Response to targeted cognitive training may be neuroprotective in patients with early schizophrenia

Harnessing neuroplasticity

Twenty years ago, cognitive impairments were recognized as an unmet treatment need in schizophrenia. Basic science discoveries in neuroplasticity had led to cognitive training approaches for dyslexia. We wondered whether a similar approach could target working memory deficits in schizophrenia by harnessing plasticity in the auditory cortex. Our per protocol experimental therapeutics studies tested the hypothesis that sharpening auditory cortical representations would result in better verbal learning and memory. We also later studied the effects of intensive training of basic social cognitive operations. Our training protocols were deliberately focused, effortful and intensive, since participants were often up against decades of cortical dysplasticity. In studies in different stages of illness, we demonstrated that neuroscience-informed cognitive training was associated with: (1) proximal psychophysical as well as distal cognitive improvements; (2) increases in serum BDNF levels; (3) negative effects of serum anticholinergic burden; (4) electrophysiologic responses and brain activation patterns consistent with restorative neuroplastic changes in cortex; (5) positive cortical and thalamic volumetric changes suggestive of neuroprotection; (6) better 6-month clinical functioning in those with a positive initial response. Taken together, this work indicates how much the field of psychiatry could benefit from a deep understanding of the basic science of cortical neuroplasticity processes and of how they can be deliberately and efficiently harnessed for therapeutic purposes.

The Effects of Remote Cognitive Training Combined With a Mobile App Intervention on Psychosis: Double-Blind Randomized Controlled Trial

BACKGROUND

Impairments in cognition and motivation are core features of psychosis and strong predictors of social and occupational functioning. Accumulating evidence indicates that cognitive deficits in psychosis can be improved by computer-based cognitive training programs; however, barriers include access and adherence to cognitive training exercises. Limited evidence-based methods have been established to enhance motivated behavior. In this study, we tested the effects of web-based targeted cognitive and social cognitive training (TCT) delivered in conjunction with an innovative digital smartphone app called Personalized Real-Time Intervention for Motivational Enhancement (PRIME). The PRIME app provides users with a motivational coach to set personalized goals and secure social networking for peer support.

OBJECTIVE

This study investigated whether deficits in cognition and motivation in people with a psychosis spectrum disorder (N=100) can be successfully addressed with 30 hours of TCT+PRIME as compared with 30 hours of a computer games control condition (CG) plus PRIME (CG+PRIME). Here, we describe our study procedures, the feasibility and acceptability of the intervention, and the results on all primary outcomes.

METHODS

In this double-blind randomized controlled trial, English-speaking participants completed all cognitive training, PRIME activities, and assessments remotely. Participants completed a diagnostic interview and remote cognitive, clinical, and self-report measures at baseline, posttraining, and at a 6-month follow-up.

RESULTS

This study included participants from 27 states across the United States and 8 countries worldwide. The study population was 58% (58/100) female, with a mean age of 33.77 (SD 10.70) years. On average, participants completed more than half of the cognitive training regimen (mean 18.58, SD 12.47 hours of training), and logged into the PRIME app 4.71 (SD 1.58) times per week. The attrition rate of 22% (22/100) was lower than that reported in our previous studies on remote cognitive training. The total sample showed significant gains in global cognition (P=.03) and attention (P<.001). The TCT+PRIME participants showed significantly greater gains in emotion recognition (P<.001) and global cognition at the trend level (P=.09), although this was not statistically significant, relative to the CG+PRIME participants. The total sample also showed significant improvements on multiple indices of motivation (P=.02-0.05), in depression (P=.04), in positive symptoms (P=.04), and in negative symptoms at a trend level (P=.09), although this was not statistically significant. Satisfaction with the PRIME app was rated at 7.74 (SD 2.05) on a scale of 1 to 10, with higher values indicating more satisfaction.

CONCLUSIONS

These results demonstrate the feasibility and acceptability of remote cognitive training combined with the PRIME app and that this intervention can improve cognition, motivation, and symptoms in individuals with psychosis. TCT+PRIME appeared more effective in improving emotion recognition and global cognition than CG+PRIME. Future analyses will test the relationship between hours of cognitive training completed; PRIME use; and changes in cognition, motivation, symptoms, and functioning.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02782442; https://clinicaltrials.gov/study/NCT02782442.

Efficacy of Remotely Delivered Evidence-Based Psychosocial Treatments for Schizophrenia-Spectrum Disorders: A Series of Systematic Reviews and Meta-Analyses

BACKGROUND

Schizophrenia is among the most persistent and debilitating mental health conditions worldwide. The American Psychological Association (APA) has identified 10 psychosocial treatments with evidence for treating schizophrenia and these treatments are typically provided in person. However, in-person services can be challenging to access for people living in remote geographic locations. Remote treatment delivery is an important option to increase access to services; however, it is unclear whether evidence-based treatments for schizophrenia are similarly effective when delivered remotely.

STUDY DESIGN

The current study consists of a series of systematic reviews and meta-analyses examining the evidence-base for remote-delivery of each of the 10 APA evidence-based treatments for schizophrenia.

RESULTS

Of the 10 treatments examined, only cognitive remediation (CR), cognitive-behavioral therapy (CBT), and family psychoeducation had more than 2 studies examining their efficacy for remote delivery. Remote delivery of CBT produced moderate effects on symptoms (g = 0.43) and small effects on functioning (g = 0.26). Remote delivery of CR produced small-moderate effects on neurocognition (g = 0.35) and small effects on functioning (g = 0.21). There were insufficient studies of family psychoeducation with equivalent outcome measures to assess quantitatively, however, studies of remotely delivered family psychoeducation suggested that it is feasible, acceptable, and potentially effective.

CONCLUSIONS

Overall, the evidence-base for remotely delivered treatment for schizophrenia is limited. Studies to date suggest that remote adaptations may be effective; however, more rigorous trials are needed to assess efficacy and methods of remote delivery that are most effective.

Accelerated cortical thinning precedes and predicts conversion to psychosis: The NAPLS3 longitudinal study of youth at clinical high-risk

Progressive grey matter loss has been demonstrated among clinical high-risk (CHR) individuals who convert to psychosis, but it is unknown whether these changes occur prior to psychosis onset. Identifying illness-related neurobiological mechanisms that occur prior to conversion is essential for targeted early intervention. Among participants in the third wave of the North American Prodrome Longitudinal Study (NAPLS3), this report investigated if steeper cortical thinning was observable prior to psychosis onset among CHR individuals who ultimately converted (CHR-C) and assessed the shortest possible time interval in which rates of cortical thinning differ between CHR-C, CHR non-converters (CHR-NC), and health controls (HC). 338 CHR-NC, 42 CHR-C, and 62 HC participants (age 19.3±4.2, 44.8% female, 52.5% racial/ethnic minority) completed up to 5 MRI scans across 8 months. Accelerated thinning among CHR-C compared to CHR-NC and HC was observed in multiple prefrontal, temporal, and parietal cortical regions. CHR-NC also exhibited accelerated cortical thinning compared to HC in several of these areas. Greater percent decrease in cortical thickness was observed among CHR-C compared to other groups across 2.9±1.8 months, on average, in several cortical areas. ROC analyses discriminating CHR-C from CHR-NC by percent thickness change in a left hemisphere region of interest, scanner, age, age2, and sex had an AUC of 0.74, with model predictive power driven primarily by percent thickness change. Findings indicate that accelerated cortical thinning precedes psychosis onset and differentiates CHR-C from CHR-NC and HC across short time intervals. Mechanisms underlying cortical thinning may provide novel treatment targets prior to psychosis onset.

Editorial: New Clues Into Cortical Changes That Converge on Psychosis

Adults living with schizophrenia have prominent and widespread alterations in brain structure and function, but until recently little was known about the developmental timing and course of such changes. Prospective studies of individuals at elevated risk for developing psychosis, termed clinical high-risk (CHR) or psychosis risk syndrome patients, can address these questions, thus providing clues into neurobiological mechanisms that occur prior to illness onset. In this issue, Fortea et al.¹ present the results of a prospective longitudinal brain imaging investigation of 107 adolescents at CHR for developing a psychotic disorder (23% of whom developed psychosis over the follow-up period) and 102 typically developing controls. Participants were scanned at baseline and at 18-month follow-up or at the time of conversion to psychosis. Using linear mixed-effects models to measure cortical surface area over time, the authors found that youth who developed a psychotic disorder during the follow-up period experienced greater loss of cortical surface area in bilateral parietal and right frontal regions compared to CHR youth who did not develop psychosis, and in left parietal and occipital regions compared to healthy controls. Findings were not accounted for by antipsychotic medication use, cannabis use, or general intelligence. Thus, these observations suggest that emerging psychosis may have an impact on typical neuromaturational changes that occur during adolescence.

Synaptic plasticity and mental health: methods, challenges and opportunities

Activity-dependent synaptic plasticity is a ubiquitous property of the nervous system that allows neurons to communicate and change their connections as a function of past experiences. Through reweighting of synaptic strengths, the nervous system can remodel itself, giving rise to durable memories that create the biological basis for mental function. In healthy individuals, synaptic plasticity undergoes characteristic developmental and aging trajectories. Dysfunctional plasticity, in turn, underlies a wide spectrum of neuropsychiatric disorders including depression, schizophrenia, addiction, and posttraumatic stress disorder. From a mechanistic standpoint, synaptic plasticity spans the gamut of spatial and temporal scales, from microseconds to the lifespan, from microns to the entire nervous system. With the numbers and strengths of synapses changing on such wide scales, there is an important need to develop measurement techniques with complimentary sensitivities and a growing number of approaches are now being harnessed for this purpose. Through hemodynamic measures, structural and tracer imaging, and noninvasive neuromodulation, it is possible to image structural and functional changes that underlie synaptic plasticity and associated behavioral learning. Here we review the mechanisms of neural plasticity and the historical and future trends in techniques that allow imaging of synaptic changes that accompany psychiatric disorders, highlighting emerging therapeutics and the challenges and opportunities accompanying this burgeoning area of study.

Can neuroimaging-based biomarkers predict response to cognitive remediation in patients with psychosis? A state-of-the-art review

BACKGROUND

Cognitive Remediation (CR) is designed to halt the pathological neural systems that characterize major psychotic disorders (MPD), and its main objective is to improve cognitive functioning. The magnitude of CR-induced cognitive gains greatly varies across patients with MPD, with up to 40% of patients not showing gains in global cognitive performance. This is likely due to the high degree of heterogeneity in neural activation patterns underlying cognitive endophenotypes, and to inter-individual differences in neuroplastic potential, cortical organization and interaction between brain systems in response to learning. Here, we review studies that used neuroimaging to investigate which biomarkers could potentially serve as predictors of treatment response to CR in MPD.

METHODS

This systematic review followed the PRISMA guidelines. An electronic database search (Embase, Elsevier; Scopus, PsycINFO, APA; PubMed, APA) was conducted in March 2021. peer-reviewed, English-language studies were included if they reported data for adults aged 18+ with MPD, reported findings from randomized controlled trials or single-arm trials of CR; and presented neuroimaging data.

RESULTS

Sixteen studies were included and eight neuroimaging-based biomarkers were identified. Auditory mismatch negativity (3 studies), auditory steady-state response (1), gray matter morphology (3), white matter microstructure (1), and task-based fMRI (7) can predict response to CR. Efference copy corollary/discharge, resting state, and thalamo-cortical connectivity (1) require further research prior to being implemented.

CONCLUSIONS

Translational research on neuroimaging-based biomarkers can help elucidate the mechanisms by which CR influences the brain's functional architecture, better characterize psychotic subpopulations, and ultimately deliver CR that is optimized and personalized.

Evaluation of the frequency following response as a predictive biomarker of response to cognitive training in schizophrenia

Neurophysiological biomarkers of auditory processing show promise predicting outcomes following auditory-based targeted cognitive training (TCT) in schizophrenia, but the viability of the frequency following response (FFR) as a biomarker has yet to be examined, despite its ecological and face validity for auditory-based interventions. FFR is an event-related potential (ERP) that reflects early auditory processing. We predicted that schizophrenia patients would show acute- and longer-term FFR malleability in the context of TCT. Patients were randomized to either TCT (n = 30) or treatment as usual (TAU; n = 22), and electroencephalography was recorded during rapid presentation of an auditory speech stimulus before treatment, after one hour of training, and after 30 h of training. Whereas patients in the TCT group did not show changes in FFR after training, amplitude reductions were observed in the TAU. FFR was positively associated with performance on a measure of single word-in-noise perception in the TCT group, and with a measure of sentence-in-noise perception in both groups. Psychometric reliability analyses of FFR scores indicated high internal consistency but low one-hour and 12-week test-rest reliability. These findings support the dissociation between measures of speech discriminability along the hierarchy of cortical and subcortical early auditory information processing in schizophrenia.

Durable Cognitive Gains and Symptom Improvement Are Observed in Individuals With Recent-Onset Schizophrenia 6 Months After a Randomized Trial of Auditory Training Completed Remotely

OBJECTIVE

Cognitive impairment in schizophrenia predicts functional outcomes and is largely unresponsive to pharmacology or psychotherapy; it is thus a critical unmet treatment need. This article presents the impact of remotely completed, intensive, targeted auditory training (AT) vs control condition computer games (CG) in a double-blind randomized trial in young adults with recent-onset schizophrenia.

METHOD

Participants (N = 147) were assessed for cognition, symptoms, and functioning at baseline, post-intervention, and at 6-month follow-up. All participants were provided with laptop computers and were instructed to complete 40 hours remotely of training or computer games. An intent-to-treat analysis (N = 145) was performed using linear mixed models with time modeled as a continuous variable. Planned contrasts tested the change from baseline to post-training, baseline to 6-month follow-up, and post-training to 6-month follow-up.

RESULTS

Global Cognition, which had improved in the AT group relative to the CG group at post-training, showed durable gains at 6-month follow-up in an omnibus group-by-time interaction test (F(1,179) = 4.80, P = .030), as did Problem-Solving (F(1,179) = 5.13, P = .025), and Speed of Processing improved at trend level significance (F(1,170) = 3.80, P = .053). Furthermore, the AT group showed significantly greater improvement than the CG group in positive symptoms (F(1,179) = 4.06, P = .045).

CONCLUSIONS

These results provide the first evidence of durable cognitive gains and symptom improvement at follow-up of cognitive training (CT) in early schizophrenia completed independently and remotely. While functioning did not show significant improvement, these findings suggest that intensive targeted CT of auditory processing is a promising component of early intervention to promote recovery from psychosis.