Antibiotic use has been linked to higher anxiety and depression risk by disrupting gut bacteria that regulate brain chemistry and stress response Human studies show antibiotics lower key calming neurotransmitters and activate inflammatory brain cells tied to anxious behavior Repeated or early-life antibiotic exposure increases long-term vulnerability to anxiety, depression, and cognitive strain Antibiotics disrupt gut-brain signaling in ways that trigger anxiety, sleep problems, and emotional instability even in people with no prior mental health history Reducing unnecessary antibiotic use and restoring gut stability helps calm anxiety by addressing the biological cause rather than masking symptoms