I can only speak for myself, family, and friends. Many in my family are atheists, as well as all my friends. We're happy. Suicide rate has many determining factors:
1. Most statistics are either false or inaccurate to varying degrees.
2. Certain cultures have more reliance on religion in their day-to-day lives.
3. Economics have a huge role to play in our level of happiness. Lol. I really don't feel like going in to detail about this one. There's just too much. Sorry.