Some U.S. studies have found that the majority of gay male couples are in monogamous relationships. A representative U.S. study in 2018 found that 32% of gay male couples had open relationships. Research by Colleen Hoff of 566 gay male couples from the San Francisco Bay Area funded by the National Institute of Mental Health found that 45 percent were in monogamous relationships, however it did not use a representative sample. Gay actor Neil Patrick Harris has remarked, "I'm a big proponent of monogamous relationships regardless of sexuality, and I'm proud of how the nation is steering toward that."