# Insights from genetically stratified analyses comparing subtypes of alcohol misuse

## TL;DR

This paper explores different types of alcohol misuse through genetic analysis, showing that a simple internalizing vs. externalizing distinction is too simplistic.

## Contribution

The paper introduces a novel approach to stratify alcohol misuse subtypes using genetic data and psychopathology patterns.

## Key findings

- The binary distinction between internalizing and externalizing subtypes of alcohol misuse is insufficient.
- Stratifying individuals by alcohol use behaviors and psychopathology reduces heterogeneity in genetic research.
- More detailed, person-specific assessments are needed to improve gene discovery and personalized medicine.

## Abstract

In a recent publication, we applied a novel model to address phenotypic heterogeneity in genetic research on alcohol misuse by stratifying individuals based on their patterns of alcohol use behaviours and comorbid psychopathology. In this Commentary, we provide further descriptions of the subtypes of alcohol misuse that emerged from the empirical mixture modelling approach and present new results comparing these groups on sociodemographic characteristics and additional alcohol use outcomes. We take a broad perspective to discuss how these results fit with existing typologies of alcohol misuse and how the results inform future genetic research. Our findings add further evidence that conceptualisations of a binary distinction between ‘internalising’ (relief-seeking) versus ‘externalising’ (reward-seeking) subtypes does not fully capture the complexity of alcohol misuse. However, accounting for individual differences in these dimensions is a promising means to reduce heterogeneity and thereby improve power for gene discovery and, eventually, personalised medicine applications. We argue that more detailed, person-specific assessment of alcohol misuse measures, particularly with attention to longitudinal trajectories, is needed to further advance this important line of research.