The term antidepressant medication refers to several classes of drugs that are used for the treatment of clinical depression or major depressive disorder. They are also used in the treatment of the symptoms of depression that are associated with other psychiatric conditions, such as personality disorders, PTSD, and so forth. These medications have a number of other clinical uses that range from treating anxiety disorders and eating disorders to chronic pain and other conditions.
Major Classes of Antidepressant Medications
There are several major classes of antidepressant medications:
- Selective serotonin reuptake inhibitors
- Tricyclic antidepressants
- Monoamine oxidase inhibitors
- Atypical antidepressants
Selective Serotonin Reuptake Inhibitors (SSRIs)
SSRIs represent one of the newer classes of antidepressant medications and are also presently one of the most commonly prescribed of all prescription drugs. Although there is no definitive understanding of how any of the major types of antidepressant medications work, SSRIs are believed to work by blocking the reuptake mechanism for the neurotransmitter serotonin in the brain.
When the brain releases a neurotransmitter and the chemical messenger has completed its mission, the substance is either degraded or reabsorbed back into the neurons. The current theory regarding SSRIs is that they block the reuptake mechanism for serotonin, and this increases the amount of available serotonin in the system. This is believed to relieve the symptoms of depression.
SSRIs do not have significant clinical evidence to support the notion that they treat depression any better than other classes of antidepressants, such as tricylclic antidepressants; however, they have fewer and less severe side effect profiles than the other classes of antidepressant medications. Some commonly recognized SSRIs include:
There are other several other SSRI medications on the market, and newer ones are being developed. Although they have a less severe side effect profile than other antidepressant drugs, SSRIs do have potential side effects. One side effect is the potential to increase suicidal thoughts. Other side effects include:
- Restlessness and anxiety
- Decreased sex drive
- Drowsiness or fatigue
- Weight gain or weight loss
- Dry mouth
In some people, these drugs may increase feelings of hostility or agitation. They may increase the risk of falls, bone loss, and bone fractures in elderly individuals.
Tricyclic antidepressants represent a class of antidepressants that have a very broad mechanism of action compared to the SSRI medications. These medications were developed in an effort to deal with the potential serious side effects of monoamine oxidase inhibitors (see below).
These medications block the reuptake mechanism for the neurotransmitters serotonin, norepinephrine, and partially for the neurotransmitter dopamine. While their effects on the symptoms of depression are generally equivalent to SSRIs, they have a much broader and more severe side effect profile. Due to their side effects, most physicians prefer to prescribe SSRIs in place of tricyclic antidepressants.
Some of the side effects attributed to these drugs include:
- Abnormal heart rhythms
- Increased heart rate
- Difficulty urinating
- Dry mouth
- Problems with vision
- Loss of sex drive
- Weight gain
Some of the more common tricyclic antidepressants include:
Monoamine Oxidase Inhibitors (MAOIs)
MAOIs are the oldest of the major classes of antidepressant medications. MAOIs interrupt the chemical breakdown of neurotransmitters in the brain, and this is believed to be their action of efficacy regarding the treatment of depression. These medications are no longer the frontline treatment for depression, and they are used sparingly.
MAOIs have severe interactions with certain types of foods, beverages, and other medications that contain the amino acid tyramine. These interactions can lead to dangerous increases in blood pressure and may facilitate a stroke or heart attack. Thus, people taking these medications need to pay strict attention to their diet.
Other side effects of MAOIs include:
- Weight gain
- Sexual problems
Some of the more common MAOIs include:
Atypical Antidepressant Medications
There are several other antidepressant medications, some newer and some older, that target the reuptake of serotonin and other neurotransmitters, or neurotransmitters other than serotonin. Some refer to these as atypical antidepressant medications, because they do not fit into any of the above classes. For example, Cymbalta, Remeron, and Effexor are termed SNRIs (selective norepinephrine and serotonin reuptake inhibitors).
Welbutrin is a medication that blocks the reuptake of the neurotransmitters norepinephrine and dopamine, and it is less likely to cause sexual dysfunction as a side effect. Welbutrin also has the property of increasing energy levels and therefore may be effective for types of depression where lethargy and sleepiness are major concerns. The side effect profiles for these drugs are specific to the drug.
Is It Possible to Become Addicted to Antidepressant Medications?
This is an interesting question. Before discussing the addictive potential of antidepressant medications a very important distinction must be made.
Addiction and Physical Dependence
The terms addiction and dependence are often used interchangeably. At one time, the term substance dependence was a clinical term used in place of the “outdated” term addiction. Today, the proper diagnostic phrase to refer to what many think of as an addiction is substance use disorder. Clinical terminology is constantly evolving; however, there is an important distinction between the notion of physical dependence on a specific drug and being addicted to the drug.
Physical dependence to a drug implies that the person has developed both tolerance and withdrawal to the drug:
- Tolerance is a process that occurs when an individual must take stronger doses of the drug to achieve the same effect that occurred at lower doses. The process is a combination of physiological and psychological factors, but often considered to be a primarily physiological process.
- Withdrawal is the occurrence of symptoms resulting from the abrupt discontinuation of the drug or medication (or significant lowering of the dosage). These symptoms are typically uncomfortable and represent both physical and psychological effects.
What Is Addiction?
The term addiction is used to describe a chronic disorder that presents as the nonmedical use of a drug that leads to compulsive use despite experiencing harmful, potentially harmful, or negative consequences from using the drug. These consequences can be physical, cognitive, emotional, or relate to social factors such as one’s relationships, legal issues, and issues with one’s work.
Addiction may or may not include the symptoms of tolerance and withdrawal; depending on the drug used (the term addiction can also be used in conjunction with a particular activity that is engaged in on a compulsive level leads to the same type of negative consequences).
Physical dependence by definition requires a person to display both tolerance and withdrawal, whereas addiction can occur in the absence of either of these or both of these, as well as in the presence of both tolerance and withdrawal. Thus, the symptoms of tolerance and withdrawal can occur during an addiction, but they are neither necessary nor sufficient to diagnose someone with an addiction.
For instance, there are a large number of patients suffering from chronic pain from a number of different conditions who are prescribed very potent narcotic medications for pain control. Many of these patients take these medications for quite some time and develop a physical dependence on the medication; however, they may not meet the criteria for substance use disorders/addiction (compulsive use, loss of control, negative consequences, etc.).
The development of tolerance to antidepressant medications does not appear to be widely debated and does most likely occur, at least in a proportion of people taking them. However, the notion of actually experiencing withdrawal symptoms from discontinuing antidepressant medications is a bit more controversial. .
Having made the distinction between physical dependence and addiction, it is now possible to discuss the question if someone can become addicted to antidepressant medications.
Can a Person Become Physically Dependent on Antidepressant Medications?
This topic is of some debate. In general, the medical community, ignoring the clinical definitions of substance use disorder and the strict definitions of tolerance and withdrawal, emphatically states that one cannot become addicted to antidepressant medications. For example, look at the below quote from the website WebMD:
“When antidepressants that affect the brain chemical serotonin are suddenly stopped, the body may respond with physical and emotional symptoms caused by the sudden absence of increased serotonin levels that occur while taking the antidepressant. These symptoms are not technically the same thing as physical ‘withdrawal’ from a drug. Physiological withdrawal happens when someone is taking a drug that can be addictive.”
The article goes on to explain that what occurs when people abruptly stop taking their antidepressant medication is known as antidepressant discontinuation syndrome (ADS). This is a term used by some to describe the process that occurs in certain individuals who abruptly discontinue using antidepressants.
This writer finds it interesting that the medical community tends to rationalize the inconsistencies in their policies and definitions. It is quite obvious that for some individuals, long-term use of antidepressant medications results in a mild form of physical dependence, even if there is no abuse of the drug. Moreover, some in the medical community ignore the differentiation that was made some time ago in the clinical diagnostic criteria between physical dependence and the clinical syndrome of substance use disorders/addiction. A very informative article in the journal Advances in Psychiatric Treatment published in 2007 addresses these issues in more detail.
Symptoms of ADS or Withdrawal from Antidepressant Medications
There is a set of symptoms that sometimes appear in individuals who abruptly discontinue using their antidepressant medication (ADS or withdrawal). It becomes purely a matter of semantics regarding which term is used; however, both terms essentially describe the same set of potential symptoms that occur under the same set of conditions.
It is probably more accurate to describe the symptoms that occur from abrupt discontinuation of antidepressant medications as a mild withdrawal syndrome in order to remain consistent with the notions of physical dependence, addiction, drug abuse, and so forth. The symptoms that are most often associated with withdrawal from antidepressant medications (or ADS if you prefer that term) include:
- Depression related symptoms (e.g., mood changes, lethargy, etc.)
- Vivid dreams
- Flu-like symptoms, such muscle ache and chills
In some cases, more serious symptoms such as hallucinations are reported. These symptoms do not appear to occur in everyone who abruptly discontinues their antidepressant medications. The symptoms appear more common with discontinuation of antidepressants that affect the neurotransmitter serotonin.
Factors Affecting Withdrawal from a Drug
Whether the symptoms occurring with abrupt discontinuation of the drug represent an actual withdrawal syndrome or whether they are termed as a discontinuation syndrome, there are factors that typically influence the length and severity of the types of symptoms one experiences following discontinuation. Important considerations include:
- The type of drug: Some drugs have no effects associated with their abrupt discontinuation and some do.
- Length of use: Typically, the probability of experiencing withdrawal-like symptoms increases the longer one takes a drug.
- Dosage level: Taking higher dosages of a drug results in higher probabilities of experiencing symptoms when one stops taking it.
- Speed of discontinuation of use: When one stops taking a drug altogether suddenly, one will have a higher probability of experiencing symptoms associated with withdrawal as opposed to slowly tapering down the dosage as one discontinues taking it.
- Individual variability: Different people have different reactions to drugs.
Can Antidepressant Medications Be Abused?
When anyone uses a drug outside of reasons for its intended use, the drug is being abused. Thus, it is a safe bet that most any drug can potentially be abused. A 2014 review published in the journal Substance Abuse and Rehabilitation found some evidence that antidepressant medications were abused by a very small number of people, most of whom had other substance use disorder issues with other drugs and abused antidepressant medications in combination with other drugs of abuse. The actual prevalence of antidepressant medication abuse is unknown at this time; however, it is likely relatively rare.
The potential of addiction still remains a question of some debate. Certainly, some individuals may develop a strong psychological attachment to their antidepressant medication that is strengthened when they experience withdrawal symptoms as a result of trying to stop using it. Moreover, it is also quite probable that some of the symptoms that are experienced when a person discontinues using an antidepressant medication are misinterpreted as being:
- The return of depression
- Indicative of some other psychiatric problem
- The result of some other medical condition
- The effects of some other medication
Given the current state of knowledge regarding the effects that occur when some people attempt to discontinue their antidepressant medication, the current definition of substance use disorders, and an understanding of the differentiation between the notion of physical dependence and addiction/substance use disorder, the probability of a person developing an addiction to antidepressant medication is rare, if it occurs at all.
Some individuals may become psychologically dependent on their antidepressant medications; however, this dependence does not represent the type of severe addiction observed with drugs of abuse such as alcohol, opiate drugs like heroin, cocaine, and so forth.
How to Safely Stop Using Antidepressant Medications
The recommended procedure to discontinue use of any antidepressant medication is to do so under the supervision of a physician such as a psychiatrist. This will allow the physician to gradually taper the dose down and result in a lower probability of the person experiencing significant and/or abrupt symptoms of discomfort that can occur when one experiences withdrawal-like symptoms from discontinuing medication. The physician can also prescribe other medications that can assist in the discontinuation processes or engage in other strategies to help make the process run more smoothly.
It is strongly recommended that a person does not abruptly stop using their antidepressant medication unless they are told to do so by a physician or unless that person is experiencing extreme discomfort that occurs very shortly after taking the medication (which may occur if the individual develops some level of allergic reaction to the medication). Even in the case where individuals stop taking a medication on their own because it appears to be producing serious side effects, it is strongly recommended that individuals immediately contact their physician and discuss the issue.