A randomized controlled trial of mindfulness combined with transcranial direct current stimulation (tDCS) for improving sleep disorders in firefighters

INTERVENTION: Mindfulness + tDCS group:Experimental Group 1 (Mindfulness + tDCS Group): Received daily mindfulness training (10‐20 minutes) combined with HD‐tDCS stimulation targeting the left dorsolateral prefrontal corte X(F3) (1.5‐2 mA, 20 minutes/session) for 10 consecutive working days.;Mindfulness group:They only received mindfulness training with the same frequency and duration as Experimental Group 1, without receiving real tDCS stimulation.;Waitlist control group:They did not receive any active intervention during the pre‐test and post‐test periods, but corresponding interventions could be provided after the study concluded based on ethical principles.; CONDITION: Sleep Disorders and Emotion Regulation Ability PRIMARY OUTCOME: Sleep Quality;Depression;Anxiety;Perceived Stress;Job Burnout; SECONDARY OUTCOME: Post traumatic stress;Reward Behavior Task (MID);Satisfaction ; INCLUSION CRITERIA: 1. PSQI score >= 7 (indicating poor sleep quality); 2. Active duty firefighters; 3. Voluntarily sign the informed consent form.