Aerobic Exercise May Up Brain-Training Benefits in Schizophrenia

Liam Davenport

July 29, 2020

Recent research has shown that social cognition training can benefit patients with schizophrenia, and a new study suggests that adding regular aerobic exercise sessions substantially increases the improvements in a dose-response manner.

In a randomized controlled trial (RCT) in 47 patients with schizophrenia, improvement in cognition tripled after adding an aerobic exercise program to cognitive training (CT) compared with CT alone.

Investigators, led by Keith H. Nuechterlein, PhD, professor of psychology, University of California, Los Angeles, note that there is "increasing evidence" to support the use of aerobic exercise to improve cognition and functioning in schizophrenia.

However, the "extent to which these gains are dependent on the amount of aerobic exercise completed remains unclear, although variability in adherence to intended exercise regiments is evident," they write.

They also point out that strategies to encourage regular exercise in patients with schizophrenia "are only starting to be explored."

The findings were scheduled to be presented at the Congress of the Schizophrenia International Research Society (SIRS) 2020, but the meeting was canceled because of the coronavirus pandemic.

Body Circuit Training

In the study, 47 patients with first-episode schizophrenia were randomly assigned to receive 6 months of CT alone or 6 months of CT plus exercise (CT+E).

All participants underwent 4 hours per week of computerized CT with BrainHQ and SocialVille programs (PositScience).

Patients in the CT+E group also took part in total body circuit training. Two aerobic exercise sessions per week were held at the clinic and two were to be completed at home. The goal was 150 minutes of exercise per week in total.

Exercise intensity was titrated to the individual, at a target of 60% to 80% of heart rate reserve.

Both the CT and CT+E groups showed cognitive gains on the MATRICS Consensus Cognitive Battery (MCCB) test, as well as work/school functioning gains on the Global Assessment Scale: Role.

However, results showed that the improvements in the CT+E group were three times greater than those shown in the CT group (P < .02 for the MCCB overall composite score).

Cognitive Gain Predictors

Because there were also substantial differences in the magnitude of cognitive improvement between the CT+E patients, the investigators sought to identify predictors of cognitive gain.

They found that patients in the CT+E group completed, on average, 85% of their in-clinic exercise sessions but only 39% of their home exercise sessions.

Those who completed a higher overall proportion of the exercise sessions had the largest cognitive gains (P = .03). This relationship was even stronger for patients who completed home exercise sessions (P = .02).

"Thus, aerobic exercise showed a dose-response relationship to cognitive improvement," the researchers report.

To improve completion rates for home sessions, the investigators tried paying the patients $5 for each session completed, which was "helpful" but did not iron out the variability in adherence.

They also tried assigning points for completing the most exercise sessions in the desired heart rate. They awarded a monthly winner and divided the patients into two completion groups. However, there were "mixed" results.

"Development of systematic incentive strategies to encourage regular aerobic exercise will be critical to successful dissemination of exercise programs as part of the treatment of schizophrenia," the researchers write.

They add that "pilot work with smartphone reminder systems is underway."

Effective, but Intensity Is Key

Commenting on the study for Medscape Medical News, David Kimhy, PhD, program leader for New Interventions in Schizophrenia, Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York City, said the results are consistent with previous research.  

Aerobic exercise is "highly effective in improving neurocognitive functioning" in patients with schizophrenia, said Kimhy, who was not involved in the research.

"Many individuals with schizophrenia tend to have a highly sedentary lifestyle resulting in poor aerobic fitness," he said. "Thus, aerobic fitness may represent one of the few modifiable risk factors for ameliorating poor neurocognitive functioning."

He noted that those benefits are in addition to "the many cardiovascular and health benefits aerobic exercise provide, which are nearly nonexistent for cognitive training and pharmacological interventions."

However, even if patients do take part in exercise sessions, "an important issue is in-session fidelity with training goals, as individuals may attend scheduled sessions but exercise very lightly," Kimhy noted.

He pointed out that the proportion of time these patients exercise at their designated target training intensity is highly correlated with neurocognitive improvement. Consequently, "exercising with a trainer may increase both attendance and in-session training fidelity."

Overall, although the current study suggests that in-clinic exercise sessions can be advantageous, "the recent COVID-19 pandemic made such options very challenging," Kimhy said.

"To address this issue, our research group and others are currently examining employment of aerobic exercise training at home, connected with trainers via live two-way telehealth video calls," he added.

Plasticity-Based Training

Two recent studies also indicate that remotely administered training programs can improve social cognition.

In the first study, published online July 2 in Schizophrenia Bulletin, 147 outpatients with schizophrenia were randomly assigned to complete 40 sessions of either SocialVille plasticity-based social cognition training or computer-based games such as crossword puzzles and solitaire.

"To develop these social cognition training exercises, we analyzed a tremendous amount of prior research about how the brain processes social information," lead author Mor Nahum, PhD, School of Occupational Therapy, Hebrew University, Jerusalem, Israel, said in a press release.

"It turns out that social cognition requires fast and accurate brain information processing, so we developed exercises that trained the brain to process social stimuli, like faces and emotions, quickly and accurately," Nahum added.

The interventions were conducted at home, with 55 participants completing the cognitive training and 53 completing the computer game sessions. (The remaining 39 either dropped out or withdrew.)

An average of 28 hours of social cognition training over 3 months was associated with a significant improvement on social cognitive composite scores compared with computer games (P < .001), but not on the UCSD Performance-Based Skills Assessment.

Further analysis suggested that more time spent on the cognitive training was associated with greater improvements in social cognition and social functioning, as well as on a motivation subscale.

The results "provide support for the efficacy of a remote, plasticity-based social cognitive training program," the investigators write.

Such programs "may serve as a cost-effective adjunct to existing psychosocial treatments," they add.

Auditory vs Visual Training

In the other study, published online May 21 in Schizophrenia Research, investigators led by Rogerio Panizzutti, MD, PhD, Instituto de Ciencias Biomedicas, Federal University of Rio de Janeiro, Brazil, randomly assigned 79 patients with schizophrenia to 40 hours of auditory or visual computerized training.

The exercises were dynamically equivalent between the two types of training, and their difficulty increased as the training progressed.

Both groups showed improvements in reasoning, problem-solving, and reported symptoms. However, the group receiving visual training also had greater improvement in global cognition and attention than the group receiving auditory training. 

All studies were supported by Posit Science Corporation. The study authors and Kimhy have disclosed no relevant financial relationships.

Congress of the Schizophrenia International Research Society (SIRS) 2020. Abstract O4.1.

Schizophr Bull. Published online May 21, 2020. Abstract

Schizophr Res. Published July 2, 2020. Abstract

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