Harvard Kennedy School Professor Robert D. Putnam led a discussion about the psychological benefits of community building last night in the keynote event to Harvard’s ninth annual Mental Health Awareness Week.

Putnam, a public policy expert who has written extensively on the decline in social and civic engagement among Americans, focused his remarks on the importance of forming social networks to promote psychological well-being.

“As a risk factor for premature death, social isolation is as big a risk factor as smoking,” Putnam said in his speech, which was cosponsored by the Wellness Center, the Harvard Student Mental Health Liaisons, and the Harvard Mental Health Awareness and Advocacy Group.

Putnam also discussed a number of historical trends that led Americans to join fewer clubs, spend less time with their families, and disengage socially over the last third of the 20th century.

“Television is about half of the story, actually,” Putnam said. “Watching the news is good for your civic health. But most people aren’t watching the news. They’re watching ‘Friends,’ instead of having friends.”

Putnam also noted that the generation of individuals who grew up in the aftermath of Sept. 11 appeared to be reversing this trend by forming stronger and more lasting social connections. But he tempered this optimism by pointing out that the trend is occurring along class lines—working class youth are more likely than ever to be emotionally and interpersonally isolated.

“I do think that class gap is an important qualification on what would otherwise be a good news story—the story that this is the generation that is going to save America,” Putnam said.

Following his speech, Putnam entertained questions from his audience about Facebook, immigration, and the implications of increasing diversity on communities.

“I think he’s a fantastic speaker,” said Elizabeth A. Goodman-Bacon ’10, co-director of the Harvard Student Mental Health Liaisons. “He strikes a good balance of providing evidence with accessible discourse on what’s actually happening in America today.”

Goodman-Bacon added that she was pleased to see a diverse group of Harvard undergraduates and graduate students turn out for the event.

Paul Barreira, the director of behavioral health and academic counseling at Harvard University Health Services, said he had sought out Putnam to deliver the keynote speech as part of an ongoing effort to create a caring and supportive community at Harvard.

“If you ever check into Harvard FML postings, you’ll see things like, ‘I’m so alone, my life sucks,’” Barreira said. “That’s why we asked him to speak.”

Mental Health Awareness Week will conclude tomorrow with mental health study breaks in all of Harvard’s undergraduate houses.

—Staff writer Evan T.R. Rosenman can be reached at erosenm@fas.harvard.edu.