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Moderate effects of noninvasive brain stimulation of the frontal cortex for improving negative symptoms in schizophrenia
- Source :
- Neuroscience & Biobehavioral Reviews. 89:111-118
- Publication Year :
- 2018
-
Abstract
- Background Negative symptoms in schizophrenia concern a clinically relevant reduction of goal-directed behavior that strongly and negatively impacts daily functioning. Existing treatments are of marginal effect and novel approaches are needed. Noninvasive neurostimulation by means of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are novel approaches that may hold promise. Objectives To provide a quantitative integration of the published evidence regarding effects of rTMS and tDCS over the frontal cortex on negative symptoms, including an analysis of effects of sham stimulation. Methods Meta-analysis was applied, using a random effects model, to calculate mean weighted effect sizes (Cohen's d). Heterogeneity was assessed by using Cochrans Q and I2 tests. Results For rTMS treatment, the mean weighted effect size compared to sham stimulation was 0.64 (0.32–0.96; k = 22, total N = 827). Studies with younger participants showed stronger effects as compared to studies with older participants. For tDCS studies a mean weighted effect size of 0.50 (−0.07 to 1.07; k = 5, total N = 134) was found. For all frontal noninvasive neurostimulation studies together (i.e., TMS and tDCS studies combined) active stimulation was superior to sham, the mean weighted effect size was 0.61 (24 studies, 27 comparisons, 95% confidence interval 0.33–0.89; total N = 961). Sham rTMS (baseline - posttreatment comparison) showed a significant improvement of negative symptoms, d = 0.31 (0.09–0.52; k = 16, total N = 333). Whereas previous meta-analyses were underpowered, our meta-analysis had a power of 0.87 to detect a small effect. Conclusions The available evidence indicates that noninvasive prefrontal neurostimulation can improve negative symptoms. This finding suggests a causal role for the lateral frontal cortex in self-initiated goal-directed behavior. The evidence is stronger for rTMS than for tDCS, although this may be due to the small number of studies as yet with tDCS. More research is needed to establish moderator variables that may affect response to neurostimulation and to optimize treatment parameters in order to achieve stable and durable (and thus clinically relevant) effects.
- Subjects :
- medicine.medical_specialty
TRANSCRANIAL MAGNETIC STIMULATION
Cognitive Neuroscience
medicine.medical_treatment
Hypofrontality
RTMS
PREFRONTAL CORTEX
Frontal cortex
TDCS
03 medical and health sciences
Behavioral Neuroscience
DOUBLE-BLIND
0302 clinical medicine
Physical medicine and rehabilitation
medicine
Prefrontal cortex
Neurostimulation
THETA BURST STIMULATION
Transcranial direct-current stimulation
business.industry
RANDOMIZED CONTROLLED-TRIAL
1ST EPISODE SCHIZOPHRENIA
medicine.disease
Frontal Lobe
030227 psychiatry
Transcranial magnetic stimulation
Treatment Outcome
Neuropsychology and Physiological Psychology
Schizophrenia
Brain stimulation
Meta-analysis
Transcranial direct current stimulation
Negative symptoms
HYPOFRONTALITY
business
HALLUCINATIONS
030217 neurology & neurosurgery
Subjects
Details
- Language :
- English
- ISSN :
- 01497634
- Volume :
- 89
- Database :
- OpenAIRE
- Journal :
- Neuroscience & Biobehavioral Reviews
- Accession number :
- edsair.doi.dedup.....f75c808ddd024eec33d5b0f5c7d032ed