What is depression? Here are the symptoms and how it’s diagnosed

Depression – along with anxiety – has become a commonly used word in our contemporary lexicon. But despite its popularity, there might be less of an understanding of how the mental health community defines depression. In this article, I will outline the different types of depression. I hope this article will be useful in that it will bring into one place the different manifestations of depression, as they have been defined by the mental health community.

The most recent 5thedition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) has an entire subcategory called “Depressive Disorders,” that defines depression and its related disorders. The overarching feature of depressive disorders according to the DSM is “the presence of sad, emptiness, or irritable mood” (p. 155).

(Note: As I have mentioned in a previous article, while there are specific criteria for meeting the diagnosis of depression, as a psychologist, what I am most interested in is a patient’s internal sense of themselves, and whether or not this includes a sense that they are suffering from depression. In other words, I focus less on making sure people meet certain diagnostic criteria, and more on their personal, subjective experience of themselves and their lives.)

The classic presentation of depression is as “Major Depressive Disorder” (MDD), and as you will see from most of these disorders, the diagnosis of MDD begins with a specific time-period requirement: the individual must be experiencing depressed mood for at least 2-weeks. If someone has depressive symptoms, but does not meet this time-frame requirement, they might meet the diagnosis of “short-duration depressive disorder” or “recurrent brief depression” (which are listed in the DSM as under “Other Specified Depressive Disorders).

Major Depressive Disorder requires at least one of the symptoms of (1) depressed mood (for most of the day, and most days of the week) OR (2) loss of interest or pleasure (previously called anhedonia). After one these criteria are met, then the individual needs to have at least 3 additional symptoms in order to be diagnosed with MDD. They are:

1. Changes in body weight (weight gain or weight loss).

2. Changes in sleep (difficulty sleeping or over-sleeping).

3. Changes in motor function (slowing down of movements or feeling restless and agitated).

4. Fatigue or loss of energy nearly every day.

5. Feelings of worthlessness or excessive/inappropriate feelings of guilt.

6. Difficulty concentrating or thinking.

7. Recurrent thoughts of suicide or death.

Finally, these symptoms need to bother the individual (“cause distress”) and they need to have some effect on the individual’s daily life. (In other words, if the individual has these symptoms but they do not bother them, or negatively impact their life, then they would not meet the diagnosis of depression.) The DSM also states that one needs to rule out depression as a result of substances, menstrual cycle, grief, or medical conditions.

The next disorder, and very closely related to MDD is called“Persistent Depressive Disorder,” which used to be called “dysthymia.” This disorder is basically a chronic version of Major Depressive Disorder. In order to meet the diagnosis for Persistent Depressive Disorder, a person must be depressed for at least 2 years. So, you can take the exact criteria for Major Depressive Disorder that you see above, and just extend the time-frame. The DSM notes that the person cannot be without depressive symptoms for more than 2 months at a time. One needs to consider if it feels like you have had depressed mood, or a loss of interest and pleasure in activities, and if that experience has persisted continually for at least 2 years. If so, then you would meet the criteria for Persistent Depressive Disorder.

The DSM also lists the criteria for “Premenstrual Dysphoric Disorder.” This disorder involves changes in mood that occur in the “final weeks before menses,” that begin to go away after the onset of menses, and then are almost completely gone in the week following menses. One needs to at least experience mood swings, increased depression, increased irritability, or increased anxiety during this time. If one of those are met, then the individual needs at least meet another symptom of depression (as listed in the definition for MDD).

The next disorder in the depressive disorders category is “Substance/Medication-Induced Depressive Disorder.”We have found that substances (drugs or otherwise) and medication can cause someone to develop symptoms of depression. Some substances (in some individuals) can cause depression from taking them, withdrawing from them, or in coming into contact with them in some other way. If someone has been exposed to a substance which subsequently induces symptoms of depression, then the person would meet the criteria for this disorder instead of Major Depressive Disorder.

Also, some medical conditions can cause an individual to experience depression. Therefore, the last main diagnosis in the Depressive Disorders section of the DSM is “Depressive Disorder Due to Another Medical Condition.” This disorder is diagnosed when someone experiences depressed mood or loss of interest or pleasure as a “consequence” of another medical condition. For example, depression is commonly found as an associated symptom of Parkinson’s disease, hypothyroidism. Huntington disease, stroke, and traumatic brain injury.

Finally, it is important to note that the DSM lists some “specifiers” to this diagnostic category. Specifiers are additional information that are added on to a diagnosis in order to further clarify the nature of what is being diagnosed. These can help to elucidate and make more specific someone’s presentation. Important specifiers are:

1) With anxious distress– This specifier is used when someone’s unique experience of depression also includes feelings of anxiety.

2) With mixed features – When someone experiences mania (elation, grandiosity, increased energy) in conjunction with depression.

3) With melancholic features – This signifies that an individual is experiencing more severe depression, that with “profound despair,” and “near-complete absence of the capacity for pleasure.”

4) With peripartum onset – While the DSM doesn’t recognize “postpartum depression” as a distinct diagnosis, this specifier is used if an individual experiences depression during pregnancy, or in the 4 weeks after birth.

5) With seasonal pattern – This specifier, which been previously known as “Seasonal Affective Disorder,” is applied when there is a usual, regular onset of depression at certain times of the year. (Most commonly occurring in winter in colder environments.)

I hope this overview of depression has been informative. As a clinical psychologist I am skilled at treated depressive disorders. Whether it’s Major Depressive Disorder, one of its related disorders, or even feelings of depression that do not fully meet a diagnosis here, I have helped numerous people find relief from their symptoms, so that they can begin living more fulfilling lives.