Major Depressive Disorder (MDD)

Jan 24, 2025

An Overview of Major Depressive Disorder (MDD)

Greetings my friend. Thanks for stopping by. Today I’d like to discuss a topic that is on the minds and in the hearts of millions of people in the United States and around the world. This is a medical condition that we are all aware of, which is Major Depression. Millions of people are currently diagnosed with depression and millions more are unaware that they may show signs of depression. They may think it’s normal and therefore not take any action to get evaluated for major depression. This is national health issue that is often stigmatized and oftentimes misunderstood. There is a lot of misinformation out there about depression, therefore, let’s take a dive in and look at what depression really is.

So, what is Depression? Depression can be broken down into 3 main parts:

Figure 1 - The Three Main Components of Depression

Depression is a broad term that is used to define a variety of mental conditions in the human body. Depression is an actual medical condition and is when a person has:

1) Depressed mood. They show signs of sadness, loss of appetite, feeling hopeless, discouraged at life and life circumstances, feeling like they are “down in the dumps,” feelings of “blahness.” Also, a person may have feelings of irritability and anxiousness in certain circumstances.

2) Lack of interest in pleasure. This is when a person losses interest in activities they previously found pleasure in such as events, hobbies, and other interesting-to-them activities. A person will feel like the things that previously interested them don't matter anymore and are not drawn to or attracted to them anymore. This lack of interest or lack of pleasure can result in a decreased interest in connecting with friends, family, spouses, or interests in the job, oftentimes resulting in withdrawal from social situations. Many people will also have a lower sexual drive when they are depressed, having a low libido because their entire body is in a state of depression.

3) Change in Weight or Appetite.  A depressed mind causes a lack of desire to move towards a direction and striving to achieve a task or goal. This depressed or low energy state of mind can result in a significant change in eating habits where a person either has no appetite and they notice a change in weight or they start to eat more foods than they usually would because they have lost a sense of control in their eating habits. A person may eat less or end up eating outside of their normal diet, such as having increased cravings for junk food and carbohydrates (sugary foods). A loss of control in eating habits can result in either significant weight gain or weight loss that is noticeable over a period of time (like over a month). A significant weight gain or weight loss may be a 5% change in body weight. For Example: a 160 lb person X 5% = 8 pounds weight loss or weight gain over the course of a month (can be over a shorter or greater time).

4) Loss of Energy or Fatigue. A depressed person will generally shows sign and symptoms of fatigue and low energy. This usually is seen as someone looking and feeling listless (lacking energy or enthusiasm), exhaustion, low mental drive, the need to rest during the day. Some people also feel a heaviness in their arms and legs. In addition, many people who have low energy due to depression will have a difficult time starting an activity or completing tasks and goals.

5) Disturbances in Sleep. One of the major symptoms of depressions is changes in sleeping habits. This is known as insomnia, which is the inability to have a restful sleep-wake cycle. With depression, insomnia can be found in the 3 major areas during sleep. These 3 areas are: starting, maintaining, and ending the sleep cycle. Depression leads to changes in these 3 main areas of sleeping:

  1. Difficulty falling asleep. Someone may complain of having thoughts and depressed feelings that get in the way of actually falling asleep.
  2. Staying asleep. A person may wake up in the middle of a sleep cycle and have difficulty falling back asleep.
  3. Waking up too soon. Someone can wake up earlier than they normally would and have a difficult time falling back asleep. For example, someone usually sleeps for 8 hours a night. They wake up at 4 am and can’t fall back asleep because feelings of worthlessness and hopelessness in life stalks their thoughts.

In addition, a depressed person can also sleep too much. Depression is a depressed and low energy state of the body. The body doesn’t seem to sleep restfully and a depressed person may end up sleeping longer than usual. This sleeping-in occurs often because someone just doesn’t see the “point in getting up” and getting on with their day and life in general. They seem to have lost the drive for living life and focus. They’ll stay in bed, sometimes remain there half-asleep and end up getting up very late. This seems to be a recurring cycle. When they do get up, they still feel tired and have low mental and physical stamina.

6) Memory Loss. Depression leads to forgetfulness and lapses in memory. A person forgets important things in their social and life circles and misses events they would normally go to. A low energy state of the mind generally results in focusing on the negative sides of life, which translates into a focus on negative things in general. Since the human mind is preoccupied with the negative and low energy state of the mind, other things (such as events, people, etc.) are tuned out of the mind and not “remembered or thought about.”

How Common is Depression?

Depression can occur for a short period of time and can stay for months and years. But how often is it and who gets depressed? The specific statistics on depression are not known, however, it’s believed that about 16.2% of the US population has had Major Depressive Disorder (MDD) sometime within their lifetime. About 6.6% of people have had major depression within the last 12 months of their life.

Major Depressive Disorder - severe depression that can be debilitating, impair life functioning, and last for months and years.

            It also seems that women are more likely to have depression than men. Women are 1.7-2.7 times more likely than men to have depression, with depression usually beginning during early adolescence and continuing into the mid-fifties. Adults between the age of 18-29 seem to experience the majority of depression events.

            Depression can occur at any age. It can start with children and end up in the elderly. Millions of elderly people have depression, sometimes even major depressive disorder. Oftentimes, depression in the elderly can be associated with them having other medical conditions as well (called comorbidities). In fact, in people between the age of 65-80, 20.4% of women and 9.6% of men have major depression (not just mild depression).

            Adolescents are at a high risk for depression. Major depression in adolescent children (12-18 years of age) is associated with substance abuse, suicide attempts, and death during those early adolescent years.

            Depression seems to affect everyone and anyone, but there are certain patterns that are noticeable for major depression. For example, about 8-18% of people with major depression have a first degree relative (such as a parent, brother, sister) with depression (compared with 5.6% of people WITHOUT depression having a first degree relative with depression). If that wasn’t bad enough, first degree relatives of someone with depression are 1.5 to 3 times more likely to develop depression! First degree relatives are persons like parents, paternal brothers and sisters.

Neurocognitive Depression

            Depression is an overall low energy state of the mind. Since the mind controls the body, the things that affect the mind will undoubtedly show up as signs and symptoms throughout the body. The symptoms of depression first start in the mind and show up in the body as signs of depression. These are known as the neurocognitive symptoms of depresson. Let’s break down the word ¨Neurocognitive.”

            Neuro – refers the nervous system of the mind and body. Nerves are the connections between the various parts of the brain and body, such as the brain connecting to the muscles in the legs to control movements. In the mind, there are nerve connections that connect the various parts of the brain together. These connections of nerves in the brain are known as neurons. Nerves are like electrical wires throughout the body that transmit electrical charges (electrical signals) through them, connecting one cell, tissue, or organ to another.

The human mind and the human brain are NOT the same thing. The human brain is the physical organ that contains the human mind. The human brain consists of cells and tissues that serve a specific function.

The human mind is the series of electrical connections of neurons that connect the various pieces of the human brain in order for them to perform their designated work. The human mind consists of the neuron network of electrical charges that powers the various parts of the brain and makes them work together to perform a function (ex. think thought, feel emotions, move the hands or feet, etc).

The brain can be metaphorically thought of as being like the computer hardware. The mind can be metaphorically thought of as being the operating system that runs the computer hardware.

The "cognitive" part of Neurocognitive are the various parts of the brain that are connected to each other when they talk to each other. In other words:

            Cognition = the various parts of the brain “talking” to each other in order to do a certain thing, such as move an arm or a leg, or thinking a thought, either consciously or subconsciously.

            The main problem that occurs with depression is that the neurons in the human mind are not working at optimal efficiency because the entire mind is in a low energy state. Since the human mind controls the human body, the human mind will “show its state” within the body. When a person has a more severe form of depression, these sign and symptoms in the body are seen as problems with:

  1. Concentration – cannot gather thoughts together effectively and put them to appropriate use.
  2. Attention – difficulty paying attention to tasks and situations in life (such as with family members, at work, social gatherings).
  3. Cognition – difficulty in shifting from one organized stream of thought to another organized stream of thought. Oftentimes, the thoughts may overall become “disorganized and chaotic.” This may contribute to problems with accurate judgement of things (lapses in sound judgment, which leads to poor decisions in life).
  4. Processing thoughts and ideas – thoughts come slower than usual, which is known as having a low psychomotor speed. The thoughts don’t come to your mind as quickly as you’d like.
  5. Memory – lapses in memory.
  6. Verbalizing – problems with saying words or coming up with new words to form sentences in a timely manner. It takes a while to think up new words to use in sentences and phrases.
  7. Socializing – seen as difficulty in picking up on emotional, verbal, and body gestures of other people to get an appropriate understanding of that other person’s thoughts, emotions, or body gestures. This is also known as being “socially slower” when someone has more severe depression.

Psychomotor Problems

            A person with depression may also have issues with body movements. These are seen as either agitation or retardation of body movements. With agitation, a person may be restless and fidgety, doing nonproductive and useless repetitive movements while having a feeling of anxiety and tension inside.

            On the other hand, someone may experiences a slowing down of body movements such as slower speech, body movements, or slower thinking.  They may not be very talkative, and when they are, the speech is usually more quiet and timid and appears to lack confidence. They may have a difficult time answering questions.

            The psychomotor problems associated with depression are less common in other forms of depression, usually showing up when someone has Major Depression.

The Spectrum of Depression

Depression is not a single symptom or event. The signs and symptoms of depression can increase or decrease over time, and can even go into remission (where you don’t feel depressed anymore for a while). Rather, depression is based on a continuum where it starts off as a mild form of depression and can grow into a more severe form of depression, known as Major Depressive Disorder (MDD), also known as Major Depression Disorder. In between the continuum of mild depression and MDD, a person can have a combination of various signs and symptoms of depression, and increasing in severity.

Figure 2 – The Spectrum of Depression

Looking at Figure 2 above, it’s been found that about 60% of people have the common symptoms of minor depression and Major Depression Disorder. The severity of symptoms first start with minor depression and progress towards Major Depression over time if the mind is not controlled. For many people, the continuum of mild to major depression symptoms falls somewhere in the spectrum of signs and symptoms of depression, which are:

  • Sadness, anxiety, irritability
  • Loss of concentration, thinking, decision making
  • Hopelessness, worthlessness, inappropriate guilt
  • Energy loss, body and mind fatigue

Signs of Depression - the things you can physically see such as low energy, looking down, looking sad, moving slower, etc.

Symptoms of Depression - the things you can't really see but "feel" inside. These are things such as negative thoughts, feeling down, mentally exhausted, maybe feel anxiety, etc.

The signs and symptoms of depression increase in severity as a person goes from minor depression to major depression along the depression spectrum. The intensity and duration of the common symptoms of depression will increase along the depression spectrum. Major depression is simply a more severe form of minor depression with more signs and symptoms.

There are many forms of major depression, and they are broken down into their various parts. The following is a list of the various known parts of major depression disorder, as defined by the DSM-5, which is the diagnostic manual for psychiatric illnesses. We won’t go into detail about these various types of depressive disorders as we’ll do this in later articles. We’re focusing on the main parts of depression in this article.

The Various Types of Major Depression Disorders:

  1. Anxiety – type of depression that consists of anxiety symptoms along with depression.  Also known as anxious depression. These are usually seen as excessive worrying, hand wringing, panic attacks, and focusing on a single negative theme in the mind (rumination). About 40-50% of depressive episodes can be considered anxious depression since symptoms of anxiety are present as well.
  2. Catatonic – depression plus the inability to move normally due to a psychiatric illness (catatonia).
  3. Atypical – depression symptoms mixed with a specific set of symptoms. Occurs in 15-50% of depressive episodes. These are symptoms of depression plus:
    • Depression +
      • Hypersomnia (excessive sleeping)
      • Increased appetite or weight gain (usually comes with eating more unhealthy foods).
      • React to pleasurable things such as feeling better when positive events occur.
      • Limbs feel heavy.
      • Overly sensitive to interpersonal rejection.
  4. Peripartum – depression that begins or persists during pregnancy or within 4 weeks of giving birth.
  5. Mixed FeaturesDepression PLUS at least 3 of the following features/symptoms:
    • Grandiosity – delusional disorder where you have an over-inflated view or sense of yourself in power, worth, knowledge, or identity. You think of yourself of being bigger than you really are.
    • A series of ideas or racing thoughts
    • Increased energy or do activities that are directed towards achieving a goal (possibly a negative goal)
    • Talk more than usual
    • Have a decreased need for sleep
    • Mood seems to be elevated or larger than life
    • Focus on pleasurable activities that are considered high risk and may have severe consequences (irresponsible and reckless activities)

Persons with mixed features of depression have a sense of mania or hypomania that is associated with their depression. Hypomania is a less severe form of mania.

6. Melancholic Depressiondepression plus:

  • Interrupted sleep
  • Loss of appetite
  • Variations in mood and energy
  • Anhedonia – (inability to gain pleasure from normally pleasurable activities)

7. Psychomotor agitation or retardation. The agitation would be a person who is depressed, restless and fidgety, doing nonproductive and useless repetitive movements while having a feeling of anxiety and tension inside. The retardation (slowing down) of depression would be slower body movements such as slower speech, slower body movements, or slower thinking.

8. Seasonal – depression that occurs during a specific period of time

9. Psychotic – this is depression plus persistent and more severe form of symptoms such as hallucinations and delusions.

Other Conditions that Commonly Go Along With Depression

Depression is a condition that is frequently found with other medical conditions. The trend is that about 69% of people who have major depressive disorder (severe depression) also have another medical condition as well. A person may have depression and also have, just to name a few:

  • Anxiety disorders – panic disorders, social anxiety disorder, generalized anxiety disorder, etc.
  • Phobias
  • Post traumatic stress disorder
  • Obsessive compulsive disorders
  • Attention deficit disorder
  • Substance abuse disorders
  • And many more.

In addition, it was found that within a 12 month period, about

  • 5% of people with diabetes
  • 20% of those with high blood pressure, heart attack, and stroke,
  • 4% of cancer patients
  • 41% of those who have problems with the joints (arthritis)
  • 33% of those with seasonal allergies, COPD, asthma
  • 4% of those with ulcers

have had major depression. This translates into millions of people in the US and many more worldwide that have major depression in addition to a psychiatric illness or medical condition.

Major depression is a problem in the United States and throughout the world. Millions of people are walking around attempting to function with depression and unfortunately, very few people actually seek medical help for depression and the other psychiatric medical conditions that are often found along with depression. There is treatment for depression, and it ranges from medication therapy to behavioral therapy. We won’t discuss how depression is treated with medications at this time, but we will take a close look at how it can be treated in a later article to follow as the list of medications to treat major depression is fairly extensive.

            In future articles, I’ll go into more detail about how depression works and how a person can learn to overcome depression by learning about what actually causes depression (the nuts and bolts, beyond what we talked about in this article) and how it can be alleviated through simple strategies.

Word of Caution

As a medical provider, I would encourage you to NEVER discontinue a medication prescribed by your doctor for depression or any other psychiatric illness because that can cause a tremendous problem such as withdrawal symptoms, even lead to suicidal thoughts or suicide attempts. Before starting, discontinuing, or modifying the dose of any medication, always consult your doctor first before considering this.

Conclusion

I hope you’ve enjoyed this article. I take great pleasure in sharing my knowledge with you and hope this article on depression has answered a few questions you’ve had in mind. If you have questions or comments about depression, please post them below this article in the comments section below. I'll read them. The more questions I get about a particular topic, the more likely I'll write another article that will help answer your questions. Looking forward to connecting you in the next health and wellness topic. Be great my friend.

Sergio, Pharmacist

References:

  1. Lyness, J., (2019). Unipolar depression in adults: Assessment and diagnosis. P. Roy-Byrne (Ed.), UpToDate. Retrieved July 13, 2019, from https://www.uptodate.com/contents/unipolar-depression-in-adults-assessment-and-diagnosis?search=depression&topicRef=14693&source=see_link
  2. Teter, C.J., Kando, J.C., Wells, B.G. (2017). Major Depressive Disorder. In G.R. Matzke, & B.G. Wells, & L.M. Posey (Eds), Pharmacotherapy. A Pathophysiologic Approach (pp. 1041-1045). 10th Edition. McGraw Hill.