Antidepressant Drugs Overview

Antidepressant drugs can be invaluable in the treatment of major mood disorders. By affecting certain key neurotransmitters like dopamine and serotonin, they can restore chemical balance to the brain that underlies clinical depression.

Due to their action on delicate neurological systems, antidepressant drugs may also have unintended physical and psychological effects. Like other prescription medication, antidepressants carry some risk of abuse and dependence.

What Are Antidepressant Drugs?

Antidepressants are classes of drugs primarily designed to treat depressive disorders, though they’re also used to treat other psychological conditions such as PTSD and personality disorders. Under this umbrella category are several specific types of antidepressant drugs that are differentiated according to the effects they have on the brain and the neurotransmitters they affect.

Common Antidepressant Drugs

Selective serotonin reuptake inhibitors (SSRIs)

SSRIs are some of the most commonly prescribed antidepressant drugs because they tend to have less severe side effects than other classes of antidepressants. They work by inhibiting the reuptake of serotonin, which increases the neurotransmitter’s availability in the brain. Serotonin is associated with feelings of happiness so increased availability of it decreases feelings of depression.

Serotonin and norepinephrine reuptake inhibitors (SNRIs)

SNRIs work similarly to SSRIs, inhibiting the reuptake of both serotonin and norepinephrine. This class of antidepressant drugs can treat depression as well as some anxiety and attention disorders. Because they have an effect on two different important neurotransmitters, they may be more effective.

Serotonin antagonist and reuptake inhibitors (SARIs)

SARIs also work primarily on serotonin but have a dual function, as an antagonist and a reuptake inhibitor. This means that in addition to preventing the reuptake of serotonin, they block the function of the serotonin transporter protein so more serotonin is actively available. Though they’re approved for use against depression, they are also sometimes used for anxiety or insomnia.

Monoamine oxidase inhibitors (MAOIs)

MAOIs primarily affect monoamine oxidase, which is an enzyme that breaks down serotonin, dopamine, and epinephrine among others. By preventing this enzyme from working, these neurotransmitters cannot be reabsorbed, leading to their increased availability in the brain. MAOIs can have severe side effects and can cause a dangerous accumulation of serotonin in the brain.

Tricyclics

Tricyclic medications prevent serotonin and epinephrine from being reabsorbed. Because they’re associated with severe side effects including high blood pressure and heart complications, they are only prescribed in cases of severe depression that is resistant to other forms of medication.

Tetracyclics

Like tricyclics, tetracyclic antidepressants have largely fallen out of favor due to their side effects, but they can still be effective in treating severe and treatment-resistant depression.

Norepinephrine and dopamine reuptake inhibitors (NDRIs)

NDRIs work on norepinephrine and dopamine instead of serotonin, preventing their reuptake and increasing their availability in the brain. They’re newer than other antidepressants and carry fewer risks of side effects like weight gain and lowered sex drive.

Examples Of Antidepressant Drugs

Selective serotonin reuptake inhibitors (SSRIs)

Prozac
Zoloft
Lexapro
Paxil
Celexa

Serotonin and norepinephrine reuptake inhibitors (SNRIs)

Cymbalta
Effexor
Pristiq
Fetzima
Khedezla

Serotonin antagonist and reuptake inhibitors (SARIs)

Axiomin
Normarex
Psigodal
Serzone
Nefadar

Monoamine oxidase inhibitors (MAOIs)

Nardil
Emsam
Marplan Parnate

Tricyclics

Tofranil
Elavil
Pamelor

Tetracyclics

Mazanor
Remeron
Ludiomil
Asendin

Norepinephrine and dopamine reuptake inhibitors (NDRIs)

Wellbutrin
Zyban Aplenzin

Are Antidepressant Drugs Addictive?

Though antidepressant drugs do not have the same potential for addiction as other drugs, dependency on antidepressants can occur due to their positive effect on mood. Withdrawal after use is discontinued can be similar to withdrawal from drugs like opioids, heroin, or alcohol. Tolerance to antidepressants may occur in some individuals, requiring a change in dosage or medication type to continue having an effect.

Though addiction to antidepressant drugs is not widely recognized in the medical community, these detrimental effects are reported by antidepressant users especially after long-term use. Some antidepressants, like tricyclics, carry the risk of overdose after long-term use and use at high doses. Overdose is also more likely in cases of antidepressant abuse where it is taken at doses higher than prescribed or taken with other substances.

Short-Term Effects Of Antidepressant Drugs

Short-term effects of antidepressants are more common at first, improving with use over a longer period of time. These effects vary according to the specific class of antidepressant.

Common side effects of selective serotonin reuptake inhibitors (SSRIs) and serotonin-noradrenaline reuptake inhibitors (SNRIs) may include:

Feelings of anxiety and agitation
Dizziness
Loss of appetite
Indigestion
Headaches
Insomnia
Diarrhea
Constipation Lowered sex drive

Side effects of tricyclic and tetracyclic antidepressants may include:

Constipation
Drowsiness
Dizziness
Dry mouth
Blurred vision
Excessive sweating
Tachycardia
Confusion
Urinary retention

Long-Term Effects Of Antidepressant Drugs

In addition to effects that may be felt in the short-term, prolonged use of antidepressant carries the risk of some long-term effects. These include:

Weight gain
Sexual problems including erectile dysfunction in men and inability to reach orgasm
Feeling emotionally numb
Dependence
Potential for abuse
Suicidal ideation

Withdrawal from Antidepressant Drugs

Withdrawal symptoms when discontinuing antidepressant medication is common after prolonged use and when use was stopped abruptly. Symptoms are known as antidepressant discontinuation syndrome, a condition that can last one to several weeks. Withdrawal onset occurs one to two days after antidepressant use has stopped.

Symptoms of antidepressant withdrawal include:

Anxiety
Headaches
Dizziness
Irritability
Flu-like symptoms
Nausea
Sensations of electric shock
Increased depression

How to Safely Stop Using Antidepressant Medications

To reduce the possibility of antidepressant drug withdrawal, you should consult your doctor for guidance on how to safely discontinue use. Your doctor may recommend gradually reducing the dosage over a period of several weeks to allow the body to slowly adapt without it. Other medications may be prescribed on a short-term basis to alleviate withdrawal symptoms.

Getting Help: Treatment For Antidepressant Abuse Or Addiction

Though antidepressants are not known to cause physical dependence like other substances, some individuals may develop psychological dependence on the drug. Treatment for abuse or addiction may be required in cases of antidepressant misuse to help individuals learn to live without them and to prevent uncomfortable withdrawal symptoms. Antidepressant abuse can include but is not limited to taking higher doses than prescribed or using antidepressants in conjunction with other substances like alcohol and opiates.

Treatment can help reduce severe side effects of withdrawal, providing an easier and supervised transition to life without antidepressants. Therapeutic interventions can equip individuals with the tools they need to combat depression without the use of medication.