This article analyzes the mechanisms of harm-avoidance learning as a potential model for obsessive-compulsive disorder.
This Editorial discusses the effectiveness of short-term psychodynamic psychotherapy for major depressive disorder.
Recent work suggests that the amphetamine sensitization model of schizophrenia can safely be induced in healthy volunteers and is associated both with behavioral and dopaminergic hypersensitivity to amphetamine. However, the effects of a sensitization on brain function remain unclear.
To assess the impact of a sensitizing dosage regimen of dextroamphetamine on human cortical functioning and cognition.
Randomized, double-blind, parallel-groups design using pharmacological functional magnetic resonance imaging.
The neuroimaging research unit at the Institute of Psychiatry, King's College London, London, England.
Healthy male volunteers (n = 22).
Dextroamphetamine (20 mg) or placebo administration at 4 testing sessions, using a dosage regimen shown to induce sensitization (ie, 3 doses administered with a 48-hour interdose interval and a final dose after a 2-week washout period).
Sensitization was characterized by enhanced subjective response to the drug, changes in behavioral performance (reaction time and accuracy), and functional magnetic resonance imaging measurements of brain activity during an N-back working memory task.
Sensitization was associated with more rapid responding during the performance of an intermediate-load working memory challenge. During a high-load cognitive challenge, sensitization did not produce performance deficits, but functional magnetic resonance imaging showed hyperactivity of the dorsolateral prefrontal cortex and aberrant recruitment of the superior temporal gyrus, caudate nucleus, and thalamus. Furthermore, the change in striatal activity was negatively correlated with the enhanced subjective effects of the drug, whereas prefrontal hyperactivity was positively correlated with sensitized measures of alertness.
These transient load-dependent abnormalities of frontal and temporal activity induced by amphetamine sensitization support neuroimaging findings in schizophrenic patients, implying that amphetamine sensitization may help to bridge pathophysiological theories of schizophrenia that focus on pharmacological (dopaminergic) and cognitive mechanisms, respectively.
Hauser et al determine the impaired decision-making and learning mechanisms in adolescents with attention-deficit/hyperactivity disorder using advanced computational models, as well as the related neural reward prediction error processes using multimodal neuroimaging.
This cross-sectional study compares white matter myelination and microstructure in individuals with vs without psychotic experiences and examines neurodevelopmental variables associated with the experiences.
This meta-analysis of trials comparing collaborative to usual care in adults with depression uses individual participant data to investigate if chronic comorbidities modify the effects of the intervention.
This randomized clinical trial evaluates the safety and efficacy of basimglurant modified-release vs placebo as adjunctive therapy to ongoing antidepressant medication therapy in patients with major depressive disorder who had inadequate response within the current episode.
This study identifies a potential systems-level intermediate phenotype linked to emotion processing in schizophrenia and examines the psychological association, task specificity, test-retest reliability, and clinical validity of the identified phenotype.
This longitudinal cohort study uses data from the National Medicaid Analytic Extract and the National Center for Health Statistics to assess the postdischarge risk for suicide among psychiatric inpatients.
This pharmacoepidemiology study examines associations between first-trimester antipsychotic exposure and risk for overall congenital and cardiac malformations among children born to women enrolled in Medicaid.
This twin study uses structural equation modeling to examine whether white matter integrity is associated with the genetic liability for developing schizophrenia.