting the importance of understanding the long-term cognitive outcomes of childhood trauma.
Subject(s)
Adverse Childhood Experiences , Bipolar Disorder , Adult , Humans , Bipolar Disorder/complications , Bipolar Disorder/psychology , Neuropsychological Tests , Memory , Executive Function , Cognition , Memory Disorders/complicationsABSTRACT
Lithium (Li) is one of the most effective drugs for treating bipolar disorder (BD), however, there is presently no way to predict response to guide treatment. The aim of this study is to identify functional genes and pathways that distinguish BD Li responders (LR) from BD Li non-responders (NR). An initial Pharmacogenomics of Bipolar Disorder study (PGBD) GWAS of lithium response did not provide any significant results. As a result, we then employed network-based integrative analysis of transcriptomic and genomic data. In transcriptomic study of iPSC-derived neurons, 41 significantly differentially expressed (DE) genes were identified in LR vs NR regardless of lithium exposure. In the PGBD, post-GWAS gene prioritization using the GWA-boosting (GWAB) approach identified 1119 candidate genes. Following DE-derived network propagation, there was a highly significant overlap of genes between the top 500- and top 2000-proximal gene networks and the GWAB gene list (Phypergeometric = 1.28E-09 and 4.10E-18, respectively). Functional enrichment analyses of the top 500 proximal network genes identified focal adhesion and the extracellular matrix (ECM) as the most significant functions. Our findings suggest that the difference between LR and NR was a much greater effect than that of lithium. The direct impact of dysregulation of focal adhesion on axon guidance and neuronal circuits could underpin mechanisms of response to lithium, as well as underlying BD. It also highlights the power of integrative multi-omics analysis of transcriptomic and genomic profiling to gain molecular insights into lithium response in BD.
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OBJECTIVE: Assessing performance validity is imperative in both clinical and research contexts as data interpretation presupposes adequate participation from examinees. Performance validity tests (PVTs) are utilized to identify instances in which results cannot be interpreted at face value. This study explored the hit rates for two frequently used PVTs in a research sample of individuals with and without histories of bipolar disorder (BD). METHOD: As part of an ongoing longitudinal study of individuals with BD, we examined the performance of 736 individuals with BD and 255 individuals with no history of mental health disorder on the Test of Memory Malingering (TOMM) and the California Verbal Learning Test forced choice trial (CVLT-FC) at three time points. RESULTS: Undiagnosed individuals demonstrated 100% pass rate on PVTs and individuals with BD passed over 98% of the time. A mixed effects model adjusting for relevant demographic variables revealed no significant difference in TOMM scores between the groups, a = .07, SE = .07, p = .31. On the CVLT-FC, no clinically significant differences were observed (ps < .001). CONCLUSIONS: Perfect PVT scores were obtained by the majority of individuals, with no differences in failure rates between groups. The tests have approximately >98% specificity in BD and 100% specificity among non-diagnosed individuals. Further, nearly 90% of individuals with BD obtained perfect scores on both measures, a trend observed at each time point.
Subject(s)
Bipolar Disorder , Humans , Neuropsychological Tests , Longitudinal Studies , Malingering/diagnosis , Malingering/psychology , Memory and Learning Tests , Reproducibility of ResultsABSTRACT
INTRODUCTION: Understanding how Bipolar Disorder (BD) affects employment is limited by cross-sectional or short-term longitudinal designs. The aims for this study are to examine condition-related and other clinical predictors of longitudinal employment status and stability in those with BD compared to healthy controls (HC). METHODS: Participants were 358 individuals with BD and HC who were enrolled in the Heinz C. Prechter Longitudinal Study of BD. Participants completed self-report measurements of employment, symptoms, health, personality, life events, and neuropsychological tests at study enrollment, yearly and/or every two months. Repeated measures logistic regression was used to predict employment status and stability. RESULTS: Those with BD were less likely to be employed than HC. Significant predictors of unemployment in BD include having BD type I, younger age, less years with BD, higher depression, worse processing speed, and worse mental and physical health. Of those with BD, 64 % demonstrated greater employment instability compared to 37 % of HC. History of psychosis, worse memory, physical health, and greater disruption of negative life events significantly predicted employment instability. LIMITATIONS: The limitations of this study include the generalizability of this sample, a large reliance of self-report measures, and a lack of employment-related factors such as job-type, functioning, performance, and satisfaction. Lastly, the effects of medication, treatment adherence, and treatment optimization were not assessed in this study. CONCLUSIONS: These findings highlight that different aspects of BD are important for being employed versus maintaining stable employment. These findings indicate the need for more effective treatment strategies beyond symptom management.
Subject(s)
Bipolar Disorder , Humans , Bipolar Disorder/epidemiology , Bipolar Disorder/psychology , Longitudinal Studies , Cross-Sectional Studies , Neuropsychological Tests , Employment/psychologyABSTRACT
The Life Goals (LG) application is an evidence-based self-management tool intended to help individuals with bipolar disorder (BD) by aligning symptom coping strategies with personal goals. The program has traditionally been offered in-person or via the web, but has recently been translated into an individualized, customizable mobile intervention to improve access to care and reduce provider burden. The LG app previously showed acceptability with ease of use and satisfaction with user interface, but less success in encouraging self-management. To better understand patient needs, our team conducted semi-structured interviews with 18 individuals with BD who used the LG app for 6 months. These interviews also investigated participant interest in sharing LG app data with their provider through an online dashboard. Using affinity mapping, a collaborative, qualitative data analysis technique, our team identified emerging common themes in the interviews. Through this process, team members identified 494 pieces of salient information from interviews that were mapped and translated into three main findings: (1) many participants found Mood Monitoring and LG modules helpful/interesting and stated the app overall had positive impacts on their mental health, (2) some components of the app were too rudimentary or impersonal to be beneficial, and (3) feedback was mixed regarding future implementation of an LG provider dashboard, with some participants seeing potential positive impacts and others hesitating due to perceived efficacy and privacy concerns. These findings can help researchers improve app-based interventions for individuals with BD by increasing app usage and improving care overall.
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INTRODUCTION: Cognitive functioning in bipolar disorder is heterogeneous with evidence for multiple subgroups. However, cognitive subgroup change patterns over time remains unknown. While prior work suggests minimal differences in cognitive functioning patterns over time between those with bipolar disorder and controls, group-based analyses may obscure unique subgroup-based changes. MATERIAL AND METHODS: Participants diagnosed with bipolar disorder (I, II, NOS; n = 568) and unaffected controls (n = 234) completed baseline, one- and five-year neuropsychological assessments. Data reduction techniques were used to limit the number of neuropsychological variables. Bipolar disorder participant baseline neuropsychological data were entered into hierarchical cluster analyses and resultant clusters were entered in multilevel models, which tested for differences in baseline and longitudinal cognitive changes in cognition among the cluster groups and with controls. RESULTS: Results were consistent with bipolar disorder participants forming three subgroups with high (n = 209), mid (n = 259), and low (n = 100) cognition. These groups were associated with unique clinical characteristics. Multilevel models demonstrated that over a five-year period, the low group improved, relative to the high and mid groups, and with controls, in auditory memory. Over the five-year period, the mid group, in comparison with the high group, improved in visual memory; additionally, the high group remained stable, in comparison with a slight decline in the control group, in inhibitory control. CONCLUSION: These results demonstrate that cognition-based subgroups of bipolar disorder participants have minimal differences in their longitudinal course in relation to each other and with unaffected controls.
Subject(s)
Bipolar Disorder , Cognition Disorders , Bipolar Disorder/psychology , Cognition , Cognition Disorders/psychology , Humans , Longitudinal Studies , Neuropsychological TestsABSTRACT
OBJECTIVES: Previous research suggests that cognitive performance worsens during manic and depressed states in bipolar disorder (BD). However, studies have often relied upon between-subject, cross-sectional analyses and smaller sample sizes. The current study examined the relationship between mood symptoms and cognition in a within-subject, longitudinal study with a large sample. METHODS: Seven hundred and seventy-three individuals with BD completed a neuropsychological battery and mood assessments at baseline and 1-year follow-up. The battery captured eight domains of cognition: fine motor dexterity, visual memory, auditory memory, emotion processing, and four aspects of executive functioning: verbal fluency and processing speed; conceptual reasoning and set shifting; processing speed with influence resolution; and inhibitory control. Structural equation modeling was conducted to examine the cross-sectional and longitudinal relationships between depressive symptoms, manic symptoms, and cognitive performance. Age and education were included as covariates. Eight models were run with the respective cognitive domains. RESULTS: Baseline mood positively predicted 1-year mood, and baseline cognition positively predicted 1-year cognition. Mood and cognition were generally not related for the eight cognitive domains. Baseline mania was predictive in one of eight baseline domains (conceptual reasoning and set shifting); baseline cognition predicted 1-year symptoms (inhibitory control-depression symptoms, visual memory-manic symptoms). CONCLUSIONS: In a large community sample of patients with bipolar spectrum disorder, cognitive performance appears to be largely unrelated to depressive and manic symptoms, suggesting that cognitive dysfunction is stable in BD and is not dependent on mood state in BD. Future work could examine how treatment affects relationship between cognition and mood. SIGNIFICANT OUTCOMES: Cognitive dysfunction appears to be largely independent of mood symptoms in bipolar disorder. LIMITATIONS: The sample was generally highly educated (M = 15.22), the majority of the subsample with elevated manic symptoms generally presented with concurrent depressive elevated symptoms, and the study did not stratify recruitment based on mood state.
Subject(s)
Bipolar Disorder , Cognition Disorders , Bipolar Disorder/psychology , Cognition , Cognition Disorders/psychology , Cross-Sectional Studies , Humans , Longitudinal Studies , Neuropsychological TestsABSTRACT
BACKGROUND: Bipolar disorder (BD) is characterized by episodes of depression and mania and disrupted circadian rhythms. Lithium is an effective therapy for BD, but only 30%-40% of patients are fully responsive. Preclinical models show that lithium alters circadian rhythms. However, it is unknown if the circadian rhythm effects of lithium are essential to its therapeutic properties. METHODS: In secondary analyses of a multi-center, prospective, trial of lithium for BD, we examined the relationship between circadian rhythms and therapeutic response to lithium. Using standardized instruments, we measured morningness, diurnal changes in mood, sleep, and energy (circadian rhythm disturbances) in a cross-sectional study of 386 BD subjects with varying lithium exposure histories. Next, we tracked symptoms of depression and mania prospectively over 12 weeks in a subset of 88 BD patients initiating treatment with lithium. Total, circadian, and affective mood symptoms were scored separately and analyzed. RESULTS: Subjects with no prior lithium exposure had the most circadian disruption, while patients stable on lithium monotherapy had the least. Patients who were stable on lithium with another drug or unstable on lithium showed intermediate levels of disruption. Treatment with lithium for 12 weeks yielded significant reductions in total and affective depression symptoms. Lithium responders (Li-Rs) showed improvement in circadian symptoms of depression, but non-responders did not. There was no difference between Li-Rs and nonresponders in affective, circadian, or total symptoms of mania. CONCLUSIONS: Exposure to lithium is associated with reduced circadian disruption. Lithium response at 12 weeks was selectively associated with the reduction of circadian depressive symptoms. We conclude that stabilization of circadian rhythms may be an important feature of lithium's therapeutic effects. CLINICAL TRIALS REGISTRY: NCT0127253.
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BACKGROUND: Life Goals is an evidence-based self-management intervention that assists individuals with bipolar disorder (BD) by aligning BD symptom coping strategies with their personal goals. The intervention can be availed via in-person and telephonic sessions, and it has been recently developed as an individualized, customizable mobile app. OBJECTIVE: We examined the feasibility, usability, and acceptability of the Life Goals self-management app among individuals diagnosed with BD who used the app for up to 6 months. METHODS: A total of 28 individuals with BD used the Life Goals app on their personal smartphone for 6 months. They completed key clinical outcome measurements of functioning, disability, and psychiatric symptoms at baseline, 3 months, and 6 months, in addition to a poststudy survey about usability and satisfaction. RESULTS: Participants used the app for a median of 25 times (IQR 13-65.75), and for a longer time during the first 3 months of the study. The modules on depression and anxiety were the most frequently used, accounting for 35% and 22% of total usage, respectively. Overall, the study participants found the app useful (15/25, 60%) and easy to use (18/25, 72%), and they reported that the screen displayed the material adequately (22/25, 88%). However, less than half of the participants found the app helpful in managing their health (10/25, 40%) or in making progress on their wellness goals (9/25, 36%). Clinical outcomes showed a trend for improvements in mental and physical health and mania-related well-being. CONCLUSIONS: The Life Goals app showed feasibility of use among individuals with BD. Higher user engagement was observed in the initial 3 months with users interested more frequently in the mood modules than other wellness modules. Participants reported acceptability with the ease of app use and satisfaction with the app user interface, but the app showed low success in encouraging self-management within this small sample. The Life Goals app is a mobile health technology that can provide individuals with serious mental illness with more flexible access to evidence-based treatments.
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OBJECTIVE: The increase in smartphone usage has enabled the possibility of more accessible ways to conduct neuropsychological evaluations. The objective of this study was to determine the feasibility of using smartphone typing dynamics with mood scores to supplement cognitive assessment through trail making tests. METHODS: Using a custom-built keyboard, naturalistic keypress dynamics were unobtrusively recorded in individuals with bipolar disorder (n = 11) and nonbipolar controls (n = 8) on an Android smartphone. Keypresses were matched to digital trail making tests part B (dTMT-B) administered daily in two periods and weekly mood assessments. Following comparison of dTMT-Bs to the pencil-and-paper equivalent, longitudinal mixed-effects models were used to analyze daily dTMT-B performance as a function of typing and mood. RESULTS: Comparison of the first dTMT-B to paper TMT-B showed adequate reliability (intraclass correlations = 0.74). In our model, we observed that participants who typed slower took longer to complete dTMT-B (b = 0.189, p < .001). This trend was also seen in individual fluctuations in typing speed and dTMT-B performance (b = 0.032, p = .004). Moreover, participants who were more depressed completed the dTMT-B slower than less depressed participants (b = 0.189, p < .001). A practice effect was observed for the dTMT-Bs. CONCLUSION: Typing speed in combination with depression scores has the potential to infer aspects of cognition (visual attention, processing speed, and task switching) in people's natural environment to complement formal in-person neuropsychological assessments that commonly include the trail making test.
Subject(s)
Executive Function , Smartphone , Cognition , Humans , Neuropsychological Tests , Reproducibility of Results , Trail Making TestABSTRACT
Numerous publications have described the behaviors employed by professional jockeys on a daily basis to achieve and maintain a minimum racing weight. This narrative review provides an update of recent publications that report on the impact of such practices. Although rapid weight-loss techniques such as calorie restriction and dehydration are commonly thought to be deleterious to jockeys, little evidence exists of enduring health consequences. There is evidence to suggest that jockey training behaviors and dietary choices are not aligned with optimum preparation for the physiological demands of the sport. Further research is necessary to better measure the health impact of jockey weight-making behaviors; such data might guide reforms of athlete behavior and regulatory practices within the global sport of horse racing.
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BACKGROUND: Individuals with bipolar I disorder (BD-I) experience both poor sleep and neuropsychological dysfunction relative to non-psychiatric populations, which limits functional recovery. Poor sleep adversely affects learning, memory, and executive functioning in healthy individuals; however, little is known about the role of poor sleep in neuropsychological functioning in BD-I. We tested whether sleep disturbance was greater in BD-I than healthy control participants (HC), and compared the effect of sleep quality on learning, memory, and executive functioning between BD-I and HC. METHODS: Participants with BD-I (N=250) and HC (N=206) completed the Pittsburgh Sleep Quality Index, neuropsychological testing, and clinician-administered mood measures as part of a naturalistic study of bipolar disorder. We examined effects of both diagnosis and sleep quality on neuropsychological functioning. RESULTS: Relative to HC, BD-I showed poorer sleep quality and neuropsychological functioning in verbal learning, verbal and visual memory, processing speed, psychomotor speed, inhibitory control, and selective attention (7/9 domains). Poor sleep quality was associated with poorer verbal learning, verbal fluency, processing speed, and interference control (4/9). Effects of poor sleep on neuropsychological functioning did not differ between BD-I and HC. LIMITATIONS: The assessment of sleep quality using a self-report measure and the effects of medications/sleeping aids (given the naturalistic study design) should be considered when interpreting results. CONCLUSIONS: Those with BD-I experiencing poor sleep may also be more vulnerable to verbal learning and executive functioning impairments. The findings of poor sleep in relation to poorer neuropsychological functioning have implications for assessment and treatment of sleep disturbance in BD-I.
Subject(s)
Bipolar Disorder , Cognition Disorders , Bipolar Disorder/complications , Executive Function , Humans , Neuropsychological Tests , SleepABSTRACT
BACKGROUND: Lithium is regarded as a first-line treatment for bipolar disorder (BD), but partial response and non-response commonly occurs. There exists a need to identify lithium non-responders prior to initiating treatment. The Pharmacogenomics of Bipolar Disorder (PGBD) Study was designed to identify predictors of lithium response. METHODS: The PGBD Study was an eleven site prospective trial of lithium treatment in bipolar I disorder. Subjects were stabilized on lithium monotherapy over 4 months and gradually discontinued from all other psychotropic medications. After ensuring a sustained clinical remission (defined by a score of ≤3 on the CGI for 4 weeks) had been achieved, subjects were followed for up to 2 years to monitor clinical response. Cox proportional hazard models were used to examine the relationship between clinical measures and time until failure to remit or relapse. RESULTS: A total of 345 individuals were enrolled into the study and included in the analysis. Of these, 101 subjects failed to remit or relapsed, 88 achieved remission and continued to study completion, and 156 were terminated from the study for other reasons. Significant clinical predictors of treatment failure (p < 0.05) included baseline anxiety symptoms, functional impairments, negative life events and lifetime clinical features such as a history of migraine, suicidal ideation/attempts, and mixed episodes, as well as a chronic course of illness. CONCLUSIONS: In this PGBD Study of lithium response, several clinical features were found to be associated with failure to respond to lithium. Future validation is needed to confirm these clinical predictors of treatment failure and their use clinically to distinguish who will do well on lithium before starting pharmacotherapy.
Subject(s)
Bipolar Disorder , Bipolar Disorder/diagnosis , Bipolar Disorder/drug therapy , Bipolar Disorder/genetics , Humans , Lithium/therapeutic use , Lithium Compounds/therapeutic use , Pharmacogenetics , Prospective Studies , Treatment OutcomeABSTRACT
BACKGROUND: Individuals with bipolar disorder (BD) show different personality profiles compared to non-psychiatric populations, but little is known about the temporal stability of personality traits over time, and if changes in mood state drive changes in personality. METHODS: Participants were 533 BD and 185 healthy controls (HC) who completed the NEO-Personality Inventory-Revised (NEO-PI-R) and clinician-administered measures of mood at baseline. One-hundred-eighty BD and 79 HC completed the measures at 5-year follow-up and 60 BD and 16 HC completed the measures at 10-year follow-up. The above measures and demographic information, but not other clinical status indicators the BD illness, were used in analyses. RESULTS: The BD group has higher Neuroticism (N)/N facets and lower Extraversion (E)/E facets and Consciousness (C)/C facets compared to HC. Significant mean-level changes existed within groups but were small in magnitude, and groups showed similar moderate-to-high rank-order stability. Change in (N)/N facets shows an association with change in depression, but changes in all other NEO-PI-R scores are not associated with changes in mood. Personality traits are clinically stable in part of our bipolar sample using clinically relevant interpretation of changes in T scores; however, some BD subjects did show more reliable changes in personality traits than the healthy controls. LIMITATIONS: Reliance on self-report measurement and not all our participants completed the 5- and 10-year follow-up personality assessment who were eligible to do so. CONCLUSIONS: Mean-level and rank-order personality scores show only modest changes, so most personality changes over time are not systematic. Observed changes in personality traits are not explained by changes in mood with the exception of Neuroticism, suggesting other factors influence changes in personality.
Subject(s)
Bipolar Disorder , Affect , Extraversion, Psychological , Humans , Personality , Personality InventoryABSTRACT
Background: Research by our group and others have demonstrated the feasibility of using mobile phone derived metadata to model mood and cognition. Given the effects of age and mood on cognitive performance, it was hypothesized that using such data a model could be built to predict chronological age and that differences between predicted age and actual age could be a marker of pathology. Methods: These data were collected via the ongoing BiAffect study. Participants complete the Mood Disorders Questionnaire (MDQ), a screening questionnaire for bipolar disorder, and self-reported their birth year. Data were split into training and validation sets. Features derived from the smartphone kinematics were used to train random forest regression models to predict age. Prediction errors were compared between participants screening positive and negative on the MDQ. Results: Three hundred forty-four participants had analyzable data of which 227 had positive screens for bipolar disorder and 117 had negative screens. The absolute prediction error tended to be lower for participants with positive screens (median 4.50 years) than those with negative screens (median 7.92 years) (W = 508, p = 0.0049). The raw prediction error tended to be lower for participants with negative screens (median = -5.95 years) than those with positive screens (median = 0.55 years) (W = 1,037, p= 0.037). Conclusions: The tendency to underestimate the chronological age of participants screening negative for bipolar disorder compared to those screening positive is consistent with the finding that bipolar disorder may be associated with brain changes that could reflect pathological aging. This interesting result could also reflect that those who screen negative for bipolar disorder and who engaged in the study were more likely to have higher premorbid functioning. This work demonstrates that age-related changes may be detected via a passive smartphone kinematics based digital biomarker.
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OBJECTIVES: Our goal was to characterise jockey injuries at Maryland racetracks during thoroughbred racing activities over 4 years using medical records maintained by the sports medicine team. METHODS: Injury data were prospectively gathered by sports medicine physicians who were onsite for all thoroughbred racing activities in Maryland from 12 September 2015 to 5 May 2019 to evaluate and treat any injury to the jockeys. Descriptive statistics (frequencies, rates with corresponding 95% CIs and proportions) of injury types, body parts, mechanisms, severity and location on track were calculated. RESULTS: Over nearly 4 years of racing and 45 000 mounts, there were 204 injuries involving 184 incidents and 131 falls during those races. The vast majority of injuries (80%) was related to soft tissue, while 4% were concussions. Most injuries involved the lower extremity (31%) or upper extremity (26%) and typically resulted from a fall from the horse. Among all incidents, 79.3% (n=146) resulted in an injury, while 76.3% (n=100) of falls resulted in an injury. We identified a significant proportion of injuries (41%) in and around the starting gate. Over a quarter of incidents resulting in injury required further medical care in hospital or other medical facility, while surgery was required in 2.5% of injuries. CONCLUSION: Access to a consistent group of sports medicine providers facilitated jockey injury reporting and tracking. The majority of jockey injuries is related to soft tissue and results from falls, while the starting gate area is associated with the greatest proportion of injuries.