Prosocial learning and decision-making in alcohol use disorder

Background:

Alcohol Use Disorder (AUD) is one of the most prevalent and burdensome psychiatric conditions worldwide. Despite evidence-based treatments, clinical outcomes remain modest, and many patients continue to suffer. One overlooked factor may be interpersonal functioning. While previous research has largely focused on clinical symptoms such as craving and withdrawal, less is known about how prosocial behavior-acts intended to benefit others-relate to the development, maintenance, and treatment of AUD.

Aims:

The overarching goal of this thesis was to investigate prosocial behavior in relevance to AUD using a multimodal approach. Specifically, it aimed to:

(1) examine prosocial learning and decision-making in individuals with AUD (Studies I-II), (2) test whether intranasal oxytocin could modulate prosocial decision-making and preferences in AUD (Study III), and (3) evaluate whether individual differences in prosocial and antisocial behavior predict future substance use and psychiatric symptoms in youth and adult clinical populations (Studies IV and V).

Methods:

The thesis includes five empirical studies involving clinical, experimental, and longitudinal designs.

· Studies I-II assessed altruism, fairness, trust, third-party punishment and social reward learning using behavioral economic tasks and reinforcement learning paradigms in large samples of individuals with AUD and matched healthy controls (N=500 total).

· Study III was a double-blind, placebo-controlled clinical trial (N=206) evaluating the causal effects of intranasal oxytocin on prosocial decision- making and preferences.

· Study IV used nationwide longitudinal data (N=3,817 adolescents) to examine whether antisocial and prosocial behaviors at age 15-16 predicted substance use at age 17-18.

· Study V used a 1-year prospective cohort of adults with psychiatric diagnoses (N=4,484) to investigate how different subtypes of prosociality predicted later psychiatric symptom trajectories.

Results:

· Study I showed that individuals with AUD consistently exhibited lower levels of altruism, fairness, and reciprocal trust across both lab and online samples. These effects were not explained by recent drinking or comorbid psychiatric symptoms, but were linked to attentional focus and moral reasoning indicating trait-like deficits in core prosocial domains.

· Study Il found that social reward learning-learning how one's actions benefit others-was intact in AUD, suggesting that reduced prosociality reflects a motivational deficit rather than a learning impairment.

· Study III showed that intranasal oxytocin did reduce prosocial decision- making in AUD, in particular for those with an individualistic disposition. However, oxytocin increased prosocial preferences-especially among individuals lower emotional empathy and lower attachment anxiety- suggesting that oxytocin may influence social motivation in terms of preferences, even if it does not translate directly into behavior.

· Study IV showed that antisocial traits in terms conduct problems and criminal behavior and redued institutional trust were strong and independent predictors of later substance use.

· Study V revealed that specific subtypes of prosociality differentially predicted psychiatric trajectories: anonymous helping was protective against future AUD symptoms, whereas public and emotional helping were associated with greater risk for SUD and anxiety, respectively.

Conclusions:

This thesis demonstrates that prosocial behavior in AUD is not a unitary construct but varies in its manifestations, mechanisms, and predictive value. Reductions in prosocial decision-making appear to be stable, trait-like vulnerabilities rather than transient effects of alcohol use. Although the oxytocin system seems to play a role in explaining reduced prosociality in AUD, individual differences in emotional processes is crucial to predict the effect of administering oxytocin endogenously. Moreover, different subtypes of prosociality-particularly anonymous versus public and emotionally driven helping-carry distinct implications for psychiatric risk and resilience. Together, these findings suggest that social functioning in AUD is best understood not as a general deficit, but as a nuanced and dynamic domain that differs between individuals with the same patient group. Future research should investigate individual differences in social behavior by applying computational approaches to objectively characterize the underlying causal mechanisms and subsequently design corresponding personalized treatments.

Clinical and Research Implications:

The results underscore the potential of incorporating objective social behavioral measures into clinical assessment and treatment planning for AUD. Interventions should be developed for targeting social motivation. Pharmacological interventions such as oxytocin may serve as useful adjuncts in modulating social motivation in subgroups of AUD with low emotional responding , though further research is needed. Finally, the predictive role of specific prosocial behaviors in psychiatric outcomes highlights the potential value of early social interventions to prevent later substance use and emotional distress.

List of scientific papers

I. Jangard, S., Lindström, B., Khemiri, L., Pärnamets, P., Jayaram- Lindström, N., & Olsson, A. (2022). Alcohol use disorder displays trait- related reductions in prosocial decision making. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, 7(9), 925-934. https://www.biologicalpsychiatrycnni.org/article/S2451- 9022(22)00118-5/
https://doi.org/10.1016/j.bpsc.2022.05.002

II. Jangard, S., Lindström, B., Khemiri, L., Jayaram-Lindström, N., & Olsson, A. (2025). Dissociating social reward learning and behavior in alcohol disorder. Translational Psychiatry, 15(1), 30. https://www.nature.com/articles/s41398-025-03236-3
https://doi.org/10.1038/s41398-025-03236-3

III. Jangard S., Guterstam, J., Gustavsson, E., Asperholm., M., Helldén, J., Olsson, A., & Jayaram-Lindström, N. The Impact of Oxytocin on Prosocial Decision Making and Preferences in Males with Alcohol Use Disorder [Manuscript]

IV. Jangard, S., Olsson, A., Molero, Y., Jayaram-Lindström, N., & Raninen, J. (2025). Antisocial and prosocial behaviors as predictors of subsequent substance use in adolescence. Addictive Behaviors, 166, 108308. https://www.sciencedirect.com/science/article/pii/S0306460325000 632
https://doi.org/10.1016/j.addbeh.2025.108308

V. Jangard, S., Vieira, J. B., Garke, M. Å., Ojala, O., Månsson, N.T., K., Sörman, K., El Alaoui, S., Hedman-Lagerlöf, M., Rozental, A., Forsström, D., Lundin, J., Shahnavaz, S., Lundgren, T., Olsson, A., & Jayaram-Lindström, N. Situation-specific Prosocial Behaviors Predict Substance Use and Anxiety Symptoms in Psychiatric Disorders [Manuscript]