Depression is a multifaceted mental health condition characterized by persistent feelings of sadness, hopelessness, and a lack of interest or pleasure in activities that were enjoyable in the past.
It can be classified into various types in psychology, each with distinct features, causes, and treatment approaches. Understanding these different categories can aid in making an accurate diagnosis and effective management.
Below are the primary types of depression recognized in the field:
- Major depressive disorder (MDD)
Also known simply as major depression, it’s characterized by a persistent feeling of sorrow or a lack of interest in outside stimuli.
To be diagnosed with MDD, symptoms must last for AT LEAST two weeks and represent a change from previous functioning. Common issues include:
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- Significant weight loss or gain.
- Insomnia or hypersomnia.
- Fatigue or loss of energy.
- Feelings of worthlessness or excessive guilt.
- Difficulty concentrating or making decisions.
- Recurrent thoughts of death or suicide.
- Persistent depressive disorder (PDD)
Formerly known as dysthymia, PDD involves a chronic form of depression with less severe symptoms than MDD but lasting for a longer period, typically at least two years.
Individuals may experience episodes of major depression along with periods of less severe symptoms, leading to a “double depression” scenario.
- Bipolar disorder
While primarily classified as a mood disorder, bipolar disorder involves episodes of depression alternating with periods of mania or hypomania.
The depressive episodes share similarities with MDD, including persistent sadness and loss of interest, but are distinguished by the presence of manic phases.
- Seasonal affective disorder (SAD)
SAD is a type of depression that occurs at a specific time of year, usually in the fall and winter months, when daylight hours are shorter.
Symptoms often improve with the arrival of spring and longer daylight periods. Light therapy is a common treatment for SAD that can provide some relief.
- Postpartum depression
This form of depression can occur in women after giving birth. It is more severe than the “baby blues” and can interfere with a mother’s ability to care for her child and handle daily tasks.
Common symptoms include extreme sadness, anxiety, exhaustion, and changes in sleeping or eating patterns.
- Psychotic depression
Includes symptoms of psychosis, such as delusions or hallucinations.
The psychotic symptoms typically have a depressive “theme,” such as intense feelings of guilt or worthlessness.
- Atypical depression
Atypical depression is characterized by mood reactivity (moods can improve in response to positive events) and specific symptoms like:
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- Increased appetite or weight gain.
- Excessive sleep.
- A heavy feeling in the limbs.
- Strong sensitivity to rejection.
- Premenstrual dysphoric disorder (PMDD)
PMDD is a severe form of premenstrual syndrome (PMS) with marked mood swings, irritability, depression, and anxiety occurring during the luteal phase of the menstrual cycle.
These symptoms significantly interfere with daily functioning.
- Disruptive mood dysregulation disorder (DMDD)
DMMD is primarily diagnosed in children and adolescents.
It’s characterized by chronic, severe irritability and frequent temper outbursts disproportionate to the seriousness of the situation at hand.
- Situational (adjustment) depression
This can happen in response to a specific, identifiable life event or stressor, such as the loss of a loved one, divorce, or job loss, for example.
Symptoms are similar to MDD but are directly related to the triggering event and typically improve once the individual adapts to the change.
- Double depression
Double depression means the manifestation of major depressive episodes on top of persistent depressive disorder (dysthymia).
Individuals experience chronic depressive symptoms with intermittent episodes of more severe depression.
- Agitated depression
Agitated depression is defined by harsh restlessness, agitation, and anxiety alongside typical depressive symptoms.
Afflicted individuals may exhibit extreme irritability, pacing, or even an inability to sit still.
There are a few other specialized forms and subtypes of depression that are less commonly discussed, but are still important within psychology and psychiatry.
These subtypes often overlap with broader categories but have specific features or occur under certain conditions:
- Treatment-resistant depression
This term refers to depression that does not respond adequately to standard treatments, such as antidepressants or psychotherapy.
Symptoms of treatment-resistant depression are the same as major depressive disorder, but the key feature is the lack of response to at least two different treatments.
Treatment often requires alternative treatments like electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), or ketamine infusions.
- Depression with catatonia
A rare form of depression that includes symptoms of catatonia, which is characterized by motor immobility or excessive purposeless movement.
Individuals may exhibit extreme physical rigidity, stupor, or repetitive movements, alongside the typical symptoms of depression.
Regularly treated with medications like benzodiazepines or ECT in more severe cases.
- Endogenous depression
This term was historically used to describe depression that arises from within the individual and is thought to have a biological or genetic cause, rather than being triggered by external stressors.
Symptoms are similar to those of a major depressive disorder but with a stronger focus on biological origins (e.g., disruptions in brain chemistry).
This term is less commonly used today, but it highlights depression, which is believed to have a more significant biological component.
- Exogenous (reactive) depression
In contrast to endogenous depression, exogenous depression is triggered by external events or stressors, such as the death of a loved one, job loss, or divorce.
Symptoms are comparable to major depressive disorder, but closely tied to a precise external cause.
Although these terms (endogenous vs. exogenous) are somewhat outdated, they still underscore the importance of understanding whether depression is more biologically driven or situational.
- Masked depression
A form of depression in which the typical symptoms (such as sadness and hopelessness) are hidden or “masked” by other complaints, often physical (somatic) symptoms.
Affected people may report physical symptoms like headaches, digestive issues, or chronic pain, rather than emotional distress. These individuals may not report feeling sad, but they experience depression through other symptoms.
Addressing both the physical complaints and underlying depression is crucial for remedying said illness.
- Substance-induced depressive disorder
This type of depression is directly related to the use of alcohol, drugs, or medications, or during withdrawal from them.
Depressive symptoms appear during or shortly after substance use and may include mood disturbances, irritability, and sadness.
The cure for this ailment focuses on stopping substance use and addressing the symptoms through therapy or medication.
- Depression due to a medical condition
This can happen when a medical illness or condition causes depressive symptoms.
Frequent medical conditions associated with depression include chronic illnesses such as cancer, heart disease, Parkinson’s disease, and thyroid disorders.
The symptoms can mimic those of other depressive disorders, but they are typically linked to the presence or progression of the medical condition.
- Perinatal depression
This type of depression occurs during pregnancy or within the first year after childbirth. Postpartum depression, which occurs after delivery, is a subset of perinatal depression.
Symptoms can include severe mood swings, anxiety, feelings of detachment from the baby, or guilt about parenthood.
Treatment typically involves therapy, support groups, and, in some cases, medication.
- Depression with mixed features
A subtype of depression where an individual experiences some symptoms of mania or hypomania (e.g., irritability, restlessness, increased energy) during a depressive episode, but not enough to qualify as bipolar disorder.
They regularly experience mood swings, agitation, and risk-taking behavior while going through symptoms of depression at the same time.
As we can see, these additional subtypes and special cases show the wide variability in how depressive symptoms can manifest.
