Mohammad H. Afzali

A network approach to the comorbidity between posttraumatic stress disorder and major depressive disorder: The role of overlapping symptoms

BACKGROUNDnThe role of symptom overlap between major depressive disorder and posttraumatic stress disorder in comorbidity between two disorders is unclear. The current study applied network analysis to map the structure of symptom associations between these disorders.nnnMETHODSnData comes from a sample of 909 Australian adults with a lifetime history of trauma and depressive symptoms. Data analysis consisted of the construction of two comorbidity networks of PTSD/MDD with and without overlapping symptoms, identification of the bridging symptoms, and computation of the centrality measures.nnnRESULTSnThe prominent bridging role of four overlapping symptoms (i.e., sleep problems, irritability, concentration problems, and loss of interest) and five non-overlapping symptoms (i.e., feeling sad, feelings of guilt, psychomotor retardation, foreshortened future, and experiencing flashbacks) is highlighted.nnnLIMITATIONSnThe current study uses DSM-IV criteria for PTSD and does not take into consideration significant changes made to PTSD criteria in DSM-5. Moreover, due to cross-sectional nature of the data, network estimates do not provide information on whether a symptom actively triggers other symptoms or whether a symptom mostly is triggered by other symptoms.nnnCONCLUSIONnThe results support the role of dysphoria-related symptoms in PTSD/MDD comorbidity. Moreover, Identification of central symptoms and bridge symptoms will provide useful targets for interventions that seek to intervene early in the development of comorbidity.

Network approach to the symptom-level association between alcohol use disorder and posttraumatic stress disorder

PurposeThe high prevalence of alcohol use disorder among individuals with a history of trauma and posttraumatic stress disorder is well documented. The current study applied network analysis to map the structure of symptom associations between these disorders.MethodsData come from a community sample of 449 Australian adults with a history of trauma and alcohol consumption during the last 12xa0months. Data analysis consisted of the construction of the comorbidity network of PTSD/AUD symptoms, identification of the bridging symptoms, computation of the centrality measures, and evaluation of the robustness of the results.ResultsResults highlighted two main symptom clusters, corresponding to two disorders, and that only nine edges connected the two clusters. Bridging symptoms connecting the two clusters were: alcohol use in dangerous situations, physical or mental health problems as a result of alcohol use, loss of interest or reduced social activities, and reckless/self-destructive behaviour.ConclusionsIdentification of both central symptoms, because of their key role in the constellation and strong associations with majority of symptoms, and bridge symptoms, because of their mediating role between two disorders, has some implications in terms of self-medication and risk-taking/self-regulation theories of comorbidity and provides a number of clinical implications, which warrants further exploration within clinical samples.

The relationship between social support networks and depression in the 2007 National Survey of Mental Health and Well-being

PurposeSocial isolation and low levels of social support are associated with depression. The purpose of the current study was to investigate the relationship between depression and social connectivity factors (frequency of contact and quality of social connections) in the 2007 Australian National Survey of Mental Health and Well-being.MethodsA national survey of 8841 participants aged 16–85xa0years was conducted. Logistic regression was used to investigate the relationship between social connectivity factors and 12-month prevalence of Major Depressive Disorder in the whole sample, as well as across three age groups: younger adults (16–34xa0years), middle-aged adults (35–54xa0years), and older adults (55+ years). Respondents indicated how often they were in contact with family members and friends (frequency of contact), and how many family and friends they could rely on and confide in (quality of support), and were assessed for Major Depressive Disorder using the World Mental Health Composite International Diagnostics Interview.ResultsOverall, higher social connection quality was more closely and consistently associated with lower odds of the past year depression, relative to frequency of social interaction. The exception to this was for the older group in which fewer than a single friendship interaction each month was associated with a two-fold increased likelihood of the past year depression (OR 2.19, 95% CI 1.14–4.25). Friendship networks were important throughout life, although in middle adulthood, family support was also critically important—those who did not have any family support had more than a three-fold increased odds of the past year depression (OR 3.47, 95% CI 2.07–5.85).ConclusionsHigh-quality social connection with friends and family members is associated with reduced likelihood of the past year depression. Intervention studies that target the quality of social support for depression, particularly support from friends, are warranted.

Cannabis use and psychotic-like experiences trajectories during early adolescence: the coevolution and potential mediators

BACKGROUNDnThe authors sought to model the different trajectories of psychotic-like experiences (PLE) during adolescence and to examine whether the longitudinal relationship between cannabis use and PLE is mediated by changes in cognitive development and/or change in anxiety or depression symptoms.nnnMETHODSnA total of 2,566 youths were assessed every year for 4-years (from 13- to 16-years of age) on clinical, substance use and cognitive development outcomes. Latent class growth models identified three trajectories of PLE: low decreasing (83.9%), high decreasing (7.9%), and moderate increasing class (8.2%). We conducted logistic regressions to investigate whether baseline levels and growth in cannabis use were associated with PLE trajectory membership. Then, we examined the effects of potential mediators (growth in cognition and anxiety/depression) on the relationship between growth in cannabis use and PLE trajectory.nnnRESULTSnA steeper growth in cannabis use from 13- to 16-years was associated with a higher likelihood of being assigned to the moderate increasing trajectory of PLE [odds ratio, 2.59; 95% confidence interval (CI), 1.11-6.03], when controlling for cumulative cigarette use. Growth in depression symptoms, not anxiety or change in cognitive functioning, mediated the relationship between growth in cannabis use and the PLE moderate increasing group (indirect effect: 0.07; 95% CI, 0.03-0.11).nnnCONCLUSIONSnDepression symptoms partially mediated the longitudinal link between cannabis use and PLE in adolescents, suggesting that there may be a preventative effect to be gained from targeting depression symptoms, in addition to attempting to prevent cannabis use in youth presenting increasing psychotic experiences.

Trauma characteristics, post-traumatic symptoms, psychiatric disorders and suicidal behaviours: Results from the 2007 Australian National Survey of Mental Health and Wellbeing.

Objective: The current study examined whether trauma characteristics such as the type and number of traumatic events were associated with three suicidal behaviours (i.e. ideation, plan and attempt) after adjusting for sociodemographic factors, post-traumatic symptoms and history of psychiatric disorders. Method: Data came from the 2007 Australian National Survey of Mental Health and Wellbeing (Nu2009=u20098841). Respondents were asked about exposure to 28 traumatic events that occurred during their lifetime. Suicidal behaviours were measured using three statements about whether the person ever seriously thought about or planned or attempted suicide. Results: Sexual violence and exposure to multiple traumatic events were particularly associated with suicidal behaviours. The presence of the emotional numbing symptom cluster and co-occurrence of three psychiatric disorders (major depressive disorder, alcohol use disorder and substance use disorder) also increased the odds of suicidal behaviours. Analysis of age of onset revealed that the mean age of traumatic exposure was earlier than the age at which suicidal behaviours emerged. Conclusions: The current study is the first to demonstrate that sexual violence and exposure to multiple traumatic events are associated with suicidal behaviours in a representative sample of Australian adults. The results underline the potential benefits of thorough assessment of trauma history, post-traumatic symptoms and history of psychiatric disorders and their additive contribution in suicide risk among trauma victims. These findings can be used by clinicians and researchers for early intervention programmes.

The Structure of Psychopathology in Early Adolescence: Study of a Canadian Sample: La structure de la psychopathologie au début de l’adolescence: étude d’un échantillon canadien

Objective: The current study investigates the correlational structure of psychopathology in a large sample of Canadian adolescents and highlights the association between the psychopathological dimensions and gender. Method: Data came from 3826 Canadian adolescents aged 12.8 ± 0.4 y. Five alternative dimensional models were tested using confirmatory factor analysis, and the association between gender, language, and the mean level of psychopathological dimensions was examined using a multiple-indicators multiple-causes model. Results: A bifactor model with 1 general psychopathology factor and 3 specific dimensions (internalizing, externalizing, thought disorder) provided the best fit to the data. Results indicated metric invariance of the bifactor structure with respect to language. Females reported higher mean levels of internalizing, and males reported higher mean levels of externalizing. No significant sex differences emerged in liability to thought disorder or general psychopathology. The presence of a general psychopathology factor increased the association between gender and specific dimensions. Conclusions: The current study is the first to highlight the bifactor structure including a specific thought disorder factor in a Canadian sample of adolescents. The findings further highlight the importance of transdiagnostic approaches to prevention and intervention among young adolescents.

Association of Cannabis Use With Adolescent Psychotic Symptoms

This cohort study investigates year-to-year associations between cannabis use and psychosis over 4 years in youth aged 13 to 16 years.

Effect of depressive symptoms on the evolution of neuropsychological functions over the course of adolescence

INTRODUCTIONnComprehensive understanding of the association between depression and neuropsychological functioning over the course of adolescence requires developmentally sensitive assessment through longitudinal data. The aim of current study is to examine the concurrent and subsequent effects of depressive symptoms on the initial level and evolution of four neuropsychological functioning domains (i.e., spatial working memory, delayed recall memory, perceptual reasoning, and inhibitory control).nnnMETHODnDepressive symptoms and neuropsychological functioning were assessed over the course of four years in a sample of 3826 Canadian adolescents. A series of multilevel models estimated the between-person, within-person, and lagged within-person effects of depressive symptoms on each domain of neuropsychological functioning.nnnRESULTSnFindings suggest that current year and past year depressive symptoms were associated with poorer performance in delayed recall memory and perceptual reasoning tasks. Likewise, past year depressive symptoms were associated with poorer spatial working memory performance. These detrimental effects were stronger in early adolescence.nnnLIMITATIONSnThe current study examined the presence of sub-clinical depressive symptoms but not clinical depression. Moreover, although depressive symptoms and neuropsychological functions were assessed using widely used, valid, and reliable computer-based instruments, the results may not match the accuracy of clinician-based assessments.nnnCONCLUSIONSnOur results underline the necessity of early intervention for young adolescents to decrease the harms associated with depression. The effect of early-onset depression on the underlying neural substrates of neuropsychological functioning merits further investigation.

Poor response inhibition and peer victimization: A neurocognitive ecophenotype of risk for adolescent interpersonal aggression.

Relationship between poor inhibitory control and adolescent interpersonal difficulties is well-documented. However, the way in which an emotionally neutral cognitive process (i.e., response inhibition) can lead to interpersonal difficulties is less clear. The current study is based on multimodal longitudinal data from 3,826 adolescents followed over a 4-year period. The main aim of this study was to examine an ecophenotype conceptualization of the association between response inhibition and bullying perpetration through increasing vulnerability of peer victimization and a negative attributional style toward self and others. To test for potential mediations, we first tested the independent effects of the main predictor (response inhibition) and proposed mediators (victimization, hostile automatic thoughts, and self esteem). Multilevel models highlighted independent effects of response inhibition, hostility-related automatic thoughts, and self-esteem in susceptibility to peer victimization and bullying perpetration, both in terms of general liability and fluctuations at each time point over the 4-year period (i.e., between and within person effects). Moreover, results from multivariate multilevel path model were in line with the ecophenotype conceptualization. Indirect effects indicated that general liability of peer victimization mediated the effect of poor response inhibition on bullying perpetration. Likewise, general liability and concurrent fluctuations in hostility-related automatic thoughts and self-esteem mediated the effect of peer victimization on bullying perpetration. The current study highlights the need for a comprehensive understanding of bullying perpetration which is only possible through consideration of individual characteristics along with environmental factors. This framework has the potential to inform targeted intervention strategies aimed at reducing peer-to-peer violence.

A Population-Based Analysis of the Relationship Between Substance Use and Adolescent Cognitive Development

OBJECTIVE:nAlcohol and cannabis misuse are related to impaired cognition. When inferring causality, four nonexclusive theoretical models can account for this association: 1) a common underlying vulnerability model; 2) a neuroplasticity model in which impairment is concurrent with changes in substance use but temporary because of neuroplastic brain processes that restore function; 3) a neurotoxicity model of long-term impairment consequential to substance use; and 4) a developmental sensitivity hypothesis of age-specific effects. Using a developmentally sensitive design, the authors investigated relationships between year-to-year changes in substance use and cognitive development.nnnMETHOD:nA population-based sample of 3,826 seventh-grade students from 31 schools consisting of 5% of all students entering high school in 2012 and 2013 in the Greater Montreal region were assessed annually for 4 years on alcohol and cannabis use, recall memory, perceptual reasoning, inhibition, and working memory, using school-based computerized assessments. Multilevel regression models, performed separately for each substance, were used to simultaneously test vulnerability (between-subject) and concurrent and lagged within-subject effects on each cognitive domain.nnnRESULTS:nCommon vulnerability effects were detected for cannabis and alcohol on all domains. Cannabis use, but not alcohol consumption, showed lagged (neurotoxic) effects on inhibitory control and working memory and concurrent effects on delayed memory recall and perceptual reasoning (with some evidence of developmental sensitivity). Cannabis effects were independent of any alcohol effects.nnnCONCLUSIONS:nBeyond the role of cognition in vulnerability to substance use, the concurrent and lasting effects of adolescent cannabis use can be observed on important cognitive functions and appear to be more pronounced than those observed for alcohol.