How long for an increased dose of antidepressant to work?

In this article, we are going to answer the following question: How long for an increased dose of antidepressant to work? We will discuss the phenomenon of antidepressant tolerance and addiction. We will also describe the 4 types of antidepressants and their side effects. 

How long for an increased dose of antidepressant to work?

People often argue as to why does it take so long for antidepressants to work? Even an increased dose of antidepressant to work may take up to several weeks.  The antidepressant dose is established by the doctor. As a general rule, the lowest dose that has been shown to be effective is prescribed and slowly increased every three to four weeks. The dose increase depends on the response and the presence or not of side effects.

The duration of antidepressant treatment must be agreed with the prescribing doctor. The recommendation of the mental health professional will depend on the number of episodes, the duration of the last episode, the time until recovery, and the presence of other mental health problems or medical illnesses. There is no mathematical formula that calculates time, but it is important that the psychiatrist inform the patient of the risks and benefits in their particular case.

Antidepressants or antidepressant medication are a group of drugs that can improve mood in depressed people. Antidepressants, in addition to treating depression, can treat other psychiatric disorders, especially anxiety disorders. These medications are not euphoric. Therefore, they will not produce euphoria in people with a normal state of mind.

Antidepressants don’t usually interfere with a person’s daily performance. They do not produce negative effects on concentration, memory, or the ability to relate or drive. However, depression can produce these symptoms. Therefore, antidepressants could potentially improve these symptoms by globally improving mood.

Antidepressant dependence

Antidepressants do not produce tolerance or dependence. Therefore, people who take antidepressants do not get used to their effect (tolerance) over time, nor does it lose efficacy over time. Antidepressants don’t produce dependency either. That is, not by starting to take antidepressants, it will be necessary to continue taking them.

Many people are afraid to start taking antidepressants because they have been told that once you start you cannot stop. This statement is false. People who take antidepressants do so because they need it. The time they are going to take the antidepressant is going to be what they need. 

Some people may be taking the antidepressant for less than a year, while others will need years of treatment. This difference in treatment duration depends on the number of depressive episodes, severity and duration of episodes, recovery time, and a family history of depression. In any case, it would be a doctor’s decision to agree with the patient.

People who feel bad when they stop taking the antidepressant can be for two main reasons. The difference will be in the time that passes from stopping the antidepressant until they start to feel bad. If two or three days pass, it is most likely a withdrawal syndrome. If the discomfort appears two weeks after you have withdrawn the antidepressant, it may be a relapse.

The phenomenon of tolerance in the use of antidepressants

Antidepressant tolerance is a phenomenon that can be defined as the lack of response to treatment in patients who had previously responded to the prescribed treatment. This implies that a patient who has achieved remission of the depression, despite continuing to take the drug, has a high probability of having a new relapse. It is something that can occur in antidepressants that only have a mechanism of action.

The phenomenon of tolerance affects 25% of patients taking antidepressants with a single mechanism of action.

Keep in mind that up to 80 per cent of patients who have had a depressive episode will relapse despite taking treatment. Many of these cases have to do with the phenomenon of tolerance.

What are the biological explanations for tolerance?

It is hypothesized that it has to do with neuroadaptation mechanisms: SSRI antidepressants, for example, have the function of increasing serotonin in different parts of the brain. 

Keeping serotonin elevated for a long time triggers mechanisms at the brain level that try to reduce that serotonin since this phenomenon is classified as “abnormal” by the central nervous system. Therefore, you administer a drug looking for an effect, but the brain develops mechanisms that go against that effect of the drug.

Increasing the dose of antidepressant

Increasing the dose only makes sense if the antidepressant drug has several mechanisms of action that depend on the dose since the increase in dose can activate new mechanisms of action that avoid the tolerance effect. However, most antidepressants have only one mechanism of action, so increasing the dose has little evidence of efficacy for most drugs.

Increasing the dose also implies more side effects that can lead to the abandonment of drugs with a single mechanism of action.

According to the latest studies, the low and medium doses of most antidepressants are the optimal doses, since the high doses do not achieve efficacy in many patients and carry more side effects that imply a risk of abandonment of treatment.

Types of antidepressants

As its name suggests, antidepressants are used to combat the symptoms of depression when it is moderate or deep, which can be many and very varied, such as prolonged sadness, loss of interest in life, inability to enjoy life, and lack of concentration or insomnia among many others.

Antidepressants are also indicated in other types of mood disorders such as severe anxiety and panic attacks, obsessive-compulsive disorder, chronic pain, eating disorders and post-traumatic stress disorder.

There are almost 30 types of antidepressants, but, according to the American Psychiatric Society, they can be classified into four types:

• SSRI (Selective Serotonin Reuptake Inhibitors)

They are the most widely used and the ones that are usually prescribed first because they are the ones that produce the least side effects. They work by inhibiting the reabsorption of serotonin, without affecting other neurotransmitters. Among these antidepressants, we find fluoxetine (the famous Prozac) and others like paroxetine, sertraline or citalopram.

• SNRI (Selective Serotonin and Norepinephrine Reuptake Inhibitors)

In addition to inhibiting the reuptake of serotonin, they also act on norepinephrine, preventing its reuptake. Some examples are duloxetine, venlafaxine, or desvenlafaxine.

• Tricyclics. They act very similar to the previous two but can affect other neurotransmitters, causing more side effects. Since the previous two appeared, they are used much less, just in case the previous ones do not work and in severe cases of depression.

• MAOIs (Monoamine oxidase inhibitors). They are the least used because of the serious side effects they can produce, more even than tricyclics, and because they interact with many drugs, so they are only used in the most severe and resistant cases. They work by blocking the effects of monoamine oxidase, an enzyme that breaks down serotonin, epinephrine, and dopamine.

Depending on each patient, the symptoms and disorders they suffer and their circumstances, the psychiatrist will recommend one or the other, since each person responds differently to antidepressants.

What side effects do they have?

Antidepressants do not cause as much dependency as anxiolytics, mainly because their effects are not immediate. Even so, it is never recommended to leave them without a prescription or suddenly, as they can produce symptoms similar to that of withdrawal syndrome, such as anxiety, dizziness, stomach upset and flu-like symptoms. 

Also, during treatment, especially at the beginning, there may be side effects, which will depend on the type of antidepressant taken.

SSRIs and SNRIs, the most common types, can produce:

• Dizziness and anguish
• Sexual dysfunction
• Memory problems
• Urination problems
• Irritability
• Weight changes
• Increased blood pressure
• In severe cases, suicidal thoughts, although no increase in attempts.

In the case of tricyclics, the effects are more frequent and serious:

• Tremors
• Dry mouth
• Increased heart rate
• Drowsiness
• Weight gain
• Dizziness and disorientation
• Sexual dysfunction

MAOIs, very little prescribed today, are also those that produce more unwanted effects:

• Confusion and difficulty concentrating
• Dizziness, fainting
• Constipation
• Sexual dysfunction
• They can interact with foods rich in tyramine, such as walnuts, some fish and meat, and cheeses …
• Hypertension

Both tricyclics and MAOIs are very dangerous in cases of overdose.

FAQ for How long for increased dose of antidepressant to work

Why does it take so long for antidepressants to work?

It takes so long for antidepressants to work because of their mechanism of affecting one’s nervous system. The drugs used to combat depression are (SSRIs), which means selective serotonin reuptake inhibitors.  Generally, when you start this drug treatment, it takes several days or even weeks to take effect and this is often a cause of frustration and despair for some people. 

Is it possible for antidepressants to work right away?

No, it is not possible for antidepressants to work right away. Most of them take between 1 to 4 weeks to start working. You have to be patient and combine the treatment with psychotherapy methods. 

Why do antidepressants make you feel worse before better?

Antidepressants make you feel worse before better because the drug’s side effects occur before your depression symptoms can improve. You have to have a lot of patience with the treatment for depression.

Will antidepressants make me happy?

Antidepressants will not make you extremely happy, but they will help relieve the symptoms of depression and associated anxiety. What happens with depression drugs is that they prevent the neuron from picking up again the serotonin found in the synaptic space to increase the amount of serotonin between the neurons themselves. 

Conclusions

In this article, we answered the following question: How long for an increased dose of antidepressant to work? We discussed the phenomenon of antidepressant tolerance and addiction. We also described the 4 types of antidepressants and their side effects. 

Antidepressants do not produce tolerance or dependence. Therefore, people who take antidepressants do not get used to its effect (tolerance) over time, nor does it lose efficacy over time. Antidepressants don’t produce dependency either. That is, not by starting to take antidepressants, it will be necessary to continue taking them.

Increasing the dose only makes sense if the antidepressant drug has several mechanisms of action that depend on the dose since the increase in dose can activate new mechanisms of action that avoid the tolerance effect. However, most antidepressants have only one mechanism of action, so increasing the dose has little evidence of efficacy for most drugs.

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References

psychologytoday.com – Number One Reason SSRIs Take Four to Six Weeks to Work

Sciencedaily.com – Why do antidepressants take so long to work?

Cambridge.org – Why do antidepressants take so long to work? A cognitive neuropsychological model of antidepressant drug action

Sane.org – Antidepressant medication