Antidepressants are essentially used to treat depression, or as mood stabilisers. The best treatment for depression may include psychological treatment, medicine, and support within the community. Antidepressants may also be useful in the treatment of anxiety-related disorders, for example common disorders such as generalised anxiety disorder, eating disorders, obsessive-compulsive disorder, social phobia, and post-traumatic stress disorder. With further research and studies being conducted, newer antidepressants are being developed to advance treatments to reduce or minimise the unwanted effects caused by older antidepressants.

Antidepressants and the Way They Act Within the Body

Research has shown that the majority of people suffering from depression and anxiety disorders tend to have an imbalance of certain natural chemicals within the brain. For example, serotonin is one of the most common chemicals to show an imbalance in people suffering from depression. Serotonin is a chemical used to activate the nerve cells in the brain and plays a major role in regulating our mood. Doctors believe selective serotonin reuptake inhibitor (SSRI) medicines relieve depression by making more serotonin available to activate nerve cells.

Antidepressant medicines have shown to aid the brain to restore its usual chemical balance and hence reduce symptoms.

How Long Do They Take to Work?

Effects and improvement after starting antidepressants varies from patient to patient, however, it can take up to six weeks after the first dose of medicine before an improvement is observed. Slight positive mood changes can be seen within the first week or two of starting the medicine. The maximum benefit is felt after six months; hence people suffering from depression should be encouraged to be patient with their antidepressants to allow for the medicine to reach the full effect.

Antidepressant medicines are generally very effective. Around 70% of people with major depression start to feel better with the first type of antidepressant prescribed by their medical practitioner.

Side Effects of Antidepressant Medicine

There are many different types of drugs used in the treatment of depression, including SSRI, atypical antidepressants, tricyclic antidepressants, and monoamine oxidase inhibitors. Most antidepressant groups tend to have similar side effects. It is due to the unwanted effects that most people suffering from depression tend to stop, or not be compliant, with taking their medicines. Weight gain, dry mouth, sleep disturbances, nausea, blurred vision, sweating, lower sexual response are some of the common side effects associated with the use of these medicines. These may be minimised or overcome by consulting a medical practitioner in order to discuss the unwanted effects, and the possible treatments that can be recommended to them, for example seeing a dietician to help with weight management, or taking their antidepressants in the morning to prevent insomnia.

The Most Commonly Prescribed Antidepressants

SSRI are one of the common groups of antidepressants prescribed. The SSRIs include well-known antidepressants, such as Prozac® and Zoloft®. They are mainly prescribed since they tend to have fewer unwanted effects compared to the older tricyclics, and other antidepressant groups. The effect of SSRIs increasing the level of serotonin in the brain helps to regulate mood.

Other Treatment Options

It is essential to be aware that there are effective treatments for depression, but there is no single treatment that is right for everybody. It is important to find a treatment that works for the patient, which can take time in some individuals. Psychological treatments, such as cognitive behaviour therapy (CBT), can be used in combination with medicine, or alone for treatment of depression. Studies have shown that in some individuals, antidepressants and CBT are as effective as each other for improving symptoms of moderate depression. However, the effects of CBT last longer than those of antidepressants after the therapy has been stopped. It is important for patients to talk to their medical doctor to find the most suitable therapy for them.

Lifestyle changes and exercise can also be helpful; however they are not usually enough to treat depression on their own. There are also some complementary or alternative medicines that can be used, however the effectiveness of these types of medicines has not been proven. For example, St John’s Wort is classified as an alternative medicine and is used in the treatment of depression, however can have dangerous interactions with other medicines, including antidepressants. Therefore it is important for patients to inform their doctor if they are also using other therapies whilst taking prescription antidepressants.


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