Mindfulness and Pushing Away Emotions

With objectless mindfulness, if I am in a bad mood the mood perseveres. I just observe the bad mood but it doesn't easily stop. However, if I applied concentration on an object such as the breath, the mood immediately dissipates and even sometimes vanishes. **Does strong concentration *repress* emotions, or does it process them in a healthy way? In other words, does focusing on the breath still permit the emotions to be experienced naturally despite an absence of thought or feeling?**