Depression is an illness that affects nearly 280 million people worldwide. There are several types of depression, each with its own set of symptoms and recommended treatment methods. Therefore, overcoming depression requires understanding the type of depression you may be facing and getting the proper help.

1. Major Depressive Disorder

Major depressive disorder (MDD), also known as clinical depression, is characterized by a persistent feeling of sadness or emptiness lasting for at least two weeks. According to the World Health Organization, major depressive disorder is projected to rank first as the top burden of disease worldwide by 2030.

Symptoms of Major Depressive Disorder

This type of depression is more than just a case of the blues. It may severely obstruct your ability to function at work or school, enjoy activities that were once pleasurable, and maintain healthy personal relationships.

Other symptoms of MDD include:

  • Changes in appetite or weight
  • Insomnia or sleeping too much
  • Loss of interest in hobbies and activities
  • Trouble concentrating
  • Feeling hopeless, guilty, or worthless
  • Suicidal thoughts
  • Feeling agitated or restless

Major depressive disorder affects each person differently, so not everyone will experience all the symptoms listed above. However, having at least five of the above symptoms for at least two weeks is generally needed for your doctor to diagnose MDD.

2. Persistent Depressive Disorder

While this form of depression is not as severe as MDD, it may last for much longer, often years. Persistent depressive disorder (PDD), also known as dysthymia, is a type of depression that typically comes and goes over time. Symptoms of PDD generally do not disappear for more than two months at a time and may range in intensity from mild to severe. However, dysthymia is typically categorized as a mild form of depression with low moods lasting for at least two years. 

Symptoms of Persistent Depressive Disorder

Your symptoms may be similar to those of MDD, but the main differentiator is their severity. With PDD, your symptoms may not be as severe as with MDD, but they last for a much more extended period of time. Furthermore, episodes of major depression may coincide with periods of PDD. This is often referred to as a double depression.

Common symptoms of PDD include:

  • Trouble sleeping
  • Increased irritability and anger
  • Decreased appetite or overeating
  • Feelings of hopelessness
  • Avoiding social activities
  • Difficulty concentrating and staying motivated
  • Low self-esteem

Because the symptoms of persistent depressive disorder may go on for such a long time, many of those affected may not even realize they have a problem. It is not uncommon for those with the disorder to think of their symptoms as just a part of life. As a result, PDD is often underdiagnosed and left untreated. If you think you may be suffering from PDD, it is essential to reach out to your doctor for help.

3. Manic Depression

Manic depression, also known as bipolar disorder, is a type of depression that is characterized by extreme mood swings. These mood swings may range from feelings of extreme irritability or energized behaviors known as manic episodes to feeling “down” or depressed.

A hypomanic episode is a less severe form of a manic episode and falls somewhere in between normal moods and full-blown mania. Those with manic depression may often still complete day-to-day tasks during hypomanic episodes. However, the depressive episodes may be so severe they interfere with work, school, and social activities.

Symptoms of Manic Depression

Depending on whether you are experiencing a manic or depressive episode, the symptoms of manic depression may vary. Those with the disorder often have periods of intense emotion and behaviors called mood episodes. Many of those affected may experience a mood episode without even realizing it. During a mood episode, your symptoms may last for most of the day, anywhere from a few days to several weeks.

Symptoms of a Manic Episode

During a manic episode, you may:

  • Have more energy than usual
  • Be more talkative than usual
  • Feel like your thoughts are racing
  • Be impulsive
  • Engage in risky behaviors
  • Have difficulty sleeping
  • Feel more egoistic

Symptoms of a Depressive Episode

On the other hand, during a depressive episode, you may:

  • Have difficulty making decisions
  • Feel hopeless, empty, worried, or sad
  • Have trouble sleeping or sleep too much
  • Lose interest in activities you once enjoyed
  • Have thoughts of death or suicide
  • Experience an increased appetite and weight gain

Bipolar disorder is a life-long condition with mood episodes recurring over time. While some may not have any symptoms between episodes, others may have what is known as residual symptoms. These are milder versions of full-blown manic or depressive episodes.

4. Seasonal Affective Disorder (SAD)

As the name suggests, seasonal affective disorder (SAD) is a type of depression that occurs during certain seasons. The symptoms of SAD usually start in the late fall and continue into the winter months when there is less sunlight. However, in some cases, the symptoms may begin in the spring or summer. This is referred to as summer-pattern SAD.

While the exact cause of SAD is unknown, it is believed to be related to the serotonin levels in the brain. Serotonin is a neurotransmitter that plays a role in mood regulation. The reduced sunlight during the winter months may cause a decrease in serotonin levels, which may lead to the development of SAD.

Symptoms of Seasonal Affective Disorder

The symptoms of seasonal affective disorder span about four to five months and usually start around the same time each year. The most common symptoms include:

  • Hypersomnia (sleeping too much)
  • Overeating and weight gain
  • Social withdrawal
  • Insomnia
  • Restlessness
  • Anxiety
  • Episodes of violent outbursts

While these are a few of the common symptoms seen in those with SAD, not everyone will experience all of them. Each person experiences the disorder differently. It is also important to note that summer-pattern SAD usually presents symptoms opposite to winter-pattern SAD. For example, instead of hypersomnia, a symptom commonly associated with winter-pattern SAD, those with summer-pattern SAD may have insomnia. 

5. Psychotic Depression

Psychotic depression is a subtype of major depressive disorder and is characterized by the presence of psychosis. Psychosis is a condition in which you lose touch with reality. During a psychotic episode, you may have hallucinations or delusions.

Hallucinations are false perceptions of things that are not actually there. Delusions are false beliefs that you hold despite evidence to the contrary. While these symptoms are also seen in those with schizophrenia, they are different in that delusions and hallucinations are usually related to the theme of depression.

Symptoms of Psychotic Depression

For those with psychotic depression, thoughts of death or suicide are not uncommon. You may also hear voices that tell you to hurt yourself or others. Delusions usually involve themes of guilt, worthlessness, or illness.

Other symptoms of psychotic depression include:

  • Anxiety
  • Agitation
  • Oversleeping or insomnia
  • Hypochondria
  • Physical immobility

It is not uncommon for those with psychotic depression to feel ashamed or embarrassed by their symptoms. As a result, many people do not seek treatment. This makes psychotic depression particularly difficult to diagnose. If you or someone you know is exhibiting signs of psychotic depression, it is important to seek professional help.

6. Postpartum Depression

Having a baby may bring on a range of emotions, from happiness and excitement to sadness and anxiety. For some women, these feelings are so intense they develop postpartum depression (PPD). This type of depression may occur after childbirth and is thought to be caused by a sudden hormone change.

Most new mothers experience some form of the “baby blues” after childbirth. This normal and temporary condition usually goes away within two weeks and begins within the first few days after delivery. However, PPD is different because it is more severe and lasts longer than baby blues.

Symptoms of Postpartum Depression

Postpartum depression may occur during pregnancy, after the first few weeks post-delivery, or even up to a year after the baby is born. The following symptoms may be so severe they hinder your ability to care for yourself or your baby.

The most common symptoms of PPD include:

  • Mood swings
  • Trouble bonding with your baby
  • Excessive worry or anxiety
  • Sadness or hopelessness
  • Anger or irritability
  • Panic attacks
  • Thoughts of harming yourself or your baby
  • Feeling like you’re an unfit mother
  • Withdrawing from friends and family
  • Insomnia
  • Difficulty thinking clearly or making decisions

New mothers are not the only ones that need to be on the lookout for PPD. Postpartum depression may also occur in fathers. Known as paternal postpartum depression, this form of PPD has symptoms similar to those seen in mothers.

Furthermore, you should also be aware of postpartum psychosis. Although rare, postpartum psychosis is a severe form of PPD that may lead to hallucinations, delusions, and thoughts of harming yourself or your baby. If you think you may be dealing with any form of PPD, it is crucial to seek professional help.

7. Premenstrual Dysphoric Disorder

Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome (PMS). PMS is a group of symptoms that occur in the days leading up to a woman’s period. For most women, these symptoms are mild and include bloating, fatigue, and irritability. However, for some women, the symptoms are so severe they interfere with their daily lives.

Symptoms of PMDD

The symptoms of PMDD are similar to those of PMS, but they are more severe. PMDD is thought to be caused by a combination of hormonal and brain chemistry changes. The following symptoms may occur in the days leading up to your period and typically go away two to three days after your period starts.

Symptoms of PMDD include:

  • Pain in the muscles, pelvis, and breast
  • Mood swings
  • Panic attacks
  • Feelings of deep sadness, anxiety, or hopelessness
  • Insomnia
  • Food cravings or binge eating
  • Bloating
  • Low self-esteem
  • Trouble concentrating
  • Lost interest in activities you once enjoyed

These types of depression are just some of the many that exist. It’s important to remember that depression is a serious mental illness and should not be taken lightly. Finding the proper treatment is essential to managing your depression but is often easier said than done. If you think you may be dealing with depression, the first step is to seek professional help.

Look for Clinical Studies on Depression at Olympian Clinical Research

Olympian Clinical Research frequently hosts studies on depression. If you or a loved one is struggling with depression, monitor our list of enrolling studies to see if you qualify for one of our upcoming research opportunities.