A 2008 study assessing personality and mood disorder prevalence among homeless people at New York City drop-in centres reported an SPD rate of 65% among this sample. The study did not assess homeless people who did not show up at drop-in centres, and the rates of most other personality and mood disorders within the drop-in centres was lower than that of SPD. The authors noted the limitations of the study, including the higher male-to-female ratio in the sample and the absence of subjects outside the support system or receiving other support (e.g., shelters) as well as the absence of subjects in geographical settings outside New York City, a large city often considered a magnet for disenfranchised people.