Negative symptoms are a key feature of several psychiatric disorders. Difficulty identifying common neurobiological mechanisms that cut across diagnostic boundaries might result from equifinality (i.e., multiple mechanistic pathways to the same clinical profile), both within and across disorders. This study used a data-driven approach to identify unique subgroups of participants with distinct reward processing profiles to determine which profiles predicted negative symptoms.

Participants were a transdiagnostic sample of youth from a multisite study of psychosis risk, including 110 individuals at clinical high-risk for psychosis (CHR; meeting psychosis-risk syndrome criteria), 88 help-seeking participants who failed to meet CHR criteria and/or who presented with other psychiatric diagnoses, and a reference group of 66 healthy controls. Participants completed clinical interviews and behavioral tasks assessing four reward processing constructs indexed by the RDoC Positive Valence Systems: hedonic reactivity, reinforcement learning, value representation, and effort–cost computation.

k-means cluster analysis of clinical participants identified three subgroups with distinct reward processing profiles, primarily characterized by: a value representation deficit (54%), a generalized reward processing deficit (17%), and a hedonic reactivity deficit (29%). Clusters did not differ in rates of clinical group membership or psychiatric diagnoses. Elevated negative symptoms were only present in the generalized deficit cluster, which also displayed greater functional impairment and higher psychosis conversion probability scores.

Contrary to the equifinality hypothesis, results suggested one global reward processing deficit pathway to negative symptoms independent of diagnostic classification. Assessment of reward processing profiles may have utility for individualized clinical prediction and treatment.

People with post-traumatic stress disorder (PTSD) exhibit negative cognitions, predictive of PTSD severity. The Post-Traumatic Cognitions Inventory (PTCI) is a widely used instrument measuring trauma-related cognitions and beliefs with three subscales: negative thoughts of self (SELF), negative cognitions about the world (WORLD), and self-blame (BLAME).

The current study attempted to validate the use of the PTCI in people with serious mental illness (SMI), who have greater exposure to trauma and elevated rates of PTSD, using confirmatory factor analysis (CFA) and examining convergent and divergent correlations with relevant constructs.

Participants were 432 individuals with SMI and co-occurring PTSD diagnosis based on the Clinician Administered PTSD Scale, who completed PTCI and other clinical ratings.

CFAs provided adequate support for Foa’s three-factor model (SELF, WORLD, BLAME), and adequate support for Sexton’s four-factor model that also included a COPE subscale. Both models achieved measurement invariance at configural, metric and scalar levels for three diagnostic groups: schizophrenia, bipolar and major depression, as well as for ethnicity (White vs Black), and gender (male vs female). Validity of both models was supported by significant correlations between PTCI subscales, and self-reported and clinician assessed PTSD symptoms and associated symptoms.

Findings provide support for the psychometric properties of the PTCI and the conceptualization of Sexton’s four-factor and Foa’s three-factor models of PTCI among individuals diagnosed with SMI (Foa et al., 1999).

Schizophrenia is a disorder characterized by pervasive deficits in cognitive functioning. However, few well-powered studies have examined the degree to which cognitive performance is impaired even among individuals with schizophrenia not currently on antipsychotic medications using a wide range of cognitive and reinforcement learning measures derived from cognitive neuroscience. Such research is particularly needed in the domain of reinforcement learning, given the central role of dopamine in reinforcement learning, and the potential impact of antipsychotic medications on dopamine function.

The present study sought to fill this gap by examining healthy controls (N = 75), unmedicated (N = 48) and medicated (N = 148) individuals with schizophrenia. Participants were recruited across five sites as part of the CNTRaCS Consortium to complete tasks assessing processing speed, cognitive control, working memory, verbal learning, relational encoding and retrieval, visual integration and reinforcement learning.

Individuals with schizophrenia who were not taking antipsychotic medications, as well as those taking antipsychotic medications, showed pervasive deficits across cognitive domains including reinforcement learning, processing speed, cognitive control, working memory, verbal learning and relational encoding and retrieval. Further, we found that chlorpromazine equivalency rates were significantly related to processing speed and working memory, while there were no significant relationships between anticholinergic load and performance on other tasks.

These findings add to a body of literature suggesting that cognitive deficits are an enduring aspect of schizophrenia, present in those off antipsychotic medications as well as those taking antipsychotic medications.

Neurocognitive deficits are often seen as core features of schizophrenia, and as primary determinants of poor functioning. Yet, our clinical observations suggest that individuals who score within the impaired range on standardized tests can reliably perform better in complex real-world situations, especially when performance is embedded within a positive socio-affective context.

We analyzed literature on the influence of non-neurocognitive factors on test performance in order to clarify their contributions.

We identified seven non-neurocognitive factors that significantly contribute to neurocognitive test performance: avolition, dysfunctional attitudes, effort, stress, negative emotions, asociality, and disorganized symptoms. We then proposed an alternative model based on dysfunctional (e.g. defeatist) attitudes and their consequences for motivation and sustained task engagement. We demonstrated that these factors account for substantial variance in negative symptoms, neurocognitive test performance, and functional outcomes. We then demonstrated that recovery-oriented cognitive therapy – which is derived from this alternative model and primarily targets dysfunctional beliefs – has been successful in the treatment of low functioning individuals with schizophrenia.

The contributions of neurocognitive impairments to poor real-world functioning in people with schizophrenia may be overstated in the literature, and may even be limited relative to non-neurocognitive factors. We offer suggestions for further research to more precisely quantify the contributions of attitudinal/motivation v. neurocognitive factors in schizophrenia.

Prior optical coherence tomography (OCT) studies of schizophrenia have identified thinning of retinal layers. However, findings have varied across reports, and most studies have had serious methodological limitations. To address unresolved issues, we determined whether: (1) retinal thinning in schizophrenia occurs independently of comorbid medical conditions that affect the retina; (2) thinning is independent of antipsychotic medication dose; (3) optic nerve parameters are abnormal in schizophrenia; and (4) OCT indices are related to visual and cognitive impairments common in schizophrenia.

A total of 32 people with schizophrenia and 32 matched controls participated. Spectral domain OCT generated data on retinal nerve fiber layer (RNFL), macula, and ganglion cell-inner plexiform layer (GCL-IPL) thickness, in addition to cup volume and the cup-to-disc ratio at the optic nerve head. Subjects with schizophrenia also completed measures of symptoms, visual processing, and IQ.

The groups did not differ on RNFL, macula, or GCL-IPL thickness. However, thinning of these layers was related to the presence of diabetes or hypertension across the sample as a whole. The schizophrenia group demonstrated enlarged cup volume and an enlarged cup-to-disc ratio in both eyes, which were unrelated to medical comorbidity, but were related to increased cognitive symptoms.

Past reports of retinal thinning may be artifacts of medical comorbidity that is over-represented in schizophrenia, or other confounds. However, optic nerve head abnormalities may hold promise as biomarkers of central nervous system abnormality, including cognitive decline, in schizophrenia.

A cognitive–behavioural therapy (CBT) programme designed for post-traumatic stress disorder (PTSD) in people with severe mental illness, including breathing retraining, education and cognitive restructuring, was shown to be more effective than usual services.

To evaluate the incremental benefit of adding cognitive restructuring to the breathing retraining and education components of the CBT programme (trial registration: clinicaltrials.gov identifier: NCT00494650).

In all, 201 people with severe mental illness and PTSD were randomised to 12- to 16-session CBT or a 3-session brief treatment programme (breathing retraining and education). The primary outcome was PTSD symptom severity. Secondary outcomes were PTSD diagnosis, other symptoms, functioning and quality of life.

There was greater improvement in PTSD symptoms and functioning in the CBT group than in the brief treatment group, with both groups improving on other outcomes and effects maintained 1-year post-treatment.

Cognitive restructuring has a significant impact beyond breathing retraining and education in the CBT programme, reducing PTSD symptoms and improving functioning in people with severe mental illness.