Mental health progress requires causal diagnostic nosology and scalable causal discovery

Nine hundred and seventy million individuals across the globe are estimated to carry the burden of a mental disorder. Limited progress has been achieved in alleviating this burden over decades of effort, compared to progress achieved for many other medical disorders. Progress on outcome improvement for all medical disorders, including mental disorders, requires research capable of discovering causality at sufficient scale and speed, and a diagnostic nosology capable of encoding the causal knowledge that is discovered. Accordingly, the field's guiding paradigm limits progress by maintaining: (a) a diagnostic nosology (DSM-5) with a profound lack of causality; (b) a misalignment between mental health etiologic research and nosology; (c) an over-reliance on clinical trials beyond their capabilities; and (d) a limited adoption of newer methods capable of discovering the complex etiology of mental disorders. We detail feasible directions forward, to achieve greater levels of progress on improving outcomes for mental disorders, by: (a) the discovery of knowledge on the complex etiology of mental disorders with application of Causal Data Science methods; and (b) the encoding of the etiological knowledge that is discovered within a causal diagnostic system for mental disorders.

Computational causal discovery for post-traumatic stress in police officers

This article reports on a study aimed to elucidate the complex etiology of post-traumatic stress (PTS) in a longitudinal cohort of police officers, by applying rigorous computational causal discovery (CCD) methods with observational data. An existing observational data set was used, which comprised a sample of 207 police officers who were recruited upon entry to police academy training. Participants were evaluated on a comprehensive set of clinical, self-report, genetic, neuroendocrine and physiological measures at baseline during academy training and then were re-evaluated at 12 months after training was completed. A data-processing pipeline-the Protocol for Computational Causal Discovery in Psychiatry (PCCDP)-was applied to this data set to determine a causal model for PTS severity. A causal model of 146 variables and 345 bivariate relations was discovered. This model revealed 5 direct causes and 83 causal pathways (of four steps or less) to PTS at 12 months of police service. Direct causes included single-nucleotide polymorphisms (SNPs) for the Histidine Decarboxylase (HDC) and Mineralocorticoid Receptor (MR) genes, acoustic startle in the context of low perceived threat during training, peritraumatic distress to incident exposure during first year of service, and general symptom severity during training at 1 year of service. The application of CCD methods can determine variables and pathways related to the complex etiology of PTS in a cohort of police officers. This knowledge may inform new approaches to treatment and prevention of critical incident related PTS.

Editorial: In the Causal Labyrinth: Finding the Path From Early Trauma to Neurodevelopment

Exposure to traumatic events early in life has been associated with significant adverse neurodevelopmental consequences.^1,2 Ideally, protecting children from trauma would prevent these consequences. Unfortunately, once a child is exposed to early trauma, the only means of prevention requires implementing effective interventions toward the mechanisms known to have caused the consequences. Therefore, it is imperative to carefully define the true mechanistic pathways from which the neurodevelopmental consequences of early trauma result. The process of determining the correct pathway(s) is not a trivial matter, as is made clear from a valiant effort reported in this issue of the Journal titled, "Early Sexual Trauma Exposure and Neural Response Inhibition in Adolescence and Young Adults: Trajectories of Frontal Theta Oscillations During a Go/No-Go Task."³ This editorial reviews the effort to infer causal mechanism in this article, and introduces a literature that can improve the field's capacity to infer causes from observational data.

Brain entropy and human intelligence: A resting-state fMRI study

Human intelligence comprises comprehension of and reasoning about an infinitely variable external environment. A brain capable of large variability in neural configurations, or states, will more easily understand and predict variable external events. Entropy measures the variety of configurations possible within a system, and recently the concept of brain entropy has been defined as the number of neural states a given brain can access. This study investigates the relationship between human intelligence and brain entropy, to determine whether neural variability as reflected in neuroimaging signals carries information about intellectual ability. We hypothesize that intelligence will be positively associated with entropy in a sample of 892 healthy adults, using resting-state fMRI. Intelligence is measured with the Shipley Vocabulary and WASI Matrix Reasoning tests. Brain entropy was positively associated with intelligence. This relation was most strongly observed in the prefrontal cortex, inferior temporal lobes, and cerebellum. This relationship between high brain entropy and high intelligence indicates an essential role for entropy in brain functioning. It demonstrates that access to variable neural states predicts complex behavioral performance, and specifically shows that entropy derived from neuroimaging signals at rest carries information about intellectual capacity. Future work in this area may elucidate the links between brain entropy in both resting and active states and various forms of intelligence. This insight has the potential to provide predictive information about adaptive behavior and to delineate the subdivisions and nature of intelligence based on entropic patterns.

Machine learning methods to predict child posttraumatic stress: a proof of concept study

BACKGROUND

The care of traumatized children would benefit significantly from accurate predictive models for Posttraumatic Stress Disorder (PTSD), using information available around the time of trauma. Machine Learning (ML) computational methods have yielded strong results in recent applications across many diseases and data types, yet they have not been previously applied to childhood PTSD. Since these methods have not been applied to this complex and debilitating disorder, there is a great deal that remains to be learned about their application. The first step is to prove the concept: Can ML methods - as applied in other fields - produce predictive classification models for childhood PTSD? Additionally, we seek to determine if specific variables can be identified - from the aforementioned predictive classification models - with putative causal relations to PTSD.

METHODS

ML predictive classification methods - with causal discovery feature selection - were applied to a data set of 163 children hospitalized with an injury and PTSD was determined three months after hospital discharge. At the time of hospitalization, 105 risk factor variables were collected spanning a range of biopsychosocial domains.

RESULTS

Seven percent of subjects had a high level of PTSD symptoms. A predictive classification model was discovered with significant predictive accuracy. A predictive model constructed based on subsets of potentially causally relevant features achieves similar predictivity compared to the best predictive model constructed with all variables. Causal Discovery feature selection methods identified 58 variables of which 10 were identified as most stable.

CONCLUSIONS

In this first proof-of-concept application of ML methods to predict childhood Posttraumatic Stress we were able to determine both predictive classification models for childhood PTSD and identify several causal variables. This set of techniques has great potential for enhancing the methodological toolkit in the field and future studies should seek to replicate, refine, and extend the results produced in this study.

A Complex Systems Approach to Causal Discovery in Psychiatry

Conventional research methodologies and data analytic approaches in psychiatric research are unable to reliably infer causal relations without experimental designs, or to make inferences about the functional properties of the complex systems in which psychiatric disorders are embedded. This article describes a series of studies to validate a novel hybrid computational approach–the Complex Systems-Causal Network (CS-CN) method–designed to integrate causal discovery within a complex systems framework for psychiatric research. The CS-CN method was first applied to an existing dataset on psychopathology in 163 children hospitalized with injuries (validation study). Next, it was applied to a much larger dataset of traumatized children (replication study). Finally, the CS-CN method was applied in a controlled experiment using a ‘gold standard’ dataset for causal discovery and compared with other methods for accurately detecting causal variables (resimulation controlled experiment). The CS-CN method successfully detected a causal network of 111 variables and 167 bivariate relations in the initial validation study. This causal network had well-defined adaptive properties and a set of variables was found that disproportionally contributed to these properties. Modeling the removal of these variables resulted in significant loss of adaptive properties. The CS-CN method was successfully applied in the replication study and performed better than traditional statistical methods, and similarly to state-of-the-art causal discovery algorithms in the causal detection experiment. The CS-CN method was validated, replicated, and yielded both novel and previously validated findings related to risk factors and potential treatments of psychiatric disorders. The novel approach yields both fine-grain (micro) and high-level (macro) insights and thus represents a promising approach for complex systems-oriented research in psychiatry.

Trauma Systems Therapy in Residential Settings: Improving Emotion Regulation and the Social Environment of Traumatized Children and Youth in Congregate Care

Although abundant evidence exists indicating the prevalence of trauma exposure among youth in residential care, few models exist for creating trauma-informed milieu treatment. This article outlines the problem and describes the implementation of Trauma Systems Therapy (TST) in three residential centers. TST is unique in emphasizing youth emotions and behaviors as well as the role a distressed or threatening social environment may play in keeping a traumatized youth in a dysregulated state. This dual emphasis makes TST specifically appropriate to implementation in congregate care, focusing assessment and intervention strategies on both clinical treatment and the functioning of the therapeutic milieu itself. Data are reported on incidents of the use of physical restraint; numbers of disrupted foster care placements following discharge from residential treatment; and scores on psychometric measures of children's functioning and emotion regulation capacity. Knowledge gained through TST implementation in these three residential centers has important implications for developing a model of trauma-informed congregate care.

Innovations in Practice: Preliminary evidence for effective family engagement in treatment for child traumatic stress-trauma systems therapy approach to preventing dropout

BACKGROUND

  This study aimed to obtain preliminary evidence for the extent to which a novel intervention embedded within a systems-oriented treatment model [trauma systems therapy (TST)] engages and retains traumatized children and their families in treatment.

METHOD

  Twenty youth who had prominent symptoms of posttraumatic stress were randomly assigned to receive TST or care as usual (CAU).

RESULTS

  At the 3-month assessment, 90% of TST participants were still in treatment, whereas only 10% of CAU participants remained. Within-group analyses of TST participants demonstrated significant reductions in posttraumatic stress and aggression as well as a slight improvement in home safety.

CONCLUSIONS

  These preliminary findings point to the need to utilize effective engagement approaches to retain traumatized children and their families in treatment.

A randomized controlled trial of sertraline to prevent posttraumatic stress disorder in burned children

BACKGROUND

This study evaluated the potential benefits of a centrally acting selective serotonin reuptake inhibitor, sertraline, versus placebo for prevention of symptoms of posttraumatic stress disorder (PTSD) and depression in burned children. This is the first controlled investigation based on our review of the early use of a medication to prevent PTSD in children.

METHODS

Twenty-six children aged 6-20 were assessed in a 24-week double-blind placebo-controlled design. Each child received either flexibly dosed sertraline between 25-150 mg/day or placebo. At each reassessment, information was collected in compliance with the study medication, parental assessment of the child's symptomatology and functioning, and the child's self-report of symptomatology. The protocol was approved by the Human Studies Committees of Massachusetts General Hospital and Shriners Hospitals for Children.

RESULTS

The final sample was 17 subjects who received sertraline versus 9 placebo control subjects matched for age, severity of injury, and type of hospitalization. There was no significant difference in change from baseline with child-reported symptoms; however, the sertraline group demonstrated a greater decrease in parent-reported symptoms over 8 weeks (-4.1 vs. -0.5, p=0.005), over 12 weeks (-4.4 vs. -1.2, p=.008), and over 24 weeks (-4.0 vs. -0.2, p=0.017).

CONCLUSIONS

Sertraline was a safe drug, and it was somewhat more effective in preventing PTSD symptoms than placebo according to parent report but not child report. Based on this study, sertraline may prevent the emergence of PTSD symptoms in children.

Latent difference score approach to longitudinal trauma research

In this article, the authors introduce a latent difference score (LDS) approach to analyzing longitudinal data in trauma research. The LDS approach accounts for internal sources of change in an outcome variable, including the influence of prior status on subsequent levels of that variable and the tendency for individuals to experience natural change (e.g., a natural decrease in posttraumatic stress disorder [PTSD] symptoms over time). Under traditional model assumptions, the LDSs are maximally reliable and therefore less likely to introduce biases into model testing. The authors illustrate the method using a sample of children who experienced significant burns or other injuries to examine potential influences (i.e., age of child-adolescent at time of trauma and ongoing family strains) on PTSD symptom severity over time.

The long-term consequences of early childhood trauma: a case study and discussion

There is a great need to better understand the impact of traumatic events very early in life on the course of children's future development. This report focuses on the intriguing case of a girl who witnessed the murder of her mother by her father at the age of 19 months and seemed to have no recollection of this incident until the age of 11, when she began to exhibit severe symptoms of posttraumatic stress disorder (PTSD) in response to a traumatic reminder. The case presentation serves as the basis for a discussion regarding pertinent issues involved in early childhood trauma. This case and accompanying discussion were originally presented at the 19th Annual Meeting of the International Society for Traumatic Stress Studies and were transcribed and revised for use in this article. Specific topics include early childhood memory and trauma, learning and the appraisal of danger, and PTSD and traumatic grief in early childhood. Clinical and public health implications are also discussed. This case illustrates the dramatic impact that "preverbal" traumatic memories can have on children's later functioning and speaks to the importance of assisting very young children in the immediate aftermath of traumatic events.

Incidence of and Risk Factors for Acute Stress Disorder in Children with Injuries

BACKGROUND

To assess the incidence of and risk factors for Acute Stress Disorder (ASD) in children with injuries. Numerous studies have documented the increased incidence of PTSD in those initially diagnosed with ASD. PTSD symptoms cause tremendous morbidity and may persist for many years in some children.

METHODS

Children hospitalized with one or more injuries were interviewed and assessed with the following: Child Stress Disorders Checklist (CSDC), Family Strains Scale, Brief Symptom Inventory (BSI) and Facial Pain Scale.

RESULTS

Participants included sixty-five children (ages 7-18 years). The mechanisms of injury varied (e.g. MVC, penetrating). The mean injury severity score was 8.9 +/- 7. The mean length of hospital stay was 4.6 +/- 4.6 days. Altogether, 18 (27.7%) of participants met DSM IV criteria for ASD during their acute hospital stay. Risk factors such as level of family stress, caregiver stress, child's experience of pain, and child's age were predictive of acute stress symptoms.

CONCLUSION

We have identified four risk factors of ASD that have implications for the treatment, and possibly, preventative intervention for PTSD. Further investigation and greater understanding of risk factors for ASD in children with injuries may facilitate the design of acute interventions to prevent the long-term negative outcomes of traumatic events.

Pathways to PTSD, part I: Children with burns

OBJECTIVE

The goal of this study was to develop a model of risk factors for posttraumatic stress disorder (PTSD) in a group of acutely burned children.

METHOD

Seventy-two children between the ages of 7 and 17 who were admitted to the hospital for an acute burn were eligible for study. Members of families who consented completed the Child PTSD Reaction Index, the Multidimensional Anxiety Scale for Children, and other self-report measures of psychopathology and environmental stress both during the hospitalization and 3 months following the burn. A path analytic strategy was used to build a model of risk factors for PTSD.

RESULTS

Two pathways to PTSD were discerned: 1) from the size of the burn and level of pain following the burn to the child's level of acute separation anxiety, and then to PTSD, and 2) from the size of the burn to the child's level of acute dissociation following the burn, and then to PTSD. Together these pathways accounted for almost 60% of the variance in PTSD symptoms and constituted a model with excellent fit indices.

CONCLUSIONS

These findings support a model of complex etiology for childhood PTSD in which two independent pathways may be mediated by different biobehavioral systems.

Pathways to PTSD, part II: Sexually abused children

OBJECTIVE

The goal of this research was to develop and test a prospective model of posttraumatic stress symptoms in sexually abused children that includes pretrauma, trauma, and disclosure-related pathways.

METHOD

At time 1, several measures were used to assess pretrauma variables, trauma variables, and stress reactions upon disclosure for 156 sexually abused children ages 8 to 13 years. At the time 2 follow-up (7 to 36 months following the initial interview), the children were assessed for posttraumatic stress disorder (PTSD) symptoms.

RESULTS

A path analysis involving a series of hierarchically nested ordinary least squares multiple regression analyses indicated three direct paths to PTSD symptoms: avoidant coping, anxiety/arousal, and dissociation, all measured during or immediately after disclosure of sexual abuse. Additionally, age and gender predicted avoidant coping, while life stress and age at abuse onset predicted symptoms of anxiety/arousal. Taken together, these pathways accounted for approximately 57% of the variance in PTSD symptoms.

CONCLUSIONS

Symptoms measured at the time of disclosure constitute direct, independent pathways by which sexually abused children are likely to develop later PTSD symptoms. These findings speak to the importance of assessing children during the disclosure of abuse in order to identify those at greatest risk for later PTSD symptoms.

Testimonial psychotherapy for adolescent refugees: a case series

Adolescent refugees are a traumatized, vulnerable group of arrivals to America who lack experience with or interest in psychiatric care. Testimonial psychotherapy's unique focus on transcribing personal, traumatic events for the altruistic purpose of education and advocacy make it an acceptable interaction by which to bridge the cultural gap that prevents young refugees from seeking psychiatric care. The theoretical basis for testimony is discussed. Testimonial psychotherapy has been used with adult refugees, but not with adolescents. This article describes the testimonial process with three Sudanese adolescents (the so-called 'Lost Boys'), which appeared feasible and safe. An efficacy study is underway.

Review of child and adolescent refugee mental health

OBJECTIVE

To review stressful experiences and stress reactions among child and adolescent refugees, as well as interventions and ethical considerations in research and clinical work, within the framework of the chronological experiences of child refugees; namely, the phases of preflight, flight, and resettlement. Highlighted are special refugee populations such as unaccompanied minors, asylum seekers, and former child soldiers. Pertinent medical findings are summarized.

METHOD

The authors reviewed articles from 1990 to 2003 addressing the topics above. Literature was gathered from databases including PsycINFO, Medline, and SocioFile. Pertinent earlier papers and those from other disciplines cited in database-identified articles were also included.

RESULTS

Child and adolescent refugees suffer from significant conflict-related exposures. Reactions to stress may be mediated by coping strategies, belief systems, and social relations.

CONCLUSIONS

More research is needed on interventions, specifically on efficacy and cultural relevance. Interventions that have an impact on multiple ecological levels need further development and evaluation.

Posttraumatic stress responses in children with life-threatening illnesses

Posttraumatic stress symptoms have been reported in response to various serious medical illnesses in adults and children. Not surprisingly, posttraumatic stress is probably more common in response to acute, life-threatening, events that are related to the illness. Emerging data suggest that children often experience life-saving medical procedures as traumatic, which puts caretakers and medical personnel in the role of perpetrators for the children. Trauma symptoms are also reported as common and severe in caregivers. Both of these issues have been previously poorly understood and should be addressed in assessment and treatment. As with other traumatic events, developmental considerations, the nature and severity of the event itself, social supports, and premorbid exposure to negative life events are also important issues to consider in developing appropriate interventions. The importance of developing prevention and treatment for PTSD in medically ill children and adults includes increased morbidity and mortality (e.g., nonadherence to medications) and psychiatric sequelae and decreased quality of life. Obstacles to systematic study of a psychiatric intervention for this group include difficulties assessing multidrug regimens and cognitive treatment effects in this group. The relative stability of social supports and the potential use of preventive measures make this an attractive population for intervention. Clinicians and researchers are encouraged to work together to develop and use uniform screening and assessment methods that will help to identify cases and facilitate the multicenter trials that are vital to increasing knowledge in this patient population.

Self-destructive behavior in patients with dissociative disorders

Highrates of self-injury have been reported in patients with dissociative disorders, yet no prior study has directly compared these patients with other psychiatric patients. The present study assesses self-destructive behavior in a group of inpatients who have dissociative disorders compared to those who report few dissociative symptoms. These patients more frequently engage in self-destructive behaviors, use more methods of self-injury, and begin to injure themselves at an earlier age then patients who do not dissociate. Results have important implications for understanding the relationship between dissociation, childhood trauma, and self-injury and for assessment and treatment of patients with dissociative disorders.

Treatment of pain in acutely burned children

The child with burns suffers severe pain at the time of the burn and during subsequent treatment and rehabilitation. Pain has adverse physiological and emotional effects, and research suggests that pain management is an important factor in better outcomes. There is increasing understanding of the private experience of pain, and how children benefit from honest preparation for procedures. Developmentally appropriate and culturally sensitive pain assessment, pain relief, and reevaluation have improved, becoming essential in treatment. Pharmacological treatment is primary, strengthened by new concepts from neurobiology, clinical science, and the introduction of more effective drugs with fewer adverse side effects and less toxicity. Empirical evaluation of various hypnotic, cognitive, behavioral, and sensory treatment methods is advancing. Multidisciplinary assessment helps to integrate psychological and pharmacological pain-relieving interventions to reduce emotional and mental stress, and family stress as well. Optimal care encourages burn teams to integrate pain guidelines into protocols and critical pathways for improved care.

Somatization in patients with dissociative disorders

OBJECTIVE

This study attempted to determine the prevalence of somatic symptoms, somatization disorder, and medical interventions in patients with dissociative disorders.

METHOD

Fourteen psychiatric inpatients with a DSM-III dissociative disorder were matched for age and gender with a comparison group of inpatients who reported few dissociative symptoms. All subjects were interviewed in a blind manner with the Dissociative Disorders Interview Schedule (this semistructured interview schedule includes a section on somatization disorder), and their hospital charts were reviewed to determine somatic symptoms and medical histories.

RESULTS

Sixty-four percent of the patients with dissociative disorders met DSM-III criteria for somatization disorder and reported an average of 12.4 somatic symptoms. None of the comparison patients met DSM-III criteria for somatization disorder, and these patients reported an average of 3.1 somatic symptoms. These differences between the two groups were significant. Significant differences were also found in the number of medical hospitalizations and consultations between the two groups. A significant correlation was found between the degree of dissociation and degree of somatization in patients with dissociative disorders.

CONCLUSIONS

The authors conclude that somatization disorder is a frequent and serious comorbid disorder among patients with dissociative disorders.

Dissociative disorders in psychiatric inpatients

OBJECTIVE

This study attempted to determine 1) the prevalence of dissociative disorders in psychiatric inpatients, 2) the degree of reported childhood trauma in patients with dissociative disorders, and 3) the degree to which dissociative experiences are recognized in psychiatric patients.

METHOD

A total of 110 patients consecutively admitted to a state psychiatric hospital were given the Dissociative Experiences Scale. Patients who scored above 25 were matched for age and gender with a group of patients who scored below 5 on the scale. All patients in the two groups were then interviewed in a blind manner, and the Dissociative Disorders Interview Schedule, the Traumatic Antecedent Questionnaire, and the posttraumatic stress disorder (PTSD) module of the Structured Clinical Interview for DSM-III-R, Nonpatient Version, were administered. Chart reviews were also conducted on all patients.

RESULTS

Fifteen percent of the psychiatric patients scored above 25 on the Dissociative Experiences Scale; 100% of these patients met DSM-III criteria for a dissociative disorder. These patients had significantly higher rates of major depression, PTSD, substance abuse, and borderline personality than did the comparison patients, and they also reported significantly higher rates of childhood trauma. Chart review data revealed that dissociative symptoms were largely unrecognized.

CONCLUSIONS

A high proportion of psychiatric inpatients have significant dissociative pathology, and these symptoms are underrecognized by clinicians. The proper diagnosis of these patients has important implications for their clinical course.