Relapse is a painful reality of drug addiction, and
people have dedicated their lives to researching ways to improve relapse
prevention. The majority of this research focuses in psychosocial treatments
(sometimes pharmacotherapy) to prevent the individual from relapsing when they
are conscious of the danger of a lapse. Dr. Young and colleagues (2014) decided
(quite brilliantly) to determine if pharmacotherapy could possibly be used to
inhibit subliminal drug cues. Substances and cues that are conditioned with
those substances have been shown to reliably lead to neural activation and the
release of dopamine in the mesolimbic region of the brain (i.e. the ventral
striatum and amygdala). Previous research has shown that this activation can
occur even if the individual is not aware of the drug cues they are being
presented with. There is a drug called baclofen, and it fuctions as a GABAb
receptor agonist and has been supported as reducing mesolimbic neural
activation due to drugs or drug-cues, dopamine release, and drug-seeking
behavior in animals.
The researchers used 20 cocaine using men and split
them up between a placebo group and a baclofen group. The participants were put
in an fMRI machine and a procedure called “backward-masked cue task” was used.
Basically, the participants were shown an image of a just a fixating point (a
cross) for 500 ms. Then they were shown a drug, sexual, or aversive subliminal
cue for only 33ms. After the target cue
they were shown a neutral cue for 467 ms, and finally, they saw the fixation
cross again for 1000 ms. First, the researchers found that cocain, sexual, and
aversive cues lead to mesolimbic activation. This is important to establish for
the other findings. The data show that there was a significant interaction on
neural activation between the group (baclofen/placebo) and the cue condition
(cocaine vs neutral, sex vs neutral, and aversive vs neutral). The other
finding was that baclofen reduced the activation in the mesolimbic region of
the brain in response to the subliminal cocaine cues, but not the sexual or
aversive cues for the baclofen-treated group.
These results are fascinating, but they must be
taken with caution due to the homogenous, small sample. Another limitation is
the fact that fMRI machines were utilized and a wise consumer must look at how
the analyses were run with fMRI data. Overall though, the findings could mean a
great deal to an entire community. Relapse prevention is vitally important, and
this article provides the first empirical research that suggests that
pharmacotherapy could influence the human motivational response to drugs before
the person is even aware of it.
Young,
K. A., Franklin, T. R., Roberts, D. C. S., Jagannathan, K., Suh, J. J.,
Wetherill, R. R., Wang, Z., Kampman, K. M., O’Brien, C. P., & Childress, A.
R. (2014). Nipping cue reactivity in the bud: Baclofen prevents limbic
activation elicited by subliminal drug cues. The Journal of Neuroscience, 34(14), 5038-5043. doi:
10.1523/JNEUROSCI.4977-13.2014
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