Pharmacologic Augmentation of Targeted Cognitive Training in Schizophrenia

Overview

These studies look to conduct efficient pilot testing of a novel intervention strategy for chronic psychotic disorders - Pharmacologic Augmentation of Cognitive Therapy (PACT) - via an experimental medicine approach. Antipsychotics are the major therapeutic tool for chronic psychotic disorders, including schizophrenia, but do not significantly alter their course or real-life impact. Specific cognitive therapies achieve modest symptom reduction and improved function and cognition in psychosis patients, including "bottom-up" sensory-based targeted cognitive training (TCT). While benefits of TCT are evident at the group level, almost half of all patients demonstrate little or no cognitive gains after 30-40 hours (h) of TCT. For patients and clinicians, the costs and logistical complexities associated with these time- and resource-intensive interventions can be prohibitive. We propose and will test a novel "augmentation strategy" for using medications to specifically enhance the benefits of TCT in schizophrenia.

Subjects who meet criteria for study entry come to UCSD where consenting and a comprehensive screening and diagnostic assessment including a Mini-International Neuropsychiatric Interview are conducted. After initial screening, subjects return twice, approximately 7 days apart, for biomarker assessment after challenge with placebo (PBO) (Test 1) or amphetamine 5 mg po (AMPH) (Test 2). Subjects then enter the "treatment phase", completing up to 30 one-hour targeted cognitive training (TCT) sessions. Subjects are randomized to one of 2 groups: "AMPH Group" receive AMPH (5 mg po) 1h before each TCT session; "PBO Group" receive PBO dosed identically to AMPH. Pill identity (AMPH vs. PBO) is blind to subjects and staff. TCT sessions are scheduled approximately 3 times each week for 10 weeks. TCT consists of 7 computerized exercises delivered on standardized laptops and headphones. Collectively, these exercises target learning mechanisms involving auditory perception and processing speed (Sound Sweeps, Fine Tuning) and auditory memory (Syllable Stacks, Memory Grid, To-Do List Training, Rhythm Recall, Hear-Hear). Training is structured into blocks that deliver stimulus sets with varying temporal and psychophysical parameters to allow continuous learning and improvement. Blocks consist of 10-35 adaptive trials where the subject's progression depends on their performance. Exercises apply an n-up/m-down algorithm to responses to estimate psychophysical thresholds while ensuring that participants remain engaged and challenged at an appropriate level (\~80% accuracy) as their abilities improve. Clinical and functional outcome measures are acquired at "baseline", and 1-2 days after completion of 10, 20 and 30 TCT sessions and 12 weeks post-training. Urine toxicology screens and Columbia Suicide Severity Rating Scales are performed at least weekly, prior to a TCT session. A treatment satisfaction scale (100 mm line) rates expectations at the start of the study and actual experience of treatment in three areas: "satisfaction", "hard work" and "worthwhile." Subjects from both groups return to UCSD 12 weeks after the TCT has ended, and outcome measures are reassessed to test the "durability" of benefits.