Narrative analysis in individuals with Parkinson's disease following intensive voice treatment: secondary outcome variables from a randomized controlled trial.

Communication is often impaired in individuals with Parkinson's disease (PD), typically secondary to sensorimotor deficits impacting voice and speech. Language may also be diminished in PD, particularly for production and comprehension of verbs. Evidence exists that verb processing is influenced by motor system modulation suggesting that verb deficits in PD are underpinned by similarities in the neural representations of actions that span motor and semantic systems. Conversely, subtle differences in cognition in PD may explain difficulty in processing of complex syntactic forms, which increases cognitive demand and is linked to verb use. Here we investigated whether optimizing motor system support for vocal function (improving loudness) affects change in lexical semantic, syntactic, or informativeness aspects of spoken discourse. Picture description narratives were compared for 20 Control participants and 39 with PD, 19 of whom underwent Lee Silverman Voice Treatment (LSVT LOUD®). Treated PD narratives were also contrasted with those of untreated PD and Control participants at Baseline and after treatment. Controls differed significantly from the 39 PD participants for verbs per utterance, but this difference was largely driven by untreated PD participants who produced few utterances but with verbs, inflating their verbs per utterance. Given intervention, there was a significant increase in vocal loudness but no significant changes in language performance. These data do not support the hypothesis that targeting this speech motor system results in improved language production. Instead, the data provide evidence of considerable variability in measures of language production across groups, particularly in verbs per utterance.

Intensive Voice Treatment (Lee Silverman Voice Treatment [LSVT LOUD]) for Children With Down Syndrome: Phase I Outcomes.

PURPOSE: This study examined the effects of an intensive voice treatment Lee Silverman Voice Treatment (LSVT LOUD) on children with Down syndrome (DS) and motor speech disorders. METHOD: A Phase I, multiple baseline, single-subject design with replication across nine participants with DS was used. Single-word intelligibility, acoustic measures of vocal functioning, and parent perceptions of pre- and posttreatment communication function were used as treatment outcome measures. RESULTS: All participants completed the full dose of LSVT LOUD and showed gains on one or more of the outcome measures. Patterns of posttreatment improvements were not consistent across participants but were more frequently observed on trained maximum performance tasks compared to tasks reflecting generalization of the treatment skillset. Some participants exhibited a stronger response to treatment, whereas others showed a mixed or weaker response. Parents liked the treatment protocol, perceived benefits from intensive intervention, and indicated they would strongly recommend LSVT LOUD to other parents who have children with DS and motor speech disorders. CONCLUSIONS: These preliminary results show that children with DS tolerated intensive voice treatment without adverse effects and made select meaningful therapeutic gains. The treatment evidence from this study warrants Phase II treatment studies using LSVT LOUD with a larger group of children with DS.

Nursing Skills Video Selfies: An Innovative Teaching and Learning Strategy for Undergraduate Nursing Students to Master Psychomotor Skills.

INTRODUCTION: The quality of care for patients is linked to the performance and competence of nurses. Nurse educators are challenged to prepare graduates to deliver safe, competent, patient-centered care. Nursing skills video "selfie" is an innovative teaching and learning strategy in which nursing students use technology to create videos of themselves (video selfie) performing psychomotor skills. METHOD: The instructional exercise of creating the video selfie was administered to a group of nursing students in a medical-surgical class. The laboratory instructors identified three psychomotor nursing skills. In the skills lab, the instructors showed videos to demonstrate how the skills were performed. The students returned demonstration in the lab and were asked to return to the lab independently to practice the skills and to create a video selfie. RESULTS: The exercise encouraged students to increase the quality and length of practice and master the skill. Students demonstrated confidence to perform the skills and to accurately list each step required to perform the skills. The video selfie was used as a peer evaluation tool and as a faculty assessment tool to guide individual students' instruction, learning, and remediation. CONCLUSION: The exercise had some shortcomings. Future quantitative research using survey instruments to collect data from a larger group of nursing students is needed to validate the utility of this innovative teaching and learning strategy in nursing programs.

Speech treatment in Parkinson's disease: Randomized controlled trial (RCT).

BACKGROUND: As many as 89% of people with Parkinson's disease (PD) develop speech disorders. OBJECTIVES: This randomized controlled trial evaluated two speech treatments for PD matched in intensive dosage and high-effort mode of delivery, differing in subsystem target: voice (respiratory-laryngeal) versus articulation (orofacial-articulatory). METHODS: PD participants were randomized to 1-month LSVT LOUD (voice), LSVT ARTIC (articulation), or UNTXPD (untreated) groups. Speech clinicians specializing in PD delivered treatment. Primary outcome was sound pressure level (SPL) in reading and spontaneous speech, and secondary outcome was participant-reported Modified Communication Effectiveness Index (CETI-M), evaluated at baseline, 1, and 7 months. Healthy controls were matched by age and sex. RESULTS: At baseline, the combined PD group (n = 64) was significantly worse than healthy controls (n = 20) for SPL (P < 0.05) and CETI-M (P = 0.0001). At 1 and 7 months, SPL between-group comparisons showed greater improvements for LSVT LOUD (n = 22) than LSVT ARTIC (n = 20; P < 0.05) and UNTXPD (n = 22; P < 0.05). Sound pressure level differences between LSVT ARTIC and UNTXPD at 1 and 7 months were not significant (P > 0.05). For CETI-M, between-group comparisons showed greater improvements for LSVT LOUD and LSVT ARTIC than UNTXPD at 1 month (P = 0.02; P = 0.02). At 7 months, CETI-M between-group differences were not significant (P = 0.08). Within-group CETI-M improvements for LSVT LOUD were maintained through 7 months (P = 0.0011). CONCLUSIONS: LSVT LOUD showed greater improvements than both LSVT ARTIC and UNTXPD for SPL at 1 and 7 months. For CETI-M, both LSVT LOUD and LSVT ARTIC improved at 1 month relative to UNTXPD. Only LSVT LOUD maintained CETI-M improvements at 7 months. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Changes in White Matter Integrity following Intensive Voice Treatment (LSVT LOUD®) in Children with Cerebral Palsy and Motor Speech Disorders.

Preliminary evidence suggests that intensive voice and speech treatment based on activity-dependent neuroplasticity principles holds promise for affecting positive change in children with cerebral palsy (CP) and motor speech disorders. Diffusion tensor imaging (DTI) allows researchers to make inferences about the integrity of white matter tracks and provides a sensitive measure of neuroplasticity. Previous treatment studies looking at the effects of training on white matter integrity have shown positive results, but these studies have been limited to gross motor function. Eight children with motor speech disorders and CP (3 females; age 8-16 years) and an age- and sex-matched group of typically developing (TD) children participated. Each child with CP completed a full dose of LSVT LOUD® and a 12-week maintenance program. Participants attended 3 recording sessions: before and after treatment, and after the maintenance period. TD children were tested at the same 3 time points. Recording sessions for both groups of children included measures of white matter integrity using DTI and acoustic measures of voice and speech. Fractional anisotropy (FA) was measured for 2 motor tracts and 5 association tracts. In children with CP, we observed an increase in FA in several motor and association tracts immediately following treatment and 12 weeks after treatment. Acoustic data on untrained tasks were correlated with changes in FA detected immediately following treatment and after the 12-week maintenance program. These findings suggest that long-term practice of skills attained during the treatment phase enhances white matter tract integrity in speech production networks.

Changes in brain activity following intensive voice treatment in children with cerebral palsy.

Eight children (3 females; 8-16 years) with motor speech disorders secondary to cerebral palsy underwent 4 weeks of an intensive neuroplasticity-principled voice treatment protocol, LSVT LOUD® , followed by a structured 12-week maintenance program. Children were asked to overtly produce phonation (ah) at conversational loudness, cued-phonation at perceived twice-conversational loudness, a series of single words, and a prosodic imitation task while being scanned using fMRI, immediately pre- and post-treatment and 12 weeks following a maintenance program. Eight age- and sex-matched controls were scanned at each of the same three time points. Based on the speech and language literature, 16 bilateral regions of interest were selected a priori to detect potential neural changes following treatment. Reduced neural activity in the motor areas (decreased motor system effort) before and immediately after treatment, and increased activity in the anterior cingulate gyrus after treatment (increased contribution of decision making processes) were observed in the group with cerebral palsy compared to the control group. Using graphical models, post-treatment changes in connectivity were observed between the left supramarginal gyrus and the right supramarginal gyrus and the left precentral gyrus for the children with cerebral palsy, suggesting LSVT LOUD enhanced contributions of the feedback system in the speech production network instead of high reliance on feedforward control system and the somatosensory target map for regulating vocal effort. Network pruning indicates greater processing efficiency and the recruitment of the auditory and somatosensory feedback control systems following intensive treatment. Hum Brain Mapp 38:4413-4429, 2017. © 2017 Wiley Periodicals, Inc.

Therapeutic effects of intensive voice treatment (LSVT LOUD®) for children with spastic cerebral palsy and dysarthria: A phase I treatment validation study.

PURPOSE: The aim of the present study was to validate and extend the evaluation of treatment outcomes following LSVT LOUD® in children with dysarthria secondary to cerebral palsy (CP). METHOD: Seven children (5 females, 6-10 years) with spastic quadriplegia and dysarthria received LSVT LOUD. Outcomes included: (a) quantitative and qualitative indices of communication and social functioning representing therapeutic effects and (b) features of the acoustic signal representing physiological effects on the speech mechanism. A matched group of typically developing children served as controls. Testing occurred just prior to (PRE), immediately following (POST), and at 12 weeks post-treatment (FUP). RESULT: Expert listeners preferred voice quality and articulatory precision of children with CP at FUP as compared to PRE. Acoustic data indicated improvements on select measures of vocal functioning at POST with some maintenance at FUP. Single word intelligibility improved immediately POST, but was not maintained at FUP. Parents rated positive changes in characteristics of voice and speech and qualitative changes in communication at both POST and FUP. CONCLUSION: The present study validated some of the previous LSVT LOUD outcomes in children with dysarthria and CP and extended our understanding of therapeutic effects through qualitative data obtained from extensive parent interviews.

Reduced vocal variability in a zebra finch model of dopamine depletion: implications for Parkinson disease.

Midbrain dopamine (DA) modulates the activity of basal ganglia circuitry important for motor control in a variety of species. In songbirds, DA underlies motivational behavior including reproductive drive and is implicated as a gatekeeper for neural activity governing vocal variability. In the zebra finch, Taeniopygia guttata, DA levels increase in Area X, a song-dedicated subregion of the basal ganglia, when a male bird sings his courtship song to a female (female-directed; FD). Levels remain stable when he sings a less stereotyped version that is not directed toward a conspecific (undirected; UD). Here, we used a mild dose of the neurotoxin 6-hydroxydopamine (6-OHDA) to reduce presynaptic DA input to Area X and characterized the effects on FD and UD behaviors. Immunoblots were used to quantify levels of tyrosine hydroxylase (TH) as a biomarker for DA afferent loss in vehicle- and 6-OHDA-injected birds. Following 6-OHDA administration, TH signals were lower in Area X but not in an adjacent subregion, ventral striatal-pallidum (VSP). A postsynaptic marker of DA signaling was unchanged in both regions. These observations suggest that effects were specific to presynaptic afferents of vocal basal ganglia. Concurrently, vocal variability was reduced during UD but not FD song. Similar decreases in vocal variability are observed in patients with Parkinson disease (PD), but the link to DA loss is not well-understood. The 6-OHDA songbird model offers a unique opportunity to further examine how DA loss in cortico-basal ganglia pathways affects vocal control.

Evidence-based treatment of voice and speech disorders in Parkinson disease.

PURPOSE OF REVIEW: Voice and speech impairments are present in nearly 90% of people with Parkinson disease and negatively impact communication and quality of life. This review addresses the efficacy of Lee Silverman Voice Treatment (LSVT) LOUD to improve vocal loudness (as measured by vocal sound pressure level vocSPL) and functional communication in people with Parkinson disease. The underlying physiologic mechanisms of Parkinson disease associated with voice and speech changes and the strength of the current treatment evidence are discussed with recommendations for best clinical practice. RECENT FINDINGS: Two randomized control trials demonstrated that participants who received LSVT LOUD were significantly better on the primary outcome variable of improved vocSPL posttreatment than alternative and no treatment groups. Treatment effects were maintained for up to 2 years. In addition, improvements have been demonstrated in associated outcome variables, including speech rate, monotone, voice quality, speech intelligibility, vocal fold adduction, swallowing, facial expression and neural activation. Advances in technology-supported treatment delivery are enhancing treatment accessibility. SUMMARY: Data support the efficacy of LSVT LOUD to increase vocal loudness and functional communication in people with Parkinson disease. Timely intervention is essential for maximizing quality of life for people with Parkinson disease.

Individual and environmental contributions to treatment outcomes following a neuroplasticity-principled speech treatment (LSVT LOUD) in children with dysarthria secondary to cerebral palsy: a case study review.

This study describes the use of a neuroplasticity-principled speech treatment approach (LSVT(®)LOUD) with children who have dysarthria secondary to cerebral palsy. To date, the authors have treated 25 children with mild-to-severe dysarthria, a continuum of gross and fine motor functions, and variable cognitive abilities. From this data set, two case studies are presented that represent as weak or strong responders to LSVT LOUD. These case studies demonstrate how individual and environmental features may impact immediate and lasting responses to treatment. Principles that drive activity-dependent neuroplasticity are embedded in LSVT LOUD and may contribute to positive therapeutic and acoustic outcomes. However, examination of the response patterns indicated that intensity (within and across treatment sessions) is necessary but not sufficient for change. Weak responders may require a longer treatment phase, better timing (e.g., developmentally, socially), and a more prominent desire to communicate successfully during daily activities. Strong responders appear to benefit from the intensity and saliency of treatment as well as from intrinsic and extrinsic rewards for using the trained skills for everyday communication. Finally, possibilities are presented for technological solutions designed to promote accessibility to the intensive task repetition and maintenance required to drive lasting changes.

Robust fundamental frequency estimation in sustained vowels: detailed algorithmic comparisons and information fusion with adaptive Kalman filtering.

There has been consistent interest among speech signal processing researchers in the accurate estimation of the fundamental frequency (F(0)) of speech signals. This study examines ten F(0) estimation algorithms (some well-established and some proposed more recently) to determine which of these algorithms is, on average, better able to estimate F(0) in the sustained vowel /a/. Moreover, a robust method for adaptively weighting the estimates of individual F(0) estimation algorithms based on quality and performance measures is proposed, using an adaptive Kalman filter (KF) framework. The accuracy of the algorithms is validated using (a) a database of 117 synthetic realistic phonations obtained using a sophisticated physiological model of speech production and (b) a database of 65 recordings of human phonations where the glottal cycles are calculated from electroglottograph signals. On average, the sawtooth waveform inspired pitch estimator and the nearly defect-free algorithms provided the best individual F(0) estimates, and the proposed KF approach resulted in a ∼16% improvement in accuracy over the best single F(0) estimation algorithm. These findings may be useful in speech signal processing applications where sustained vowels are used to assess vocal quality, when very accurate F(0) estimation is required.

Vocalization deficits in mice over-expressing alpha-synuclein, a model of pre-manifest Parkinson's disease.

Communication and swallowing deficits are common in Parkinson's disease (PD). Evidence indicates that voice and speech dysfunction manifest early, prior to motor deficits typically associated with striatal dopamine loss. Unlike deficits in the extremities, cranial sensorimotor deficits are refractory to standard dopamine-related pharmacological and surgical interventions, thus the mechanisms underlying vocal deficits are unclear. Although neurotoxin models have provided some insight, they typically model nigrostriatal dopamine depletion and are therefore limited. Widespread alpha-synuclein (aSyn) pathology is common to familial and sporadic PD, and transgenic mouse models based on aSyn overexpression present a unique opportunity to explore vocalization deficits in relation to extrastriatal, nondopaminergic pathologies. Specifically, mice overexpressing human wild-type aSyn under a broad neuronal promoter (Thy1-aSyn) present early, progressive motor and nonmotor deficits starting at 2-3 months, followed by parkinsonism with dopamine loss at 14 months. We recorded ultrasonic vocalizations from Thy1-aSyn mice and wild-type (WT) controls at 2-3, 6-7, and 9 months. Thy1-aSyn mice demonstrated early, progressive vocalization deficits compared with WT. Duration and intensity of calls were significantly reduced and call profile was altered in the Thy1-aSyn mice, particularly at 2-3 months. Call rate trended toward a more drastic decrease with age in the Thy1-aSyn mice compared with WT. Alpha-synuclein pathology is present in the periaqueductal gray and may underlie the manifestation of vocalization deficits. These results indicate that aSyn overexpression can induce vocalization deficits at an early age in mice and provides a new model for studying the mechanisms underlying cranial sensorimotor deficits and treatment interventions for PD.

Objective Automatic Assessment of Rehabilitative Speech Treatment in Parkinson's Disease.

Vocal performance degradation is a common symptom for the vast majority of Parkinson's disease (PD) subjects, who typically follow personalized one-to-one periodic rehabilitation meetings with speech experts over a long-term period. Recently, a novel computer program called Lee Silverman voice treatment (LSVT) Companion was developed to allow PD subjects to independently progress through a rehabilitative treatment session. This study is part of the assessment of the LSVT Companion, aiming to investigate the potential of using sustained vowel phonations towards objectively and automatically replicating the speech experts' assessments of PD subjects' voices as "acceptable" (a clinician would allow persisting during in-person rehabilitation treatment) or "unacceptable" (a clinician would not allow persisting during in-person rehabilitation treatment). We characterize each of the 156 sustained vowel /a/ phonations with 309 dysphonia measures, select a parsimonious subset using a robust feature selection algorithm, and automatically distinguish the two cohorts (acceptable versus unacceptable) with about 90% overall accuracy. Moreover, we illustrate the potential of the proposed methodology as a probabilistic decision support tool to speech experts to assess a phonation as "acceptable" or "unacceptable." We envisage the findings of this study being a first step towards improving the effectiveness of an automated rehabilitative speech assessment tool.

LSVT LOUD and LSVT BIG: Behavioral Treatment Programs for Speech and Body Movement in Parkinson Disease.

Recent advances in neuroscience have suggested that exercise-based behavioral treatments may improve function and possibly slow progression of motor symptoms in individuals with Parkinson disease (PD). The LSVT (Lee Silverman Voice Treatment) Programs for individuals with PD have been developed and researched over the past 20 years beginning with a focus on the speech motor system (LSVT LOUD) and more recently have been extended to address limb motor systems (LSVT BIG). The unique aspects of the LSVT Programs include the combination of (a) an exclusive target on increasing amplitude (loudness in the speech motor system; bigger movements in the limb motor system), (b) a focus on sensory recalibration to help patients recognize that movements with increased amplitude are within normal limits, even if they feel "too loud" or "too big," and (c) training self-cueing and attention to action to facilitate long-term maintenance of treatment outcomes. In addition, the intensive mode of delivery is consistent with principles that drive activity-dependent neuroplasticity and motor learning. The purpose of this paper is to provide an integrative discussion of the LSVT Programs including the rationale for their fundamentals, a summary of efficacy data, and a discussion of limitations and future directions for research.

Intensive voice treatment (LSVT LOUD) for children with spastic cerebral palsy and dysarthria.

PURPOSE: The purpose of this study was to examine the effects of an intensive voice treatment (Lee Silverman Voice Treatment, commonly known as LSVT LOUD) for children with spastic cerebral palsy (CP) and dysarthria. METHOD: A nonconcurrent multiple baseline single-subject design with replication across 5 children with spastic CP was used. Auditory-perceptual analysis of speech, acoustic measures of vocal functioning, and perceptual ratings by parents of participants were obtained at baseline, posttreatment, and 6-week follow-up recording sessions. RESULTS: Listeners consistently preferred the speech samples taken immediately posttreatment over those taken during the baseline phase for most perceptual characteristics rated in this study. Changes in acoustic measures of vocal functioning were not consistent across participants and occurred more frequently for maximum performance tasks as opposed to speech. Although parents of the treated participants reported an improved perception of vocal loudness immediately following treatment, maintenance of changes at 6-week follow-up varied across the participants. No changes were observed in the 5th participant, who did not receive treatment. CONCLUSIONS: These findings provide some preliminary observations that the children with spastic CP in this study not only tolerated intensive voice treatment but also showed improvement on select aspects of vocal functioning. These outcomes warrant further research through Phase 2 treatment studies.

Intensive voice treatment in Parkinson's disease: Lee Silverman Voice Treatment.

Advances in neuroscience have led to an expanded and improved understanding of neurobiological changes associated with rehabilitation and exercise in Parkinson's disease (PD). This knowledge has led to a direct clinical impact of increased referral for early and continuous exercise programs for individuals with PD (physical, occupational, speech therapy and general exercise programs) and an increased research focus on the impact of such approaches in humans with PD. The purpose of this article is to examine the role of speech therapy in the landscape of exercise-based interventions for individuals with PD. We will specifically focus on the intensive voice treatment protocol, Lee Silverman Voice Treatment, as an example therapy. This article will briefly review the literature on the characteristics and features of speech and voice disorders in individuals with PD, and will discuss the impact of pharmacological and surgical treatment techniques on these disorders. This will be followed by a focus on behavioral speech treatment, specifically Lee Silverman Voice Treatment, including development of the treatment approach, documenting efficacy, discovery of unexpected outcomes and insights into the mechanism of speech disorders in PD gained from treatment-related changes. This research will be placed in the context of other previous and current speech treatment approaches in development for individuals with PD, and will highlight future directions for research.

Formant centralization ratio: a proposal for a new acoustic measure of dysarthric speech.

PURPOSE: The vowel space area (VSA) has been used as an acoustic metric of dysarthric speech, but with varying degrees of success. In this study, the authors aimed to test an alternative metric to the VSA-the formant centralization ratio (FCR), which is hypothesized to more effectively differentiate dysarthric from healthy speech and register treatment effects. METHOD: Speech recordings of 38 individuals with idiopathic Parkinson's disease and dysarthria (19 of whom received 1 month of intensive speech therapy [Lee Silverman Voice Treatment; LSVT LOUD]) and 14 healthy control participants were acoustically analyzed. Vowels were extracted from short phrases. The same vowel-formant elements were used to construct the FCR, expressed as (F2u + F2a + F1i + F1u) / (F2i + F1a), the VSA, expressed as ABS([F1i x (F2a - F2u) + F1a x (F2u - F2i) + F1u x (F2i - F2a)] / 2), a logarithmically scaled version of the VSA (LnVSA), and the F2i /F2u ratio. RESULTS: Unlike the VSA and the LnVSA, the FCR and F2i/F2u ratio robustly differentiated dysarthric from healthy speech and were not gender sensitive. All metrics effectively registered treatment effects and were strongly correlated with each other. CONCLUSION: Albeit preliminary, the present findings indicate that the FCR is a sensitive, valid, and reliable acoustic metric for distinguishing dysarthric from unimpaired speech and for monitoring treatment effects, probably because of reduced sensitivity to interspeaker variability and enhanced sensitivity to vowel centralization.

Speech and swallowing disorders in Parkinson disease.

PURPOSE OF REVIEW: To review recent research and clinical studies pertaining to the nature, diagnosis, and treatment of speech and swallowing disorders in Parkinson disease. RECENT FINDINGS: Although some studies indicate improvement in voice and speech with dopamine therapy and deep brain stimulation of the subthalamic nucleus, others show minimal or adverse effects. Repetitive transcranial magnetic stimulation of the mouth motor cortex and injection of collagen in the vocal folds have preliminary data supporting improvement in phonation in people with Parkinson disease. Treatments focusing on vocal loudness, specifically LSVT LOUD (Lee Silverman Voice Treatment), have been effective for the treatment of speech disorders in Parkinson disease. Changes in brain activity due to LSVT LOUD provide preliminary evidence for neural plasticity. Computer-based technology makes the Lee Silverman Voice Treatment available to a large number of users. A rat model for studying neuropharmacologic effects on vocalization in Parkinson disease has been developed. New diagnostic methods of speech and swallowing are also available as the result of recent studies. SUMMARY: Speech rehabilitation with the LSVT LOUD is highly efficacious and scientifically tested. There is a need for more studies to improve understanding, diagnosis, prevention, and treatment of speech and swallowing disorders in Parkinson disease.

Speech treatment for Parkinson's disease.

Researchers estimate that 89% of people with Parkinson's disease (PD) have speech and voice disorders including disorders of laryngeal, respiratory and articulatory function. Despite the high incidence of speech and voice impairment, studies suggest that only 3-4% of people with PD receive speech treatment. Here, we review the literature on the characteristics and features of speech and voice disorders in people with PD and the types of treatment techniques available (medical, surgical and behavioral), with a focus on behavioral therapies. We provide a summary of the current status of the field of speech treatment in PD and recommendations for implementation of the current efficacy of treatment interventions. Directions for future research, including a speculative viewpoint on how the field will evolve in 5 years time, are discussed.