Effects of D-cycloserine administration on weekly nonemotional memory tasks in healthy participants.
BACKGROUND
The application of weekly doses of D-cycloserine (DCS) to the enhancement of exposure-based treatments has been a particular achievement of translational research. It is not known, however, whether this enhancement effect can be extended to other forms of learning. In this study, we investigated the relative benefit of DCS versus placebo for enhancing nonemotional verbal and nonverbal memory across weekly trials.


METHODS
We randomized healthy participants to weekly doses of 50 mg DCS or placebo, with 33 participants completing a 5-week protocol. Participants completed baseline neuropsychological evaluation and then 4 subsequent weeks of repeated learning tasks.


RESULTS
No improvement was found in immediate or delayed memory following single doses of DCS for the memory tasks repeated on a weekly basis. Trends for an advantage of DCS were evident for novel word lists given each week.


CONCLUSIONS
The learning tasks in our study were particularly distinct from the extinction learning paradigms that have shown strong DCS effects, and we were unable to demonstrate useful DCS effects with these nonemotional stimuli. Additional research is needed to elucidate the bounds of DCS augmentation effects on therapeutic learning.
Otto
Michael W
MW
Boston University, Harvard Medical School, Boston, MA 02215, USA. mwotto@bu.edu
Basden
Shawnee L
SL
McHugh
R Kathryn
RK
Kantak
Kathleen M
KM
Deckersbach
Thilo
T
Cather
Corinne
C
Goff
Donald C
DC
Hofmann
Stefan G
SG
Berry
Angela C
AC
Smits
Jasper A J
JA
D000339:Affect; D000963:Antimetabolites / Q000008:administration & dosage / Q000494:pharmacology*; D003523:Cycloserine / Q000008:administration & dosage / Q000494:pharmacology*; D004334:Drug Administration Schedule; D006304:Health Status; D006801:Humans; D007858:Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects*; D011939:Mental Recall / Q000187:drug effects; D009483:Neuropsychological Tests; D014145:Trail Making Test
D000963:Antimetabolites; D003523:Cycloserine