Cross scale transfer improves depression score prediction across languages

Cross-Scale Transfer Learning for Depression Severity Prediction: From PHQ-8 to HAMD-17 Across Languages and Clinical Paradigms

Computation and Language

Summary

Predicting how severe someone’s depression is can help doctors provide better care, but there isn’t always enough data for training computer models. The authors tried teaching a model first on English data with one type of depression scale, then adjusted it to work on Chinese data with a different scale. This step-by-step approach worked better than training only on the smaller Chinese dataset or using other methods. They also found that using native language transcripts helped more than machine-translated text. However, this study is an early test and not meant for clinical decision making yet.

What this means in practice

  • For clinical data scientists: Improve depression severity prediction models by transferring knowledge from larger English datasets to scarce Chinese clinical data using sequential fine-tuning.
  • For multilingual medical ai developers: Build better AI tools that adapt depression assessment models across different languages and clinical scales with limited target data.

Tested on one dataset.

Authors

Wenjie Feng, Sahba Zojaji, Satoshi Nakamura

Abstract

This work addresses continuous depression-severity score prediction from clinical interview transcripts under data scarcity. We propose a sequential low-rank adaptation (LoRA) protocol for cross-scale transfer: a Qwen3 backbone with a bounded regression head is first fine-tuned on the English DAIC-WOZ dataset (189 avatar-mediated sessions, PHQ-8), and the adapter then initializes fine-tuning on the Chinese PDCH dataset (100 real clinical consultations, HAMD-17), where a reinitialised, scale-specific head predicts the clinician-assigned score. All configurations use patient-level stratified 5-fold, 2-repeat cross-validation. On the data-scarce HAMD-17 target, the sequential protocol attains the best point-estimate MAE , RMSE, and macro-$F_1$ on both 0.6B and 1.7B backbones, outperforming target-only training and non-LLM baselines---4.96/6.59/0.36 with Qwen3-0.6B and 4.38/5.62/0.46 with Qwen3-1.7B. Ablations suggest that correctly aligned source supervision gives the best point estimates (unsupervised exposure and shuffled-label controls also show partial gains), that native-Chinese target input outperforms machine-translated English input, and that the reversed order yields no clear gain within run-to-run variance. The study is an exploratory, single-site internal evaluation: it does not establish screening or diagnostic utility, nor separately identify the contribution of the scale, language, or paradigm shifts. To our knowledge, no prior study evaluates this specific DAIC-WOZ-to-PDCH sequential transfer setting.