Scientists identify three subtypes of cocaine addiction

People with a diagnosed cocaine use disorder may fall into three distinct behavioral and neurological subtypes, a discovery that suggests personalized therapies could improve notoriously low recovery rates. Researchers identified these distinct profiles based on emotional regulation, cognitive control, and brain connectivity patterns. The study was published recently in Translational Psychiatry.

Current addiction treatments largely assume a one-size-fits-all model. Up to 85 percent of individuals treated for a cocaine use disorder return to using the drug long-term. Addiction researchers have proposed that the underlying mechanisms driving substance use typically fall into three broad behavioral categories. Some people turn to drugs for reward-seeking or sensation-seeking behaviors.

Others use substances to cope with high levels of negative emotions. A third group experiences deficits in executive function. Executive function involves the mental skills needed to control impulses, plan ahead, and make sound decisions.

University of Minnesota researchers Leyla R. Brucar, Gunner Drossel, and Anna Zilverstand, along with Eduardo A. Garza-Villarreal of the Universidad Nacional Autónoma de México, wanted to map these underlying vulnerabilities. They suspected that previous failures in treating cocaine addiction might stem from a lack of personalized medical approaches. The team had previously identified three distinct functional subtypes in individuals recovering from alcohol and marijuana problems. To test if similar profiles existed in people who use cocaine, they organized a biological investigation utilizing behavioral tests and brain imaging.

The research team analyzed data from 109 participants between the ages of 22 and 39 living in Mexico City. Sixty-one of these individuals met the clinical criteria for an active cocaine use disorder. The remaining 48 participants were healthy individuals who served as a comparison group. These healthy control participants were matched to the drug-using group based on age, gender, and education levels.

Participants completed a lengthy series of clinical interviews, self-reported questionnaires, and behavioral tasks. These assessments evaluated their emotional states, their cognitive abilities, and their levels of impulsivity. The researchers then fed the results into a mathematical model designed to uncover hidden groups within multidimensional datasets. This mathematical tool sorts individuals based on shared psychological patterns across multiple variables.

Three distinct individual profiles emerged within the group of people who consume cocaine. About a third of the users fell into what the researchers labeled a “relief type.” These individuals exhibited high levels of negative emotions, including depression, anxiety, anger, and neuroticism. They also displayed higher rates of other mental health symptoms and personality disorders.

Another quarter of the participants fit the “cognitive type” profile. These individuals primarily struggled with executive function. They reported much higher levels of impulsivity across the board. Specifically, they showed a strong tendency to act on a whim without engaging in forward planning.

The remaining participants were grouped into an “undefined type.” Compared to the healthy control group, these individuals did not show obvious cognitive or emotional impairments on the tests provided. They actually demonstrated very low levels of antisocial behavior, indicating a generally high level of social functioning in their daily lives.

To see if these behavioral profiles matched actual physical differences in the brain, the researchers examined functional magnetic resonance imaging scans for the participants. They measured resting-state functional connectivity, which maps how different regions of the brain communicate with one another. This mapping is done while a person is awake but not focused on any specific task. By tracking blood flow to various brain regions over time, scientists can see which areas naturally exchange information.

Each behavioral subtype displayed unique brain connectivity patterns that corresponded with their psychological tests. In the relief type, brain regions associated with memory, emotion processing, and bodily awareness showed altered communication pathways. In the cognitive type, abnormal brain connectivity appeared in areas governing motor planning and visual processing. The cognitive group also showed altered connectivity in the frontoparietal network, a brain system heavily involved in cognitive control and decision making.

The undefined type also showed altered brain connectivity compared to healthy individuals. Their neural disruptions appeared in networks linked to motor planning, the brain’s baseline resting state, and regions associated with the internal reward circuitry. The researchers noted that these brain patterns looked somewhat similar to reward-seeking profiles found in other studies.

Despite their varied behavioral profiles, all three subtypes shared one common neural feature. Every individual with a cocaine use disorder exhibited altered brain connectivity in the salience network. This brain system is responsible for directing a person’s attention toward important stimuli in their environment. In addiction, this network often incorrectly flags drug-related cues as highly important, redirecting a person’s focus away from healthy activities.

None of the three groups differed regarding their actual cocaine habits. Individuals across all three subtypes began using the drug around the same age in their lives. They also consumed similar weekly doses and suffered from the same levels of addiction severity. The underlying psychological path to their substance use differed entirely, but the resulting behavioral severity looked identical from the outside.

A main limitation of the study is that the available psychological tests were heavily focused on negative emotions and cognitive control. The dataset lacked extensive measures for reward-seeking behavior. The researchers strongly suspect that the undefined type might actually represent a sensation-seeking group, but they could not confirm this without the proper behavioral testing questionnaire data.

Adding to the limitations, the number of participants providing brain imaging data was relatively modest for a neuroimaging experiment. Future research will need to replicate these findings in other groups of individuals. The scientists hope to investigate whether these brain and behavior profiles hold true across other demographic populations. They want to see if the underlying mechanisms remain consistent regardless of the primary drug of choice.

Establishing reliable screening tools for these subtypes could eventually lead to more personalized therapies in clinical settings. A person fitting the relief type might benefit from psychiatric medications that target anxiety, or therapies focused on emotional coping mechanisms. Treatment plans that fail to address this underlying emotional dysregulation might naturally fall short for these patients.

Conversely, an individual in the cognitive type group might experience better outcomes with therapies that train the brain to improve impulse control. They could benefit from experimental neuromodulation techniques aimed at improving the function of the prefrontal cortex. Recognizing these different biological entry points into addiction presents a tailored path toward medical recovery.

The study, “Subtypes of cocaine use disorder and their neurobehavioral profiles,” was authored by Leyla R. Brucar, Gunner Drossel, Eduardo A. Garza-Villarreal, and Anna Zilverstand.