I am a theoretical psychologist who specialises in evolutionary models of the human brain and depression, including mood disorders. More broadly, I have an interest in youth mental health, and identifying prevention, early intervention and treatment approaches that optimise outcomes for young people experiencing mental ill-health.
Australian & New Zealand Journal of Psychiatry
Objective: Depression and suicidal ideation are closely intertwined. Yet, among young people with... more Objective: Depression and suicidal ideation are closely intertwined. Yet, among young people with depression, the specific factors that contribute to changes in suicidal ideation over time are uncertain. Factors other than depressive symptom severity, such as comorbid psychopathology and personality traits, might be important contributors. Our aim was to identify contributors to fluctuations in suicidal ideation severity over a 12-week period in young people with major depressive disorder receiving cognitive behavioural therapy. Methods: Data were drawn from two 12-week randomised, placebo-controlled treatment trials. Participants ( N = 283) were 15–25 years old, with moderate to severe major depressive disorder. The primary outcome measure was the Suicidal Ideation Questionnaire, administered at baseline and weeks 4, 8 and 12. A series of linear mixed models was conducted to examine the relationship between Suicidal Ideation Questionnaire score and demographic characteristics, como...
Evaluating suicidal ideation in young people seeking mental health treatment is an important comp... more Evaluating suicidal ideation in young people seeking mental health treatment is an important component of clinical assessment and treatment planning. To reduce the burden of youth suicide, we need to improve our understanding of suicidal ideation, its underlying constructs, and how ideation translates into suicidal behaviour. Using exploratory factor analysis, we investigated the dimensionality of the Suicidal Ideation Questionnaire (SIQ) among 273 participants aged 15–25 with Major Depressive Disorder. Area under the receiver operating characteristic curve (AUROC) analysis was used to explore associations between latent factors and actual suicidal behaviour. Findings suggested that the SIQ assesses multiple factors underlying suicidal ideation. AUROC analyses demonstrated that latent factors relating to both active and passive suicidal ideation predicted past-month suicidal behaviour and suicide attempt. These findings contribute to an improved understanding of the complexities of ...
Australian & New Zealand Journal of Psychiatry, 2022
Objective: Depression is one of the most prevalent and disabling mental health conditions among y... more Objective: Depression is one of the most prevalent and disabling mental health conditions among young people worldwide. The health and economic burdens associated with depressive illness are substantial. Suicide and depression are closely intertwined, yet a diagnosis of depression itself lacks predictive specificity for suicidal behaviour. To better inform suicide prevention and early intervention strategies for young people, improved identification of modifiable intervention targets is needed. The objective of this review was to identify clinical, psychosocial and biological correlates of suicidality in young people diagnosed with a broad range of unipolar and bipolar depressive disorders. Method: Systematic searches were conducted across MEDLINE, Embase and PsycINFO to identify studies of young people aged 15–25 years diagnosed with unipolar or bipolar depressive disorders. An assessment of suicidality was required for inclusion. Reporting followed the Preferred Reporting Items fo...
OBJECTIVE The objective of this review is to examine clinical, psychosocial, and biological facto... more OBJECTIVE The objective of this review is to examine clinical, psychosocial, and biological factors associated with suicidality in young people diagnosed with depression. This review will describe risk and protective factors, focusing on modifiable attributes, in order to inform suicide prevention and early intervention strategies. INTRODUCTION Suicide is the world's second leading cause of death among young people. Depression is closely associated with suicide; however, it lacks specificity as a predictor of suicidal behavior. There is a clear need to improve our understanding of both risk and protective factors associated with the full spectrum of suicidality in young people, across a range of depressive disorders. INCLUSION CRITERIA Studies that include young people 15 to 25 years of age with a diagnosis of depression made in accordance with a diagnostic classification standard will be considered. Diagnosis must be made using a structured clinical interview or be received through standard clinical practice. Analytical cross-sectional studies, prospective and retrospective cohort studies, and case-control studies will be included. Studies must include an assessment of suicidality made using standardized or non-standardized tools. A broad range of inpatient and outpatient settings will be considered. METHODS MEDLINE, Embase, and PsycINFO will be searched for studies published in English, with no date limitation. Two independent reviewers will conduct study screening, assess methodological quality, and extract data using standardized tools. If there is sufficient homogeneity across studies, meta-analyses using a random-effects model will be conducted. If quantitative meta-analysis is not possible, a narrative synthesis will be undertaken. SYSTEMATIC REVIEW REGISTRATION NUMBER PROSPERO CRD42020151612.
BACKGROUND Suicidal ideation (SI) is a common feature of depression and is closely associated wit... more BACKGROUND Suicidal ideation (SI) is a common feature of depression and is closely associated with suicidal behaviour. Social support is implicated as an important determinant of suicide, but it is unclear how different social support dimensions influence SI in young people with depression. This study examines relationships between social support dimensions and SI in young people with major depressive disorder (MDD). METHODS 283 Australians aged 15-25, diagnosed with MDD, were recruited from two clinical trials conducted in youth-specific outpatient mental health services. The Multidimensional Scale of Perceived Social Support (MSPSS) was used to evaluate perceived support from Family, Friends, and a Significant Other. Suicidal ideation was assessed using the Suicidal Ideation Questionnaire (SIQ). Hierarchical regression was used to explore associations between social support and SI, controlling for demographics and depression severity. RESULTS A hierarchical regression model predicted 9% of the variability in SI, with depression severity being the most significant predictor. Family Support was inversely related to SI and uniquely contributed 2% of the variance; β = -0.15 (95% CI -0.27 - -0.02) p < .05. Demographics and support from Friends or a Significant Other were not significantly associated with SI. LIMITATIONS Findings are correlational; it cannot be determined that increasing family support would decrease SI severity. CONCLUSION Perceived Family Support was negatively associated with SI in young people with MDD. This suggests that family members might play important roles in suicide prevention efforts. More work is needed exploring ways to empower families to develop adaptive family functioning and support.
The free energy principle (FEP) is a formulation of the adaptive, belief-driven behaviour of self... more The free energy principle (FEP) is a formulation of the adaptive, belief-driven behaviour of self-organizing systems that gained prominence in the early 2000s as a unified model of the brain [...]
This paper proposes an integrative perspective on evolutionary, cultural and computational approa... more This paper proposes an integrative perspective on evolutionary, cultural and computational approaches to psychiatry. These three approaches attempt to frame mental disorders as multiscale entities and offer modes of explanations and modeling strategies that can inform clinical practice. Although each of these perspectives involves systemic thinking, each is limited in its ability to address the complex developmental trajectories and larger social systemic interactions that lead to mental disorders. Inspired by computational modeling in theoretical biology, this paper aims to integrate the modes of explanation offered by evolutionary, cultural and computational psychiatry in a multilevel systemic perspective. We apply the resulting Evolutionary, Cultural and Computational (ECC) model to Major Depressive Disorder (MDD) to illustrate how this integrative approach can guide research and practice in psychiatry.
Psychology is a theoretically heterogeneous discipline seeking a single, cohesive framework to un... more Psychology is a theoretically heterogeneous discipline seeking a single, cohesive framework to unite the subdisciplines. To address this issue, I propose a hierarchical metatheory of psychological science that synthesizes neo-Darwinian selectionist thinking and dynamic systems theory by organizing evolutionary psychology, evolutionary developmental biology, developmental psychobiology, and the subdisciplines of psychology around four specific, interrelated levels of analysis: functional explanations for evolved, species-typical characteristics; explanations for between-groups differences arising from phylogenetic mechanisms; explanations for individual differences resulting from ontogenetic processes; and mechanistic explanations for real-time phenomena, respectively. Informational exchange between these levels advances their integration and facilitates important innovations, and the nonsubstantive metatheories of general selection and self-organization interpenetrate all four level...
This study aimed to determine the prevalence of high-risk sexual behaviours, sequelae and associa... more This study aimed to determine the prevalence of high-risk sexual behaviours, sequelae and associated factors in young people attending a youth mental health service. The study design was a cross-sectional survey of 103 young people aged between 15-25 years carried out across four specialist mental health clinics. A questionnaire on the sexual health of secondary level students was adapted for this study. Mental health symptomatology was assessed through the Brief Psychiatric Rating Scale (BPRS). The mean age was 20.9 (SD ±2.8) years, with 50.5% being female, 41.7% male and 7.7% transgender. A total of 52.4% (N = 54) attended the psychosis [EPPIC] clinic; 15.6% (N = 16) attended the ultra-high risk for psychosis [PACE] clinic; 19.4% (N = 20) attended the personality disorders [HYPE] clinic; and 12.6% (N = 13) attended the mood clinic [YMC]. The mean BPRS score was 47.7 (SD ±12.2). A total of 77.7% of young people had previously been sexually active and of these, 37.5% did not use con...
This paper addresses the challenges faced by multiscale formulations of the variational (free ene... more This paper addresses the challenges faced by multiscale formulations of the variational (free energy) approach to dynamics that obtain for large-scale ensembles. We review a framework for modelling complex adaptive control systems for multiscale free energy bounding organism-niche dynamics, thereby integrating the modelling strategies and heuristics of variational neuroethology with a broader perspective on the ecological nestedness of biotic systems. We extend the multiscale variational formulation beyond the action-perception loops of individual organisms by appealing to the variational approach to niche construction to explain the dynamics of coupled systems constituted by organisms and their ecological niche. We suggest that the statistical robustness of living systems is inherited, in part, from their eco-niches, as niches help coordinate dynamical patterns across larger spatiotemporal scales. We call this approach variational ecology. We argue that, when applied to cultural an...
Australian & New Zealand Journal of Psychiatry
Objective: Depression and suicidal ideation are closely intertwined. Yet, among young people with... more Objective: Depression and suicidal ideation are closely intertwined. Yet, among young people with depression, the specific factors that contribute to changes in suicidal ideation over time are uncertain. Factors other than depressive symptom severity, such as comorbid psychopathology and personality traits, might be important contributors. Our aim was to identify contributors to fluctuations in suicidal ideation severity over a 12-week period in young people with major depressive disorder receiving cognitive behavioural therapy. Methods: Data were drawn from two 12-week randomised, placebo-controlled treatment trials. Participants ( N = 283) were 15–25 years old, with moderate to severe major depressive disorder. The primary outcome measure was the Suicidal Ideation Questionnaire, administered at baseline and weeks 4, 8 and 12. A series of linear mixed models was conducted to examine the relationship between Suicidal Ideation Questionnaire score and demographic characteristics, como...
Evaluating suicidal ideation in young people seeking mental health treatment is an important comp... more Evaluating suicidal ideation in young people seeking mental health treatment is an important component of clinical assessment and treatment planning. To reduce the burden of youth suicide, we need to improve our understanding of suicidal ideation, its underlying constructs, and how ideation translates into suicidal behaviour. Using exploratory factor analysis, we investigated the dimensionality of the Suicidal Ideation Questionnaire (SIQ) among 273 participants aged 15–25 with Major Depressive Disorder. Area under the receiver operating characteristic curve (AUROC) analysis was used to explore associations between latent factors and actual suicidal behaviour. Findings suggested that the SIQ assesses multiple factors underlying suicidal ideation. AUROC analyses demonstrated that latent factors relating to both active and passive suicidal ideation predicted past-month suicidal behaviour and suicide attempt. These findings contribute to an improved understanding of the complexities of ...
Australian & New Zealand Journal of Psychiatry, 2022
Objective: Depression is one of the most prevalent and disabling mental health conditions among y... more Objective: Depression is one of the most prevalent and disabling mental health conditions among young people worldwide. The health and economic burdens associated with depressive illness are substantial. Suicide and depression are closely intertwined, yet a diagnosis of depression itself lacks predictive specificity for suicidal behaviour. To better inform suicide prevention and early intervention strategies for young people, improved identification of modifiable intervention targets is needed. The objective of this review was to identify clinical, psychosocial and biological correlates of suicidality in young people diagnosed with a broad range of unipolar and bipolar depressive disorders. Method: Systematic searches were conducted across MEDLINE, Embase and PsycINFO to identify studies of young people aged 15–25 years diagnosed with unipolar or bipolar depressive disorders. An assessment of suicidality was required for inclusion. Reporting followed the Preferred Reporting Items fo...
OBJECTIVE The objective of this review is to examine clinical, psychosocial, and biological facto... more OBJECTIVE The objective of this review is to examine clinical, psychosocial, and biological factors associated with suicidality in young people diagnosed with depression. This review will describe risk and protective factors, focusing on modifiable attributes, in order to inform suicide prevention and early intervention strategies. INTRODUCTION Suicide is the world's second leading cause of death among young people. Depression is closely associated with suicide; however, it lacks specificity as a predictor of suicidal behavior. There is a clear need to improve our understanding of both risk and protective factors associated with the full spectrum of suicidality in young people, across a range of depressive disorders. INCLUSION CRITERIA Studies that include young people 15 to 25 years of age with a diagnosis of depression made in accordance with a diagnostic classification standard will be considered. Diagnosis must be made using a structured clinical interview or be received through standard clinical practice. Analytical cross-sectional studies, prospective and retrospective cohort studies, and case-control studies will be included. Studies must include an assessment of suicidality made using standardized or non-standardized tools. A broad range of inpatient and outpatient settings will be considered. METHODS MEDLINE, Embase, and PsycINFO will be searched for studies published in English, with no date limitation. Two independent reviewers will conduct study screening, assess methodological quality, and extract data using standardized tools. If there is sufficient homogeneity across studies, meta-analyses using a random-effects model will be conducted. If quantitative meta-analysis is not possible, a narrative synthesis will be undertaken. SYSTEMATIC REVIEW REGISTRATION NUMBER PROSPERO CRD42020151612.
BACKGROUND Suicidal ideation (SI) is a common feature of depression and is closely associated wit... more BACKGROUND Suicidal ideation (SI) is a common feature of depression and is closely associated with suicidal behaviour. Social support is implicated as an important determinant of suicide, but it is unclear how different social support dimensions influence SI in young people with depression. This study examines relationships between social support dimensions and SI in young people with major depressive disorder (MDD). METHODS 283 Australians aged 15-25, diagnosed with MDD, were recruited from two clinical trials conducted in youth-specific outpatient mental health services. The Multidimensional Scale of Perceived Social Support (MSPSS) was used to evaluate perceived support from Family, Friends, and a Significant Other. Suicidal ideation was assessed using the Suicidal Ideation Questionnaire (SIQ). Hierarchical regression was used to explore associations between social support and SI, controlling for demographics and depression severity. RESULTS A hierarchical regression model predicted 9% of the variability in SI, with depression severity being the most significant predictor. Family Support was inversely related to SI and uniquely contributed 2% of the variance; β = -0.15 (95% CI -0.27 - -0.02) p < .05. Demographics and support from Friends or a Significant Other were not significantly associated with SI. LIMITATIONS Findings are correlational; it cannot be determined that increasing family support would decrease SI severity. CONCLUSION Perceived Family Support was negatively associated with SI in young people with MDD. This suggests that family members might play important roles in suicide prevention efforts. More work is needed exploring ways to empower families to develop adaptive family functioning and support.
The free energy principle (FEP) is a formulation of the adaptive, belief-driven behaviour of self... more The free energy principle (FEP) is a formulation of the adaptive, belief-driven behaviour of self-organizing systems that gained prominence in the early 2000s as a unified model of the brain [...]
This paper proposes an integrative perspective on evolutionary, cultural and computational approa... more This paper proposes an integrative perspective on evolutionary, cultural and computational approaches to psychiatry. These three approaches attempt to frame mental disorders as multiscale entities and offer modes of explanations and modeling strategies that can inform clinical practice. Although each of these perspectives involves systemic thinking, each is limited in its ability to address the complex developmental trajectories and larger social systemic interactions that lead to mental disorders. Inspired by computational modeling in theoretical biology, this paper aims to integrate the modes of explanation offered by evolutionary, cultural and computational psychiatry in a multilevel systemic perspective. We apply the resulting Evolutionary, Cultural and Computational (ECC) model to Major Depressive Disorder (MDD) to illustrate how this integrative approach can guide research and practice in psychiatry.
Psychology is a theoretically heterogeneous discipline seeking a single, cohesive framework to un... more Psychology is a theoretically heterogeneous discipline seeking a single, cohesive framework to unite the subdisciplines. To address this issue, I propose a hierarchical metatheory of psychological science that synthesizes neo-Darwinian selectionist thinking and dynamic systems theory by organizing evolutionary psychology, evolutionary developmental biology, developmental psychobiology, and the subdisciplines of psychology around four specific, interrelated levels of analysis: functional explanations for evolved, species-typical characteristics; explanations for between-groups differences arising from phylogenetic mechanisms; explanations for individual differences resulting from ontogenetic processes; and mechanistic explanations for real-time phenomena, respectively. Informational exchange between these levels advances their integration and facilitates important innovations, and the nonsubstantive metatheories of general selection and self-organization interpenetrate all four level...
This study aimed to determine the prevalence of high-risk sexual behaviours, sequelae and associa... more This study aimed to determine the prevalence of high-risk sexual behaviours, sequelae and associated factors in young people attending a youth mental health service. The study design was a cross-sectional survey of 103 young people aged between 15-25 years carried out across four specialist mental health clinics. A questionnaire on the sexual health of secondary level students was adapted for this study. Mental health symptomatology was assessed through the Brief Psychiatric Rating Scale (BPRS). The mean age was 20.9 (SD ±2.8) years, with 50.5% being female, 41.7% male and 7.7% transgender. A total of 52.4% (N = 54) attended the psychosis [EPPIC] clinic; 15.6% (N = 16) attended the ultra-high risk for psychosis [PACE] clinic; 19.4% (N = 20) attended the personality disorders [HYPE] clinic; and 12.6% (N = 13) attended the mood clinic [YMC]. The mean BPRS score was 47.7 (SD ±12.2). A total of 77.7% of young people had previously been sexually active and of these, 37.5% did not use con...
This paper addresses the challenges faced by multiscale formulations of the variational (free ene... more This paper addresses the challenges faced by multiscale formulations of the variational (free energy) approach to dynamics that obtain for large-scale ensembles. We review a framework for modelling complex adaptive control systems for multiscale free energy bounding organism-niche dynamics, thereby integrating the modelling strategies and heuristics of variational neuroethology with a broader perspective on the ecological nestedness of biotic systems. We extend the multiscale variational formulation beyond the action-perception loops of individual organisms by appealing to the variational approach to niche construction to explain the dynamics of coupled systems constituted by organisms and their ecological niche. We suggest that the statistical robustness of living systems is inherited, in part, from their eco-niches, as niches help coordinate dynamical patterns across larger spatiotemporal scales. We call this approach variational ecology. We argue that, when applied to cultural an...
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