A recent report by the American Psychosomatic Society claims that non-smokers exposed to secondhand smoke at home or in the workplace were found to be twice as likely as those not exposed to secondhand smoke to have major depression. While an older Japanese study came to a similar conclusion, this particular study measured cotinine levels, a chemical found in the blood after ingesting cigarette smoke. Frank Bandiera, a public health researcher at the University of Miami School of Medicine claims the supposed link may be tied to neurotransmitter density in the brain. Bandiera claims that smokers generally have more dopamine in the brain, a chemical related to anxiety and depression. The study goes further on to claim that inhaling secondhand smoke increases risk of memory problems and dementia after age 50.