Multi-site benchmark classification of major depressive disorder using machine learning on cortical and subcortical measures.

Machine learning (ML) techniques have gained popularity in the neuroimaging field due to their potential for classifying neuropsychiatric disorders. However, the diagnostic predictive power of the existing algorithms has been limited by small sample sizes, lack of representativeness, data leakage, and/or overfitting. Here, we overcome these limitations with the largest multi-site sample size to date (N = 5365) to provide a generalizable ML classification benchmark of major depressive disorder (MDD) using shallow linear and non-linear models. Leveraging brain measures from standardized ENIGMA analysis pipelines in FreeSurfer, we were able to classify MDD versus healthy controls (HC) with a balanced accuracy of around 62%. But after harmonizing the data, e.g., using ComBat, the balanced accuracy dropped to approximately 52%. Accuracy results close to random chance levels were also observed in stratified groups according to age of onset, antidepressant use, number of episodes and sex. Future studies incorporating higher dimensional brain imaging/phenotype features, and/or using more advanced machine and deep learning methods may yield more encouraging prospects.

Efficacy of a dialogic book-sharing intervention in a South African birth cohort: A randomized controlled trial.

OBJECTIVE: Evidence shows that dialogic book-sharing improves language development in young children in low-middle income countries (LMICs), particularly receptive and expressive language. It is unclear whether this intervention also boosts development of other neurocognitive and socio-emotional domains in children. Using a randomized controlled trial (RCT) nested in the Drakenstein Child Health Study (DCHS), a book-sharing intervention was implemented in caregivers of 3.5-year-old preschool children living in low-income South African communities. METHODS: 122 Caregivers and their children (mean age 3.5 years) were randomly assigned to an intervention group (n = 61) or waitlist control group (n = 61). A neurocognitive battery determined baseline receptive and expressive language, executive function, theory of mind, and behavior scores. RESULTS: No differences were observed between intervention and control groups on receptive and expressive language, or any of the neurocognitive or socio-emotional measures from baseline (3.5 years) to 4 months post-intervention administration (4 years). CONCLUSION: The benefits noted in prior literature of book-sharing in infants did not appear to be demonstrated at 4 months post-intervention, in children from 3.5 to 4 years of age. This suggests the importance of early intervention and emphasizes the need for further research on adaptation of book-sharing for older participants in a South African context. TRIAL REGISTRATION: retrospectively registered on 03/04/2022 PACTR202204697674974.

PTSD and comorbid MDD is associated with activation of the right frontoparietal network.

There is growing evidence of abnormalities in intrinsic functional connectivity (FC) in posttraumatic stress disorder (PTSD) and major depressive disorder (MDD). However, there has been less work on the commonly occurring co-presentation of PTSD and MDD. Characterising intrinsic FC abnormalities in this clinical population is important for understanding how they may contribute towards impairments underpinned by different networks. Participants were mothers enroled in the Drakenstein Child Health Study from Western Cape, South Africa. Mothers between 18 and 50 years of age were recruited and divided into 4 groups: PTSD, MDD, PTSD with MDD, and healthy controls. Participants underwent resting-state fMRI at the 18-month postpartum time point. Functional connectivity within and between higher order cognitive control networks, including the salience, dorsal attention, frontoparietal, and default mode networks were compared across the 4 groups. PTSD with comorbid MDD was associated with greater intrinsic FC within the R FPAR, relative to controls and the mono-diagnostic groups. Intrinsic FC differences were observed within the default mode network for the MDD group. No group differences in connectivity between networks were observed. Differential intrinsic connectivity in participants with comorbidity are consistent with evidence that such individuals have more severe illness and require more robust intervention.

Executive function in methamphetamine users with and without psychosis.

Methamphetamine abuse is associated with cognitive deficits across a wide range of domains. It is unclear, however, whether methamphetamine-dependent individuals with co-occurring psychosis are more impaired than those without psychosis on tests assessing executive function. We therefore aimed to compare the executive function performance of three groups: methamphetamine-dependent individuals with methamphetamine-induced psychosis (MA+; n = 20), methamphetamine-dependent individuals without psychosis (MA-; n = 19), and healthy controls (HC; n = 20). All participants were administered a neuropsychological test battery that assessed executive functioning across six sub domains (problem solving, working memory, verbal generativity, inhibition, set switching, and decision making). Analyses of covariance (controlling for between-group differences in IQ) detected significant between-group differences on tests assessing verbal generativity and inhibition, with MA+ participants performing significantly more poorly than HC. The finding that methamphetamine-induced psychosis is associated with performance impairments in particular subdomains of executive function may have implications for treatment adherence and relapse prevention.

Antenatal maternal depression, early life inflammation and neurodevelopment in a South African birth cohort.

BACKGROUND: Antenatal exposure to maternal psychological adversity, including depression, increases the risk of impaired neurodevelopment in children. The underlying biological mechanisms remain unclear, especially in early life during critical windows of development and maturation. This study investigated the association of antenatal maternal depression, maternal and early life inflammatory markers and neurodevelopmental outcomes in children at 2 years of age. METHODS: A subgroup of mothers and their children (n = 255) that were enrolled in a South African birth cohort study, the Drakenstein Child Health Study, were followed from the antenatal period through to 2 years of child age. Maternal depressive symptoms were measured by the Beck Depression Inventory (BDI-II) at 26 weeks gestation. Serum inflammatory markers [granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-γ (IFN-γ), interleukin IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, tumour necrosis factor-α (TNF-α), neutrophil gelatinase-associated lipocalin (NGAL) and metalloproteinase-9 (MMP-9)] were measured in mothers at enrolment and in their children at 6-10 weeks and at 2 years. Neurodevelopment was assessed at 2 years using the Bayley Scales of Infant and Toddler Development III. RESULTS: Antenatal depressive symptoms (present in 25% of the mothers) were significantly associated with higher levels of IL-7 (p = 0.008), IL-8 (p = 0.019) and TNF-α (p = 0.031) in the mothers after correcting for sociodemographic and lifestyle factors. Serum IL-1ß and NGAL levels were significantly elevated over time in children born to mothers with depressive symptoms compared to those without depression, after controlling for maternal and child health and sociodemographic factors. Elevated infant IL-1ß at 6-10 weeks of age partially mediated the association of maternal depressive symptoms with poorer language scores at 2 years. CONCLUSION: Alterations in early life immunity, as reflected by elevated IL-1ß, is a potential pathway through which antenatal maternal depressive symptoms may impact language development in young children.

Coulrophobia: An investigation of clinical features.

BACKGROUND: Coulrophobia refers to fear or disgust elicited by clowns, or images of clowns, and may be accompanied by significant distress. The medical literature on sociodemographic and clinical features of coulrophobia is, however, sparse. AIM: This study aimed to investigate coulrophobia sociodemographic and clinical features in an online support group. SETTING: A self-administered questionnaire was distributed to an online support group for coulrophobia. METHODS: Members of the online coulrophobia support group received a link to a self-administered questionnaire. The questionnaire focused on sociodemographic and clinical features, including fear-related and disgust-related symptoms, and included DSM-5 diagnostic criteria for specific phobia. RESULTS: Of the 95 survey respondents, 79 were female respondents (mean age: 39.8 ± 12.6 years), with the mean age of onset 9 ± 6.1 years. Coulrophobia symptoms were associated with significant psychological distress and with impaired social functioning. About 7.4% of respondents reported severe anxiety with panic attacks. Comorbid disorders included major depressive disorder (9.5%), obsessive-compulsive disorder (5.3%) and panic disorder (3.2%). Individuals with fear-related symptoms were more likely to fulfil DSM-5 criteria for specific phobia. CONCLUSION: Coulrophobia is a phenomenon that warrants clinical attention, given its association with significant comorbidity, psychological distress and impaired functioning. Several sociodemographic and clinical features are consistent with a diagnosis of specific phobia, although future work employing clinician-administered diagnostic tools is needed to consolidate and extend the findings here.

Perinatal suicidality: prevalence and correlates in a South African birth cohort.

Suicidal ideation and behaviour (SIB) in the perinatal period is prevalent in low- and middle-income countries (LMICs). Past work has been limited by reliance on self-rated scales, and there are few data on SIB severity in such settings. We collected cross-sectional data on SIB using a clinician-administered scale and explored risk factors associated with the presence of SIB and SIB severity. Data were collected from the Drakenstein Child Health Study cohort antenatally and at 6 months postpartum. SIB was measured using the Mini International Neuropsychiatric Interview, and potential sociodemographic, psychosocial, and psychiatric risk factors were assessed. Multivariable analysis determined cross-sectional risk factors. Multinomial regressions determined predictors of SIB risk categories. Among 748 women, the antenatal SIB prevalence was 19.9% and postpartum 22.6%. SIB was associated with younger age (antepartum), PTSD (postpartum), and depression (ante- and postpartum). Depression and PTSD predicted belonging to the high-risk SIB group. The medium-risk group was more likely to have depression, alcohol use during pregnancy, and substance abuse. Depression, PTSD, food insecurity, recent intimate partner violence (IPV), and childhood trauma were associated with the low-risk group versus the no-risk group. Screening is needed for perinatal SIB. Associations of perinatal SIB with younger age and major depression are consistent with previous work. The association with PTSD is novel, and underscores the importance of assessment of trauma exposure and outcomes in this population. Different risk categories of SIB may have different causal pathways and require different interventions.

The neurocognitive profile of post-traumatic stress disorder (PTSD), major depressive disorder (MDD), and PTSD with comorbid MDD.

OBJECTIVE: Neurocognitive dysfunction has been associated with post-traumatic stress disorder (PTSD) and major depressive disorder (MDD). However, although PTSD is often comorbid with MDD, there is little neurocognitive work to date on individuals who suffer from both PTSD and MDD. Here, we compared neurocognitive domains in individuals with PTSD, MDD, and comorbid PTSD and MDD with those of healthy controls. METHODS: Participants comprised of mothers enrolled in the Drakenstein Child Health Study, a study exploring child health determinants in the Drakenstein district, Western Cape. N = 175 mothers (between 18 and 50 years) were recruited and divided into 4 groups: PTSD, MDD, PTSD with MDD, and healthy controls. Participants were assessed using the computerized NIH Toolbox, and paper and pencil neurocognitive tests. Domains assessed included executive function, memory, attention, learning, and processing speed. RESULTS: Distinct patterns of neurocognitive dysfunction were observed in this sample. PTSD was associated with more intrusion errors and MDD was associated with delayed recall impairment, relative to healthy controls. PTSD with comorbid MDD was associated with processing speed impairments, relative to healthy controls, and monodiagnostic groups. No group differences were observed on measures of attention and executive function. CONCLUSION: Distinct patterns of neurocognitive dysfunction were associated with diagnoses of MDD and PTSD. Greater anticipated dysfunction and impairment in comorbid PTSD and MDD was not observed, however. Further work is needed to replicate and extend these findings.

Methamphetamine and cannabis abuse in adolescence: a quasi-experimental study on specific and long-term neurocognitive effects.

OBJECTIVES: Methamphetamine abuse affects brain structure and function. Although methamphetamine and cannabis are commonly abused together, few studies have investigated the differential neurocognitive consequences of methamphetamine abuse with or without cannabis. Furthermore, the effects of drug use on the developing adolescent brain remain poorly understood. We compared neurocognitive function between adolescents with 'pure' methamphetamine abuse, those with comorbid methamphetamine and cannabis abuse, and healthy controls at baseline and follow-up. METHODS: Individuals residing in the greater Cape Town region, between the ages of 13 and 18 years, were recruited into either Methamphetamine only group (Meth-only; n=10), Methamphetamine and cannabis group (Meth-cann; n=10) or healthy control (n=20) groups using a quasi-experimental design. All participants underwent a comprehensive neurocognitive assessment. Substance-use variables and psychiatric symptom counts were also recorded. A portion of the Meth-only and control participants completed 12-month follow-up assessments. RESULTS: While the Meth-cann group demonstrated widespread neurocognitive deficits at baseline, these deficits were restricted to the self-monitoring domain in the Meth-only group at baseline and at follow-up. CONCLUSIONS: Methamphetamine abuse with cannabis abuse is associated with significantly more neurocognitive impairment than methamphetamine abuse alone, and such deficits may be enduring.