Treatment-resistant depression (TRD) represents a major clinical challenge characterised by inadequate response to conventional antidepressant therapies and high relapse rates. Emerging evidence suggests that TRD may extend beyond monoaminergic dysfunction and may involve dysregulation of the HPA axis, neuroinflammation, impaired neuroplasticity, and disruption of the gut-brain axis (GBA). Gut dysbiosis has been associated with treatment resistance through alterations in monoamine turnover, immune signalling, intestinal barrier integrity, and drug-microbiome interactions affecting antidepressant bioavailability. This review integrates emerging evidence supporting targeted modulation of the GBA as a mechanistically informed strategy for TRD. Specific microbial strains (e.g., Christensenella minuta, Akkermansia muciniphila, Bifidobacterium breve CCFM1025), microbial metabolites (e.g., indole-3-propionic acid, indole-3-lactic acid, anserine), and phytochemicals (e.g., curcumin, matrine, salidroside) are discussed for their proposed roles in modulating neuroendocrine signalling, neuroinflammation, and synaptic plasticity. The review also highlights emerging peripheral biomarkers, including the kynurenine/tryptophan ratio, serum metabolomics, and lymphocyte serotonin transporter clustering, as candidate tools for stratified psychiatry. Most of the evidence discussed in this review comes from animal studies, in vitro systems, and computational analyses, while direct evidence in patients with treatment-resistant depression remains limited. These findings provide important mechanistic insights into gut-brain axis dysfunction but require further validation in human TRD populations. Biomarker-guided and endotype-based approaches targeting the gut-brain axis may offer a useful framework for future research, although their clinical utility has yet to be established.

Assessment of Attention-Deficit/Hyperactivity Disorder (ADHD) among adults is complicated by high psychiatric comorbidity and symptom overlap, increasing the risk of potential diagnostic misclassification. This study used a Three-Step Latent Profile Analysis (LPA) to identify distinct Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF), Restructured Clinical (RC) scale profiles in a mixed clinical sample seeking ADHD evaluation (n = 546). Three latent profiles emerged: a low-symptom profile, a somatic-depressed-threat sensitive profile, and a primarily demoralized profile. Profiles were not associated with ADHD diagnosis alone or most ADHD comorbidities. However, the profiles differed significantly in the probability of depression diagnoses, anxiety diagnoses, and combined ADHD/depression/anxiety diagnoses. Findings suggest MMPI-2-RF RC scale profiles are informative for identifying internalizing psychopathology and diagnostic complexity but lack specificity for ADHD. Results underscore the utility of MMPI-2-RF, RC scale-based latent profiles in disentangling diagnostic heterogeneity and the importance of multimethod assessment in adult ADHD evaluations.

Social media platforms are central to daily social interaction, with emerging evidence linking higher engagement to adverse outcomes, including increased stress, sleep disturbance, and depressive symptoms. However, whether these digital exposures translate into measurable acceleration of biological aging remains unexplored, particularly among midlife and older adults. We analyzed cross-sectional data from 323 participants (Mean age = 47.5 years, SD = 11.8) in the Midlife in the United States Refresher Study who completed daily diary assessments of social media use duration and provided blood samples for epigenetic aging measurement. Epigenetic aging was quantified using DunedinPACE and GrimAge2 from genome-wide DNA methylation analysis. In a linear regression model controlling for differences in inter-assessment intervals, sociodemographic characteristics, health behaviors, and self-reported mental health, each additional hour of daily social media use was significantly associated with a 0.19-SD higher DunedinPACE score (95% CI: 0.08 to 0.29, p < 0.001). However, further adjustment for body mass index attenuated this association (0.09 SD increase, 95% CI: -0.01, 0.19, p = 0.088), suggesting that BMI may reflect the downstream consequences of broader behavioral, metabolic, psychosocial, environmental, and health-related processes relevant to the observed relationship. No associations were observed with GrimAge2 across any model. These findings provide preliminary evidence that social media use duration is associated with the pace of biological aging as measured by DunedinPACE. Future research should employ longitudinal designs with direct measurement of digital engagement, behavioral and psychosocial processes, and physiological mechanisms to clarify how digital environments may relate to biological aging over time.

There is a recognized need for efforts that promote utilization and completion of trauma-focused evidence-based psychotherapies (EBPs) for posttraumatic stress disorder (PTSD). Patients referred to PTSD specialty clinics are often reluctant to engage in EBPs, especially if they are treatment-naive or had prior negative treatment experiences. To address this reluctance, we implemented PTSD101, a psychoeducation group led by peer specialists offered in a specialty PTSD clinic for veterans considering new PTSD services. This present study aimed to conduct a program evaluation of PTSD101 using pre-post data. The structured group consisted of seven 90-min sessions addressing: (a) civilian readjustment; (b) effects of trauma; (c) trust, safety, and self-care; (d) coping/healing; (e) survival strategies and relationships; (d) substance use and medication; and (f) PTSD treatment. Data were collected from 34 veterans across multiple group cohorts. Following completion of the group, over half of the veterans (n = 18) initiated a new behavioral health treatment service, including trauma-focused EBPs (n = 11). Significant improvements were also noted in measures of PTSD symptoms, depression symptoms, and illness management strategies and recovery outcomes. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

This article examines how mental health practitioners in Aotearoa New Zealand understand the ways historical trauma, particularly child sexual abuse (CSA), surfaces in their work with young Sāmoan women who present with depression. Drawing on talanoa with 16 mental health practitioners supporting Sāmoan women aged 18-24, the study identifies a consistent pattern: depression often masks long-silenced experiences of CSA. Disclosures typically emerge after several years of silence, shaped by cultural and familial norms that restrict conversations about sexual harm within Sāmoan communities. Practitioners described recognising trauma through relational and culturally attuned engagement rather than direct disclosure. Their accounts echo international evidence on delayed CSA disclosure among minoritised populations, while highlighting the cultural factors shaping help-seeking for Sāmoan women. By centring practitioners' interpretations, the study underscores the need for trauma-informed, culturally grounded mental health responses that acknowledge both shared and culturally specific dimensions of silence, disclosure and healing. Strengthening practitioners' capacity to recognise and respond to hidden trauma is critical for supporting young Sāmoan women whose experiences often remain unrecognised within mental health systems. The findings also emphasise the importance of locally grounded approaches, recognising that while patterns may echo across Pacific communities, pathways to healing must remain culturally specific.