By Cristina Mestre
This month’s issue of Psychology
of Addictive Behaviors
takes on the important topic of how brain imaging research can help to improve
psychotherapy for addictive behaviors.
background, neuroimaging (brain imaging) includes a variety of methods that are
used to examine brain structure and functioning. Brain imaging methods include:
Resonance Imaging (MRI): a widely used,
non-invasive method that is generally safe (it does not involve radiation), and
produces an image that looks like an x-ray.
MRI (sMRI): this can show various brain structures, including damage to brain
tissue, such as lesions and tumors.
MRI (fMRI): this is used to study activity in specific brain regions, usually in
response to a specific experimental task (e.g., seeing a flash of light).
Tensor Imaging (DTI): this is another popular, non-invasive and safe imaging
method which can show white matter tracts in the brain that facilitate communication between
of the special issue of the journal was motivated by the urgent need to improve
treatment for addictive behaviors. Current
psychotherapies for addictive behaviors are only moderately successful in
helping people to “stay clean,” with relapse as a relatively common outcome. This modest success rate for treatment is
partly due to our limited understanding of how and why psychotherapy works,
particularly at the level of brain structure and functioning. The idea behind
the special issue is that by understanding how effective psychotherapies have
an impact on brain structure and functioning, we will be able to design more
effective interventions with stronger and longer lasting effects.
|Structural MRI of Dr. Chung's brain.|
Q: What exactly does “psychotherapy
mechanisms of change for addictive behaviors” mean, and how does neuroimaging
play a role?
A “mechanism of change” explains how a treatment works. For example, in cognitive behavioral therapy
(CBT), a proposed “active ingredient” that explains how the therapy works is the
development of skills to cope with craving, such as actively seeking social support for abstinence, rather than giving
in to the urge to use. Effective use of coping skills might involve an increase
in the activation of brain areas that are associated with the regulation of
behavior, such as the prefrontal cortex (an area of the brain just behind the
forehead). Neuroimaging could play an important role in helping us to
understand how this “active ingredient” of treatment works by showing, for
example, that effective treatment increased activation (compared to before
treatment) in an area of the brain associated with the regulation of behavior
and emotions, which in turn was associated with better outcomes. Understanding
the brain-based mechanisms underlying successful recovery is critical to
designing and delivering effective treatment.
Q: How can neuroimaging help us to understand the science
neuroimaging studies have shown that chronic, heavy substance users, compared
to their healthy counterparts (same age and sex), show deficits in brain
structure. For example, alcoholic patients have smaller regional brain volumes,
likely due to heavy alcohol use, compared to healthy adults. Chronic substance
users also tend to show alterations in brain functioning. As an example,
chronic substance users typically show less activation in brain regions (e.g., in
the prefrontal cortex) that are associated with the ability to effectively
control behavior and regulate emotions. It’s not clear how much these
differences are due to heavy substance use, or if they existed prior to heavy
substance use. However, emerging research suggests that youth at high risk for
substance use show less activation in brain regions associated with behavioral
control, even before starting substance use. But we still don’t know a lot
about how the brain changes in response to psychotherapy.
Q: How can neuroimaging help us predict which treatments
will work and which will be less effective?
starting to understand the potential of neuroimaging to help us predict which
treatments will work, and for whom they will work best. One of the studies in
the special issue found that greater integrity of white matter in the
prefrontal cortex, a region associated with the ability to regulate behavior,
predicted lower severity of alcohol problems following treatment in
adolescents. This result suggests that there are brain-based characteristics at
the start of treatment that could predict better outcome. The result also
suggests that finding ways to improve white matter integrity, such as exercise
and nutrition, and maintaining abstinence from substance use, are important
Treatment researchers are not usually trained in neuroimaging (but that
may change!), and few neuroimaging researchers specialize in addictions
treatment (which we hope will change!). The special issue was intended to
foster collaboration between two fairly specialized areas, to begin to
understand the process by which psychotherapy, which can be thought of as a
specialized form of learning, has an impact at the level of brain structure and
functioning. Understanding changes at the level of the brain could inspire
novel treatment methods that target specific brain-based mechanisms that underlie
sustained recovery from addiction.