SubmissionNumber#=%=#17 FinalPaperTitle#=%=#ransformer_1376 at PsyDefDetect: A QLoRA-Based Generative Framework for Context-Aware Psychological Defense Mechanism Detection ShortPaperTitle#=%=# NumberOfPages#=%=# CopyrightSigned#=%=# JobTitle#==# Organization#==# Abstract#==#Psychological defense mechanisms play a cru- cial role in shaping human responses during emotionally charged conversations, yet remain underexplored in natural language processing. In this work, we address the PSYDEFCONV shared task, which involves classifying defense mechanisms in multi-turn dialogues using clin- ically grounded annotations based on the De- fense Mechanism Rating Scales (DMRS). We propose a generative supervised fine-tuning framework that reformulates the task as con- ditional text generation. A pre-trained causal language model (Gemma-2-2B) is adapted us- ing parameter-efficient fine-tuning (PEFT) with 4-bit quantization, enabling efficient training under limited computational resources. To han- dle class imbalance, we apply random oversam- pling, and we design a prompt-based input rep- resentation to incorporate conversational con- text effectively. Experimental results demon- strate that our generative approach is compet- itive with discriminative baselines while of- fering improved flexibility in modeling sub- tle and context-dependent defensive behaviors. The findings highlight the potential of genera- tive large language models for psychologically grounded dialogue understanding tasks. Author{1}{Firstname}#=%=#Pritha Author{1}{Lastname}#=%=#Saha Author{1}{Username}#=%=#pritha Author{1}{Orcid}#=%=# Author{1}{Email}#=%=#priitha.saha@gmail.com Author{1}{Affiliation}#=%=#Chittagong University of Engineering & Technology(CUET) Author{2}{Firstname}#=%=#Shuvodwip Author{2}{Lastname}#=%=#Saha Author{2}{Username}#=%=#shuvodwip Author{2}{Orcid}#=%=#https://orcid.org/0009-0004-7460-9326 Author{2}{Email}#=%=#shuvodwipsaha@gmail.com Author{2}{Affiliation}#=%=#Chittagong University of Engineering & Technology Author{3}{Firstname}#=%=#Anik Mahmud Author{3}{Lastname}#=%=#Shanto Author{3}{Username}#=%=#anikmahmud Author{3}{Orcid}#=%=# Author{3}{Email}#=%=#anik.mahmudshanto@seu.edu.bd Author{3}{Affiliation}#=%=#Southeast University ========== èéáğö