The catch 22 of addiction: social-cognitive function
RESEARCH
Does being lonely or feeling empty lead to greater risk for addiction? Does addiction then lead to greater isolation and feelings of emptiness?
My dissertation is ongoing and aims to address:
Feel like you don't look forward to things anymore? This could lead to making impulsive bad decisions. I investigate these traits in people who switched from smoking to vaping.
Does withdrawal make time crawl? Time passes slower for people going through withdrawal, and it may be related to anticipatory anhedonia.
How does your brain respond to a social media "like" when in withdrawal?
(shown) This is preliminary data of the brain receiving a social media "like" in my study. The top panel shows activation in the dopamine reward center, and the bottom panel shows value (how much did you enjoy getting that like?) and self-referential regions (how did that make you feel about yourself?).
Symptom subtypes in depression are related to medication response
Anhedonia is the inability to feel joy. It is a core symptom of depression that doesn't get better after treatment with gold standard antidepressants (SSRIs).
I built random forest classifiers to walk through a list of survey questions related to anhedonia to identify which ones were best at predicting who would not respond to medication.
These classifiers identified the 6 most important predictive factors: Anhedonia (low joy), Dysphoria (hopelessness), Distress (strong negative emotions), Anxiety (worry about the future), Cognitive function (focusing or remembering), and Motivation (moving toward goals).
Unsupervised cluster analysis found 4 empirical "types" (clusters) of depression across people in 3 groups: ARD (antidepressant resistant depression), MDD (non-resistant depression), and HC (healthy controls).
People with ARD mostly occupy clusters 1 and 3. Cluster 1 tended toward high negative emotion (greater stress and anxiety), while cluster 3 tended toward low positive emotion and functioning.
Work personality affects accuracy of threat detection
Some people are motivated by security, vigilance, and duty, while others are motivated by growth, ideals, and aspirations. This has been captured in Regulatory Focus Theory (Higgins, 1997), created to describe how people behave in work situations.
The first personality type tends to perform better on a gamified computer task where participants had to quickly distinguish between an armed vs. unarmed man.
This meant they were more accurate for detecting a threat signal without sacrificing speed.
This has implications for recruitment and training of personnel in security, law enforcement, and military positions.
People with depression are less likely to learn from positive outcomes
Reinforcement learning is governed by the dopaminergic reward circuit. For people with depression, there is reduced dopamine activity. This leads to symptoms of not only decreased joy, but may also impair learning from positive events.
I investigated this using a reinforcement learning task called BeanFest (Fazio et al., 2004). People who had more depression and anxiety tended to avoid new beans in this game ("do not select the bean"), self-sabotaging the opportunity to be rewarded with health points.
People who were successfully treated with antidepressants (SSRIs) were actually worse at learning bad beans, but were not better at learning the good beans. This aligns with previous research showing that antidepressants reduce our sensitivity to negative events instead of increasing sensitivity to positive ones.
Useful memory strategy while drinking
Prospective memory is remembering events or tasks to be completed in the future. They can be anchored to a specific daily event (for example, remembering to take a Rx medication when eating dinner), or time of day (remembering your Zoom call at 3PM).
Alcohol impairs memory encoding, and this includes prospective memory. I used a computer game called Virtual Week (Rendell & Craik, 2001) to test whether an intervention called implementation intentions (Gollwitzer, 1999) could improve prospective memory during alcohol intoxication using a double-blind randomized controlled trial.
While this was a pilot study with a small sample size, I found that using this memory strategy helped people in the alcohol group perform at the same levels as the placebo group.
