Do Antidepressants Affect Intelligence?

Do Antidepressants Affect Intelligence

Are you about to start taking antidepressants and are worried about their impact on your intelligence? Perhaps you have heard antidepressants can affect your intelligence and want more information?

Or maybe you are curious and want to know more? Whatever your reason might be, we have the answer for you!

When it comes to antidepressants, there are lots of theories flying about their impact. Some of these are grounded in scientific research and evidence, others are not.

It can be tricky to sift through these and know what is real and what should be ignored. It leaves you overwhelmed, and unsure where to turn.

Well, no more! Today, we have all the answers you need. Keep reading to find out if antidepressants affect intelligence and everything else you need to know about them.

What Is Depression?

Before we dive in, let’s take a quick look at what depression is. Depression is an emotional state characterized by persistent feelings of sadness or loss of interest in normal activities. Symptoms include:

  • Loss of appetite
  • Sleep Problems
  • Fatigue
  • Low energy
  • Depressed mood
  • Irritability
  • Trouble concentrating
  • Poor memory
  • Feeling tired
  • Social withdrawal
  • Appetite changes

Some people experience physical symptoms such as headaches, stomach aches, or sleep problems. People with depression may have thoughts about suicide. Depression can cause changes in behavior or thinking.

How Do Antidepressants Work To Treat Depression?

The body’s neurotransmitters (chemical messengers) play a role in how we feel and act. The brain produces serotonin, norepinephrine, and dopamine, which send signals through the nervous system.

When you have too little of these chemicals, your mood goes down and you become depressed.

These neurotransmitters regulate our emotions, behaviors, and ability to think clearly. Some medications increase levels of certain neurotransmitters so they will be more effective.

They also balance out brain chemistry which may be causing the depressive symptoms.

It might take several weeks of taking medication before you see an improvement in how you feel, and there may be side effects that come with taking antidepressants.

Are There Any Side Effects When Taking Antidepressants?

People generally tolerate antidepressant medicines well.

However, some side effects can occur. Common side effects include the following:

  • Drowsiness
  • Dry mouth
  • Headache
  • Trouble sleeping
  • Weight gain or loss
  • Agitation
  • Confusion
  • Constipation
  • Diarrhea
  • Nausea
  • Vomiting
  • Decreased sexual drive
  • Physical weakness
  • Dizziness
  • Sweating

Do Antidepressants Affect Intelligence?

Less common side effects include the following:

  • Heartburn
  • Blurred vision
  • Ringing in the ears
  • Rashes, joint pain
  • Changes in bowel habits
  • Chest pain, muscle ache
  • Numbness/tingling sensations
  • Change in perception of taste
  • Short-term memory impairment.

If these happen, you should tell your doctor immediately. If depression doesn’t improve with treatment, you can talk with your doctor about alternate treatments.

Types Of Antidepressants

Let’s take a look at the different types of antidepressants available.

  • Selective serotonin reuptake inhibitors (SSRIs): sertraline, fluoxetine, etc.
  • Tricyclic antidepressants (TCAs): tricyclics, also called tetracyclines: amitriptyline, clomipramine, trazodone, etc.
  • Serotonin-norepinephrine reuptake inhibitors (SNRIs) duloxetine, venlafaxine, etc.
  • Monoamine oxidase inhibitors or MAOIs: Phenelzine, Isocarboxazid, etc.
  • Other non-selective medications such as bupropion

TCAs were originally used for the treatment of depressive disorders; however, they have since been reported to be effective in treating a variety of types of neuropsychiatric disturbances including panic attacks, obsessive-compulsive disorder, alcohol abuse, eating disorders, insomnia, posttraumatic stress disorder, generalized anxiety, Tourette syndrome, attention deficit hyperactivity disorder, autism, Alzheimer’s disease, etc.

Research has indicated that the SSRIs may work better than the TCAs as an initial antidepressant.

However, because the side effects of these two groups overlap, it is usually possible for doctors to switch from one type of medication to another once symptoms start to subside.

Other forms of psychotherapy treatments such as cognitive behavioral therapy can be effective when combined with pharmacological interventions for major depressive episodes.

It is important to note, though, that no combination of psychotropic drugs has been demonstrated to be superior to any single drug alone.

Overview Of Intelligence

Intelligence refers to an individual’s capacity for reasoning, problem-solving, and other aspects of thinking.

Intelligence tests are designed to measure different aspects of intelligence, but most people refer only to general intelligence measured by IQ scores (also known as the “g factor”).

This g factor is one of the three main factors believed to explain human behavior. “General Intelligence” is the name given to the overall level of intelligence that we have at birth and throughout life.

To reach this level, all children must achieve early developmental milestones in each area of their brain’s development, although the speed at which they do so varies greatly between individuals.

Do Antidepressants Affect Intelligence?

What Factors Influence Intelligence?

Many factors affect how intelligent a person becomes—some genetic, some learned, and others acquired through experience and education.

In addition to innate talents, many people develop intellectual abilities simply by spending more time with their peers, improving their educational opportunities, reading, participating in hobbies and activities that interest them, communicating frequently with friends and family members, trying new things, and doing challenging work.

As children grow older, they begin to engage in social interaction with peers and teachers. Peer relationships play an important role in enhancing intellectual development because those who spend time together become better acquainted with one another.

They learn about each other’s strengths and weaknesses, and form friendships and support networks. Social experiences that occur later in life can also enhance intellectual growth.

How Do We Measure Intelligence?

There are multiple ways to measure intelligence. The kinds of IQ testing methods used today are based on research conducted in Scandinavia during the 1950s.

The results of these studies showed that IQ could be broken down into four components: Verbal skills, visual-spatial skills, working memory, and processing speed.

As our knowledge of brain function increased over time, researchers discovered additional components and began measuring them separately as well.

Thus, modern intelligence tests include many different elements, including verbal comprehension, nonverbal reasoning, working memory, perceptual organization, processing speed, spatial perception, inductive reasoning, divergent thinking, reading comprehension, arithmetic knowledge, numeracy, vocabulary, fluid reasoning, and social skills.

Although the exact mechanisms underlying intelligence remain uncertain, researchers believe that intelligence involves complex interactions among the various parts of the brain.

Some experts believe that mental ability depends upon the proper functioning of structures called neurotransmitters, while others suggest that intelligence is related to the size and shape of brain regions or even certain genes.

A popular theory suggests that genetics account for about half of variations in intelligence, while environmental influence accounts for the rest.

However, many psychologists question whether genetic explanations can adequately explain the wide range of differences observed across cultures.

Scientists also debate the extent to which changes in intelligence result from learning or the environment.

Researchers studying brain imaging data have found correlations between measures of cognitive performance and activity in specific brain regions.

More recently, some scientists have begun to study intelligence using functional magnetic resonance imaging (fMRI) techniques, which allow researchers to view blood flow directly in the brain.

Neuroscientists use fMRI to examine functions such as language production, emotional responses, movement control, attentional processes, decision making, recognition of faces and objects, and problem-solving.

The technique has been successful at identifying areas of the brain that become active when people perform particular tasks.

This information can then help neuroscientists understand what goes wrong when we suffer from diseases like Alzheimer’s disease, or depression.

It has also helped lead to new theories regarding autism spectrum disorders, ADHD, schizophrenia, obsessive-compulsive disorder, epilepsy, Tourette Syndrome, and other neurological conditions.

There is still much work to be done before fMRI techniques can be widely applied in clinical settings; for now, they are mainly useful for scientific investigations.

Do Antidepressants Affect Intelligence?

Research shows that depression causes the hippocampus (which is involved in learning and memory) to shrink.

Treatment with antidepressants can reverse these effects, which could, in turn, help a person to learn and remember as they would before they became mentally ill.

So, technically, the underlying mental health conditions if not treated could contribute to problems with learning and memory rather than antidepressants themselves.

Resolving depression also tends to increase a person’s ability to focus their attention and concentrate.

In some cases, the side-effects of antidepressants could affect a person’s ability to use their intellectual assets, however, untreated depression is far more harmful.

There is no significant evidence that depression or antidepressants directly affect IQ, however, untreated depression can severely impact the many mental facets needed to reach full intelligence potentials.


If you want to maintain your intellectual abilities, it is important to treat any mental health issues. Being intelligent means being able to solve problems and deal with challenges.

When you have a mental health condition like depression, your thoughts and behavior change and become negative, which can affect your ability to perform even simple tasks.

While depression doesn’t directly affect your level of intelligence, it affects your ability to use your intelligence appropriately.

This means that antidepressants inadvertently affect intelligence by helping you to recover from the mental illness which negatively impacts your abilities.

About our Author Michelle Landeros, LMFT license# 115130
Author: Michelle Landeros, LMFT

Michelle Landeros is a Licensed Marriage Family Therapist (LMFT). She is passionate about helping individuals, couples and families thrive.

Last updated: June 17, 2024