The Short Version
The core claim is well-supported. OSHA, CDC/NIOSH, the APA, and peer-reviewed research consistently link work-related stress to cardiovascular disease, depression, anxiety, and other health problems. NIOSH states work problems are "more strongly associated with health complaints than any other life stressor." The claim earns a minor downgrade because most evidence addresses workplace stress broadly rather than isolating office jobs specifically, and the word "significantly" isn't precisely quantified — but office workers clearly fall within the populations studied.