The term “depression” carries a variety of meanings. In everyday language, we might use it to describe feeling down or sad, but in a clinical context, it refers to a medical condition requiring treatment. When people casually say things like “I feel depressed today,” or “I’m down,” they are often talking about their mood, which is essentially an emotion. Most of the time, our mood is neutral, but it can range from joy to sadness. The closer we are to the latter, the more we might feel melancholic or depressed. Therefore, depression in everyday language can be both qualitative and quantitative, ranging from mild sadness to severe unhappiness.
Depression in Psychiatry
In clinical terms, depression can either be a single symptom, often short-lived, or a syndrome comprised of other enduring symptoms. People who report feeling depressed commonly describe a persistent sense of despair or a lack of interest and pleasure in life (anhedonia). This could manifest as frequent crying, lack of participation in activities they would usually enjoy, or other people observing that they seem depressed. Additional symptoms often accompany these feelings, including sleep and appetite disturbances that could be either too little or excessive. A weight change of at least 5% within a month is also common. People with clinically diagnosed depression might also complain about a near-daily lack of energy or fatigue, reduced concentration, and difficulty in making decisions. Patients may also feel agitated or, conversely, have slowed physical movements. Many have low self-esteem or excessive guilt, and may ruminate on their problems. Further complicating the situation, patients with comorbid conditions taking concurrent medications may also exhibit symptoms similar to depression, such as insomnia, weight loss, and fatigue.
The article explores the concept of depression in both its colloquial and clinical uses, noting that the experience and severity can vary widely.
How Common is Depression?
Major depressive disorder affects a significant portion of the population. Lifetime prevalence ranges from 10% to 25% among women and from 5% to 12% among men. These rates are consistent across different factors such as nationality, education, income, and family status. Major depression has a high mortality rate, with up to 15% of patients committing suicide. Additionally, patients over the age of 55 have a suicide rate that is four times higher than that of the general population. Patients with major depression also report more frequent physical pain and ailments, make more visits to doctors, and generally have decreased overall functionality.
Are There Other Coexisting Mental Disorders?
Other psychiatric conditions may coexist, such as dysthymia, in 10%–15% of patients with major depression (known as “double depression”). Anxiety disorders (e.g., panic disorder, obsessive-compulsive disorder), eating disorders (e.g., anorexia nervosa, bulimia), personality disorders (e.g., borderline personality disorder), and substance abuse disorders may also co-occur. Up to 25% of patients with chronic diseases like diabetes, heart attacks, strokes, and cancer may also develop major depression.
What is the Risk of Suicide?
It is crucial for clinicians to determine whether a patient is experiencing recurrent thoughts of death (not just the fear of death), passive suicidal ideation (i.e., thoughts of suicide without a specific plan or a preference for being dead over alive), or active suicidal ideation (i.e., a specific plan for suicide or a past attempt). The most dangerous time for suicidal patients is when they begin to feel more energized but still harbor suicidal thoughts. This period often occurs during the initial treatment and immediately after discharge for hospitalized patients. Approximately 50% of individuals who commit suicide have a prior diagnosis of depression. Early risk factors that heighten the danger in depressed patients include panic attacks, emotional distress, anhedonia, substance use, and persistent insomnia. Long-term risk factors include despair, suicidal ideation, and a history of previous attempts.
Are There Different Forms of Depression?
Depression comes in various subtypes. Melancholic depression is a specific form that doesn’t improve even temporarily. It worsens in the mornings and is associated with early wake-ups, a slowdown in physical movements, anxiety, significant weight loss, and excessive or unreasonable guilt. People with this type of depression are less likely to have a personality disorder or a specific risk factor that predisposes them to depression. Melancholic depression affects both genders equally and is often more severe and common in older individuals.
Atypical depression, on the other hand, is characterized by mood swings, where the mood improves in response to a genuinely or potentially positive event. It also includes significant weight gain or increased appetite, longer sleep duration, feelings of heaviness in the arms and legs, and a long-term pattern of sensitivity to interpersonal rejection, leading to significant functional impairment. Atypical depression is more commonly found in women, those with a younger age of onset, and those who show a more chronic course of the disease.
Depression can also manifest in women within the first four weeks of the postpartum period. Postpartum depression involves mood instability, potentially leading to suicidal ideation, obsessive thoughts of harming the newborn, lack of concentration, and motor agitation. Psychotic symptoms such as delusions concerning the baby may also be present.
Seasonal fluctuations in depression can also occur. Episodes usually begin in the fall or winter and may recur. Symptoms of seasonal depression include severe lack of energy, extended sleep duration, overeating, weight gain, and intense cravings for carbohydrates. Younger individuals, especially women, seem to be at higher risk for developing seasonal depression.
How Effective is the Treatment for Major Depression?
Between 60% and 80% of patients with major depression respond well to a single course of medication treatment, provided it is given at an adequate dosage and for a duration of at least six weeks. For the remaining patients, most experience at least some improvement. However, 10% to 15% of patients do not see significant improvement. For those who don’t fully respond to the initial medication, combining medications or switching to a different drug often proves effective. It’s worth noting that many patients considered “resistant” to treatment often have not received it in sufficient doses or for an adequate duration. Additionally, patients with co-occurring psychiatric disorders, such as personality disorders, tend to have lower response rates.
What Are the Chances of Recurrence?
The trajectory of recurring major depression varies among patients. Some experience isolated episodes with many years in between, while others have clusters of episodes, and yet others face an increasing number of episodes over time. Roughly half of the patients who experience one major depressive episode will have a second one. Those who have had two episodes have a 70% chance of experiencing a third. Furthermore, 5% to 10% of patients with a major depressive episode eventually show symptoms of a manic episode, indicating conditions like bipolar or manic-depressive disorder. Symptoms of a major depressive episode can develop within days or weeks, while early signs, such as anxiety and mild depressive symptoms, can last for weeks or even months. An untreated episode typically lasts for at least six months regardless of the age of onset. Most patients fully recover, but in 20% to 30% of cases, the recovery is only partial, and in 5% to 10%, the major depressive episode can last for 2 years or more.