Antidepressants are medications primarily used to treat depression and other mental health conditions such as anxiety and obsessive-compulsive disorder. They work by increasing the activity of certain chemicals in the brain called neurotransmitters, particularly serotonin, noradrenaline (norepinephrine), and sometimes dopamine. These neurotransmitters are linked to mood regulation and emotion. By boosting their levels or activity, antidepressants can help improve mood and relieve symptoms of depression and anxiety

. The exact mechanism of how antidepressants work is not fully understood, but it is believed that increasing neurotransmitter levels helps correct chemical imbalances that affect mood. Some antidepressants also disrupt pain signals sent by nerves, which may explain their use in treating long-term pain conditions

. Antidepressants typically take 1 to 2 weeks before benefits are noticed, and they are often prescribed alongside talking therapies such as cognitive behavioral therapy (CBT) to address underlying causes of depression

. There are different types of antidepressants, including:

• Selective serotonin reuptake inhibitors (SSRIs)
• Serotonin-norepinephrine reuptake inhibitors (SNRIs)
• Atypical antidepressants
• Older classes like tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs)

Each type works slightly differently but generally aims to increase neurotransmitter activity in the brain

. In summary, antidepressants help relieve the symptoms of depression and some other mental health or physical conditions by increasing brain chemicals that regulate mood and emotion, though they do not always address the root causes of these conditions