I've had serious depression w/o suicidal ideation. My worst episodes of course had those suicidal thoughts, but those thoughts are not always a "given" when I'm in a depressed state. (They have always been present when I'm in a mixed state though.) Sometimes I just have an overwhelming sense of shame, foolishness, despair, sadness, crying, inability to function or desire to interact with other people, etc. I imagine people who have a bipolar diagnosis have probably experienced both at one time or another.