Concurrent cognitive control training augments the antidepressant efficacy of tDCS: a pilot study.
BACKGROUND
Major depressive disorder (MDD) is frequently associated with underactivity of the dorsolateral prefrontal cortex (DLPFC) which has led to this brain region being identified as an important target for the development of neurobiological treatments. Transcranial direct current stimulation (tDCS) administered to the DLPFC has antidepressant efficacy, however the magnitude of antidepressant outcomes are limited. Concurrent cognitive activity has been shown to enhance tDCS induced stimulation effects. Cognitive control training (CCT) is a new cognitive therapy for MDD that aims to enhance DLPFC activity via behavioral methods.


OBJECTIVE
We tested the hypothesis that co-administration of DLPFC tDCS and CCT would result in a greater reduction in depressive symptomology than administration of tDCS or CCT alone.


METHODS
27 adult participants with MDD were randomized into a three-arm sham-controlled between-groups pilot study comparing the efficacy of 2 mA tDCS + CCT, sham tDCS + CCT and sham CCT + 2 mA tDCS (5 sessions administered on consecutive working days). Blinded assessments of depression severity and cognitive control were conducted at baseline, end of treatment and a three week follow up review.


RESULTS
All three treatment conditions were associated with a reduction in depression severity at the end of five treatment sessions. However, only administration of tDCS + CCT resulted in sustained antidepressant response at follow up, the magnitude of which was greater than that observed immediately following conclusion of the treatment course.


CONCLUSIONS
The results provide preliminary evidence that concurrent CCT enhances antidepressant outcomes from tDCS. In the current sample, participants receiving concurrent tDCS and CCT continued to improve following cessation of treatment. The clinical superiority of a combined therapeutic approach was apparent even in a small sample and following a relatively short treatment course.
Monash University, Central Clinical School, Monash Alfred Psychiatry Research Centre, Level 4, 607 St Kilda Rd., Prahran, VIC 3004, Australia. Electronic address: rebecca.segrave@monash.edu.
R A
RA
Segrave
Monash University, Central Clinical School, Monash Alfred Psychiatry Research Centre, Level 4, 607 St Kilda Rd., Prahran, VIC 3004, Australia.
S
S
Arnold
Monash University, Central Clinical School, Monash Alfred Psychiatry Research Centre, Level 4, 607 St Kilda Rd., Prahran, VIC 3004, Australia.
K
K
Hoy
Monash University, Central Clinical School, Monash Alfred Psychiatry Research Centre, Level 4, 607 St Kilda Rd., Prahran, VIC 3004, Australia.
P B
PB
Fitzgerald
D000328:Adult; D003071:Cognition / Q000502:physiology; D015928:Cognitive Behavioral Therapy; D003131:Combined Modality Therapy; D003865:Major Depressive Disorder / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D017397:Prefrontal Cortex / Q000503:physiopathology*; D065908:Transcranial Direct Current Stimulation; D016896:Treatment Outcome; D055815:Young Adult
Cognitive control; Cognitive training; Depression; Dorsolateral prefrontal cortex; Transcranial direct current stimulation