Outcomes of Best-Practice Guided Digital Mental Health Interventions for Youth and Young Adults with Emerging Symptoms: Part II. A Systematic Review of User Experience Outcomes.

Although many young people demonstrate resilience and strength, research and clinical evidence highlight an upward trend in mental health concerns among those aged 12 to 25 years. Youth-specific digital mental health interventions (DMHIs) aim to address this trend by providing timely access to mental health support for young people (12-25 years). However, there is a considerable gap in understanding young people user experiences with digital interventions. This review, co-designed with Australia's leading mental health organization Beyond Blue, utilizes a systematic methodology to synthesize evidence on user experience in youth-oriented digital mental health interventions that are fully or partially guided. Five relevant online databases were searched for articles published from 2018 to 2023, yielding 22,482 articles for screening and 22 studies were included in the present analysis. User experience outcomes relating to satisfaction and engagement were assessed for each included intervention, with experience indicators relating to usefulness, usability, value, credibility, and desirability being examined. Elements associated with positive/negative outcomes were extracted. Elements shown to positively influence user experience included peer engagement, modern app-based delivery, asynchronous support, and personalized content. In contrast, users disliked static content, homework/log-keeping, the requirement for multiple devices, and social media integration. Asynchronous interventions showed high satisfaction but faced engagement issues, with combined asynchronous/synchronous interventions reporting better completion rates. DMHIs offer a promising platform for youth mental health support and has the potential to dramatically increase the reach of interventions through the adoption of technological and user experience best practices. While young people respond positively to many aspects of intervention modernization, such as interactive, app-based design, other concepts, such as social media integration, they need to be adopted by the field more cautiously to ensure trust and engagement.Trial Registration CRD42023405812.

Universal Digital Programs for Promoting Mental and Relational Health for Parents of Young Children: A Systematic Review and Meta-Analysis.

Digital parenting programs aim to increase program access, improve psychosocial outcomes for parents and children, and support triage to targeted interventions where required. This meta-analysis assessed the efficacy of online parenting programs in improving parenting skills and capabilities, and by consequence, the mental health and well-being of parents and children, and the quality of the parent-child relationship. Studies were included if they were: (1) online, (2) self-delivered, (3) designed for universal general population prevention, (4) evaluated experimental or quasi-experimental designs, and (5) assessed parent and child emotional and/or relational health, from pregnancy to 5 years of age. A systematic search of electronic databases and grey literature identified 22 studies that met inclusion criteria, including 24 independent samples, with 5671 unique parents. Meta-analyses were conducted using random effects models and Cohen's d effects. Small-to-moderate improvements in parent depression, anxiety, self-efficacy, and social support were observed. No effects on parent stress, satisfaction, or parent-child relationship quality were observed. Meta-regression and sub-group analysis were conducted to identify sensitivity or moderation effects. Collectively, findings suggest any benefits of online parenting programs mostly occur at the time of the intervention, for parent mental health and well-being outcomes, and that enduring effects are unlikely. However, given the cost effectiveness and accessibility of online programs, further research into ways of sustaining effects on parenting outcomes is warranted. Furthermore, given the centrality of the parent-child bond to child development across the lifecourse, additional investment in new digitally facilitated approaches focusing on this bond are likewise warranted.PROSPERO registration CRD42021275647.

Early childhood attachment stability and change: a meta-analysis.

Examining degrees of stability in attachment throughout early childhood is important for understanding developmental pathways and for informing intervention. Updating and building upon all prior meta-analyses, this study aimed to determine levels of stability in all forms of attachment classifications across early childhood. Attachment stability was assessed between three developmental epochs within early childhood: infancy, toddlerhood, and preschool/early school. To ensure data homogeneity, only studies that assessed attachment with methods based on the strange situation procedure were included. Results indicate moderate levels of stability at both the four-way (secure, avoidant, resistant, and disorganised; κ = 0.23) and secure/insecure (r = 0.28) levels of assessment. Meta-regression analysis indicated security to be the most stable attachment organisation. This study also found evidence for publication bias, highlighting a preference for the publication of significant findings.

Minimizing axon bundle activation of retinal ganglion cells with oriented rectangular electrodes.

OBJECTIVE: Retinal prostheses aim to restore vision in patients with retinal degenerative diseases, such as age-related macular degeneration and retinitis pigmentosa. By implanting an array of microelectrodes, such a device creates percepts in patients through electrical stimulation of surviving retinal neurons. A challenge for retinal prostheses when trying to return high quality vision is the unintended activation of retinal ganglion cells through the stimulation of passing axon bundles, which leads to patients reporting large, elongated patches of light instead of focal spots. APPROACH: In this work, we used calcium imaging to record the responses of retinal ganglion cells to electrical stimulation in explanted retina using rectangular electrodes placed with different orientations relative to the axon bundles. MAIN RESULTS: We showed that narrow, rectangular electrodes oriented parallel to the axon bundles can achieve focal stimulation. To further improve the strategy, we studied the impact of different stimulation waveforms and electrode configurations. We found the selectivity for focal stimulation to be higher when using short (33 µs), anodic-first biphasic pulses, with long electrode lengths and at least 50 µm electrode-to-retinal separation. Focal stimulation was, in fact, less selective when the electrodes made direct contact with the retinal surface due to unwanted preferential stimulation of the proximal axon bundles. SIGNIFICANCE: When employed in retinal prostheses, the proposed stimulation strategy is expected to provide improved quality of vision to the blind.

Biophysical basis of the linear electrical receptive fields of retinal ganglion cells.

Responses of retinal ganglion cells to direct electrical stimulation have been shown experimentally to be well described by linear-nonlinear models. These models rely on the simplifying assumption that retinal ganglion cell responses to stimulation with an array of electrodes are driven by a simple linear weighted sum of stimulus current amplitudes from each electrode, known as the 'electrical receptive field'. OBJECTIVE: This paper aims to demonstrate the biophysical basis of the linear-nonlinear model and the electrical receptive field to facilitate the development of improved stimulation strategies for retinal implants. APPROACH: We compare the linear-nonlinear model of subretinal electrical stimulation with a multi-layered, biophysical, volume conductor model of retinal stimulation. MAIN RESULTS: Our results show that the linear electrical receptive field of the linear-nonlinear model matches the transmembrane currents induced by electrodes (the activating function) at the site of the high-density sodium channel band with only minor discrepancies. The discrepancies are mostly eliminated by including axial current flow originating from adjacent cell compartments. Furthermore, for cells where a single linear electrical receptive field is insufficient, we show that cell responses are likely driven by multiple sites of action potential initiation with multiple distinct receptive fields, each of which can be accurately described by the activating function. SIGNIFICANCE: This result establishes that the biophysical basis of the electrical receptive field of the linear-nonlinear model is the superposition of transmembrane currents induced by different electrodes at and near the site of action potential initiation. Together with existing experimental support for linear-nonlinear models of electrical stimulation, this provides a firm basis for using this much simplified model to generate more optimal stimulation patterns for retinal implants.

Minimizing activation of overlying axons with epiretinal stimulation: The role of fiber orientation and electrode configuration.

Currently, a challenge in electrical stimulation of the retina with a visual prosthesis (bionic eye) is to excite only the cells lying directly under the electrode in the ganglion cell layer, while avoiding excitation of axon bundles that pass over the surface of the retina in the nerve fiber layer. Stimulation of overlying axons results in irregular visual percepts, limiting perceptual efficacy. This research explores how differences in fiber orientation between the nerve fiber layer and ganglion cell layer leads to differences in the electrical activation of the axon initial segment and axons of passage. APPROACH: Axons of passage of retinal ganglion cells in the nerve fiber layer are characterized by a narrow distribution of fiber orientations, causing highly anisotropic spread of applied current. In contrast, proximal axons in the ganglion cell layer have a wider distribution of orientations. A four-layer computational model of epiretinal extracellular stimulation that captures the effect of neurite orientation in anisotropic tissue has been developed using a volume conductor model known as the cellular composite model. Simulations are conducted to investigate the interaction of neural tissue orientation, stimulating electrode configuration, and stimulation pulse duration and amplitude. MAIN RESULTS: Our model shows that simultaneous stimulation with multiple electrodes aligned with the nerve fiber layer can be used to achieve selective activation of axon initial segments rather than passing fibers. This result can be achieved while reducing required stimulus charge density and with only modest increases in the spread of activation in the ganglion cell layer, and is shown to extend to the general case of arbitrary electrode array positioning and arbitrary target volume. SIGNIFICANCE: These results elucidate a strategy for more targeted stimulation of retinal ganglion cells with experimentally-relevant multi-electrode geometries and achievable stimulation requirements.

A computational model of orientation-dependent activation of retinal ganglion cells.

Currently, a challenge in electrical stimulation for epiretinal prostheses is the avoidance of stimulation of axons of passage in the nerve fiber layer that originate from distant regions of the ganglion cell layer. A computational model of extracellular stimulation that captures the effect of neurite orientation in anisotropic tissue is developed using a modified version of the standard volume conductor model, known as the cellular composite model, embedded in a four layer model of the retina. Simulations are conducted to investigate the interaction of neural tissue orientation, electrode placement, and stimulation pulse duration and amplitude. Using appropriate multiple electrode configurations and higher frequency stimulation, preferential activation of the axon initial segment is shown to be possible for a range of realistic electrode-retina separation distances. These results establish a quantitative relationship between the time-course of stimulation and physical properties of the tissue, such as fiber orientation.