It’s thought that antidepressants work by increasing levels of a group of chemicals in the brain called neurotransmitters. Certain neurotransmitters, such as serotonin and noradrenaline, can improve mood and emotion, although this process isn’t fully understood.

Increasing levels of neurotransmitters can also disrupt pain signals sent by nerves, which may explain why some antidepressants can help relieve long-term pain.

While antidepressants can treat the symptoms of depression, they don’t always address its causes. This is why they’re usually used in combination with therapy to treat more severe depression or other mental health conditions caused by emotional distress.