Brain Structures and Cognitive Decline: Moderation Analysis of the PACt-MD Randomized Clinical Trial of Brain Stimulation Plus Cognitive Remediation in Older Adults With Remitted Depression or Mild Cognitive Impairment.

OBJECTIVE

To identify which patients with remitted major depressive disorder (rMDD) or mild cognitive impairment (MCI) benefit from cognitive remediation (CR) plus transcranial direct current stimulation (tDCS).

DESIGN

We conducted a moderator analysis to examine the effects of baseline brain magnetic resonance imaging (MRI) measures on the impact of CR + tDCS on cognitive decline in Prevention of Alzheimer's dementia with CR plus tDCS in MCI and Depression (PACt-MD), a double-masked randomized two-arm controlled trial with assessments at baseline, two months, and yearly for three to seven years.

SETTING

Five academic hospitals in Toronto, Canada.

PARTICIPANTS

A total of 246 participants with rMDD, MCI, or both, with an analyzable baseline MRI.

INTERVENTION: CR + tDCS or sham CR + sham tDCS.

MEASUREMENTS: Overall cortical thickness, overall fractional anisotropy, and cortical thickness in an a-priori composite region of interest (ROI); changes in global cognition, executive function, or verbal memory.

RESULTS

Overall cortical thickness moderated decline in global cognition (Χ² = 10.43, df = 3, p = 0.015); ROI cortical thickness moderated treatment-related changes in global cognition (Χ² = 29.05, df = 3, p <0.001), executive function (Χ² = 11.57, df = 3, p = 0.009), and verbal memory (Χ² = 16.08, df = 3, p = 0.001).

CONCLUSION

Future work needs to confirm that cortical thickness can be used to select adults at risk for dementia who are the most likely to benefit from CR + tDCS. CLINCIALTRIALS.

GOV IDENTIFIER: NCT02386670.