Depressive Disorders

Depressive disorders are characterized by persistent feelings of sadness and worthlessness and a lack of desire to engage in formerly pleasurable activities. Depression is not a passing blue mood, which almost everyone experiences from time to time, but a complex mind/body illness that interferes with everyday functioning. It not only darkens one's outlook, it is commonly marked by sleep problems and changes in energy levels and appetite. It alters the structure and function of nerve cells so that it disrupts the way the brain processes information and interprets experience. Despite feelings of hopelessness and worthlessness, depression is a treatable condition. It can be treated with psychotherapy or medication, or a combination of both. 

Depression is a common condition in modern life. According to the National Institutes of Health, each year more than 16 million adults in the United States experience at least one episode of major depression. The likelihood that a person will develop depression at some point in life is approximately 10 percent. Prolonged social stress and major disruption of social ties are known risk factors for depression, and major negative life events such as loss of a loved one, or loss of a job, increase the subsequent risk of depression. Significant adversity early in life, such as separation from parents or parental neglect or abuse, may create vulnerability to major depression later in life by setting the nervous system to over-respond to stress. 

Definition

A depressive disorder is a condition that involves the body, mood, and thoughts. It disables motivation and interferes with normal functioning of daily life. It typically causes pain both to the person experiencing the mood disturbance and those who care about him or her.

A depressive disorder is not the same as a passing blue mood—by definition, the symptoms must be present for at least two weeks. Nor is it a sign of personal weakness or a condition that can be willed or wished away. Depression tends to be episodic, with bouts lasting weeks or months. Although symptoms tend to remit spontaneously over time, some form of treatment is important to reduce the likelihood of recurrent episodes. Appropriate treatment can help most people who suffer from depression.

Depressive disorders come in different forms, as is the case with other illnesses such as heart disease. Three of the most common types of depressive disorders are described here. However, all forms are marked by variation in the number of symptoms as well as their severity and persistence.

Major depressive disorder, or major depression, is manifested in a persistently sad mood accompanied by a number of other symptoms that interfere with the ability to work, study, sleep, eat, and enjoy once pleasurable activities. A disabling episode of depression may occur only once but more commonly occurs several times in a lifetime. Depression is more than a disorder only from the neck up. It also affects the function of many body systems. Researchers have established, for example, that immune function is often compromised in depressive states, and impaired immune function may in part underlie the link of depression to such other disorders as heart disease.

Dysthymic disorder, or persistent depressive disorder, also called dysthymia, involves symptoms of sad or down mood most days for most of the day over a long term (two years or longer) but  the depressed mood is not disabling, although it impairs functioning to some degree. Many people with dysthymia also experience major depressive episodes at some time in their lives.

Some forms of depressive disorder involve slight variation of features or develop under specific circumstances. 

Premenstrual dysphoric disorder manifests in the week before the onset of menses, subsides within days after onset of menstruation, and remits in the week after menstruation. According to the National Institutes of Health, 3 to 8 percent of women of reproductive age meet strict criteria for premenstrual dysphoric disorder.

Major depression with psychotic features, or psychotic depression, occurs when a severe depressive illness is accompanied by delusions and hallucinations, The psychotic features may be mood-congruent with the depression—that is, consistent with the depressive themes of personal inadequacy, guilt, nihilism, or death. Or the delusions and hallucinations may be mood-incongruent, not involving such depressive themes.

Major depression with postpartum onset, or postpartum depression, is diagnosed if a woman develops a major depressive episode during pregnancy or within four weeks after delivery. It is estimated that 3 to 6 percent of women experience postpartum depression.

Major depression with seasonal patterns, or seasonal affective disorder (SAD), is characterized by the onset of a depressive illness during particular times of the year. Typically, the depression develops during the winter months, when there is limited natural sunlight, and completely remits in the spring and summer months. In a minority of cases of major depression with seasonal patterns, the depression occurs during the summer months. SAD may be effectively treated with light therapy, but nearly half of those with SAD do not respond to light therapy alone. Antidepressant medication and psychotherapy can reduce SAD symptoms, either alone or in combination with light therapy.

Symptoms

The following signs and symptoms are catalogued by the DSM-5 as signifiers of major depressive disorder and at least five must be present during the extended period of low mood or loss of pleasure in once-enjoyable pursuits. Not everyone experiences every symptom, nor do people experience the same symptoms to the same degree. Symptoms may vary not only between individuals and but over time in the same individual. 

  • Persistent sad, anxious, or empty mood most of the day, most days
  • Feelings of worthlessness or excessive guilt
  • Loss of interest or pleasure in activities that were once enjoyed, including sex
  • Persistent loss of energy or fatigue
  • Difficulty thinking, concentrating, remembering, or making decisions
  • Insomnia, early morning awakening, or oversleeping (hypersomnia)
  • Significant change in appetite resulting in unintended weight loss or weight gain
  • Observable psychomotor agitation or restlessness, or psychomotor slowing 
  • Feelings of hopelessness or pessimism; recurrent thoughts of death or suicide, suicide attempts

Causes

There is no single cause of depression. Rather, evidence indicates it results from a combination of genetic, biologic, environmental, and psychological factors.

Research deploying brain-imaging—such as magnetic resonance imaging (MRI)—and other technologies shows that the brains of people who have depression look different than those of people without depression. The parts of the brain responsible for regulating mood, thinking, sleep, appetite, and behavior appear to function abnormally. But these changes do not reveal why the depression has occurred.

There are many pathways to depression. Genetic factors may play a complex role in setting the level of sensitivity to certain kinds of events, including the level of nervous system reactivity to stress and other challenges. Scientists know there is no single gene involved: many genes likely play a small role in contributing to vulnerability; acting together with environmental or other factors.

However, depression can occur in people without family histories of it as well. There is significant evidence that harsh early environments—especially experiences of severe adversity such as abuse or neglect in childhood—can create vulnerability to later depression by altering the sensitivity of the nervous system to distressing or threatening events.

Experiences of failure, rejection, social isolation, loss of a loved one, or frustration or disappointment in achieving relationship or any other life goal often precede an episode of depression. For that reason, many researchers regard the negative mood state of depression as a painful signal that basic psychological needs are not being met and that new strategies are needed. They also suggest that depression to some degree results from a lack of skills in processing negative negative feelings; some of the most effective therapies for depression teach what can be considered basic mental hygiene, cognitive and emotional tools for dealing with negative feelings. Trauma, which can overwhelm emotional processing mechanisms, is another common trigger for depressive episodes.

Depression in Women

Women experience depression about twice as often as men. Biological, life cycle, hormonal, and other factors—including experiential ones—unique to women may be linked to their higher depression rate. Researchers have shown that hormones directly affect brain regions that influence emotions and mood, and they are further exploring how hormone cycles can give rise to depressive states. Some women may be susceptible to the severe form of premenstrual syndrome called premenstrual dysphoric disorder (PMDD). Women are also vulnerable to depression after giving birth, when hormonal and physical changes, along with the new responsibility of caring for a helpless infant can be overwhelming. Many women also uniquely face such proven chronic stresses as juggling work and home responsibilities, single parenthood, domestic abuse, and caring for children and aging parents.

Ongoing research probes why some people faced with enormous challenges develop depression, while others with similar challenges do not.

Depression in Men

Millions of men in the U.S. and around the world also suffer the psychic pain of depression. Research and clinical evidence establish that while both women and men can develop the standard symptoms of depression, they often experience depression differently and may have different ways of coping with the symptoms. Men may be more willing to acknowledge fatigue, irritability, loss of interest in work or hobbies, and sleep disturbances rather than feelings of sadness, worthlessness, and excessive guilt. Some researchers question whether the standard definition of depression and the diagnostic tests based upon it adequately capture the condition as it occurs in men.

Depression can also affect the physical health in men differently from women. One study shows that, although depression is associated with an increased risk of coronary heart disease in both men and women, only men experience an elevated death rate.

Instead of acknowledging their feelings or seeking help in the form of appropriate treatment, men may turn to alcohol or drugs when they are distressed. They may also be angry, irritable, and, sometimes, violently abusive. Some men deal with emotional distress by throwing themselves compulsively into their work, attempting to hide their depression from themselves, family, and friends. Other men may respond to depression by engaging in reckless behavior, taking risks, and putting themselves in harm's way.

More than four times as many men as women die by suicide in the U.S., even though women make more suicide attempts during their lives. In light of the research indicating that suicide is often associated with depression, the high suicide rate among men may reflect the fact that many men with depression do not seek adequate diagnosis and treatment.

Encouragement and support from concerned family members can be lifesaving. In the workplace, employee assistance programs or worksite mental health programs can be particularly important n helping men understand depression as a real disorder that needs treatment.

Depression in the Elderly

Contrary to some popular thinking, depression is not a normal accompaniment to aging. On the contrary, older people tend to experience rising levels of satisfaction with their lives. However, when older adults do develop depression, the condition may be overlooked because it can manifest less in feelings of sadness or grief and more in irritability or general apathy or feelings of tiredness. Also, depression tends to affect memory, and in the elderly depression can show up as confusion or problems with attention. Aging brings many life changes that can be triggers for depression, including loss of a loved one, loss of employment and sense of purpose, loss of robustness or good health. 

In addition, medical conditions that occur more frequently with age, such as heart disease, stroke, and cancer, may cause depressive symptoms. Or the medications used for such conditions may carry side effects that contribute to depression.

There is a type of depression that develops in late life, known as vascular depression, sometimes also called arteriosclerotic depression or subcortical ischemic depression. It results from cerebrovascular damage that occurs with cardiovascular disease. Brain-imaging studies show  that areas of blood vessel damage restrict blood flow to regions of the brain involved in emotion and mood regulation or to the brain's white matter. Those who develop vascular depression often have a history of hypertension, or high blood pressure. Vascular depression may manifest in paranoia, aggressive tendencies, or apathy and slowing of movement. There are deficits in executive function. Diagnosis may involve magnetic resonance imaging (MRI) to detect vascular pathology in specific parts of the brain. Vascular depression tends not to respond to antidepressant medication; instead, the first line of approach may be forms of psychosocial support and/or cognitive behavioral therapy.

The majority of older adults with depression improve when they receive treatment with psychotherapy, antidepressant medication, or a combination of the two. Research has shown that psychotherapy alone can be effective in prolonging periods free of depression.

Treatment

Depression, even in the most severe cases, is a highly treatable disorder. The sooner treatment begins, the more effective it is and the greater the likelihood that recurrence can be prevented.

Appropriate treatment for depression starts with a physical examination by a physician. A number of medications, as well as some medical conditions, including viral infections and thyroid disorder, can cause depression-like symptoms and must be ruled out. Once a physical cause of depression is ruled out, a psychological evaluation can be conducted, either by the examining physician or via referral to a mental health professional.

An evaluation should include a detailed inquiry into the history and nature of current symptoms and prior episodes and their management as well as any family history of depression and its treatment. From this information, the severity of current symptoms can be rated; this information serves as a baseline for measuring improvement over time and guides the course of treatment.

Once diagnosed, depression can be treated with psychotherapy, medication, or a combination of both. Medication may help reduce symptoms while psychotherapy addresses the negative thoughts, feelings, and beliefs that give rise to distress and that need to be managed in more productive ways.

Psychotherapies

For mild to moderate depression, psychotherapy is generally considered the best treatment option. Psychotherapy is important in helping patients develop strategies for dealing with the situations that give rise to depression and to effectively manage the negative thoughts and feelings that mark t he distress. Both cognitive-behavioral therapy (CBT), and interpersonal therapy (IPT) have been widely tested and shown to be effective in treating depression. By teaching new ways of thinking and behaving, CBT gives people skills to disarm negative styles of thinking and behaving. IPT helps people understand and work through troubled personal relationships that may cause or exacerbate their depression.

Studies have indicated that for adolescents, a combination of medication and psychotherapy may be the most effective approach to treating major depression and reducing the likelihood for recurrence. Similarly, a study examining depression treatment among older adults found that patients who responded to initial treatment of medication and IPT were less likely to have recurring depression if they continued their combination treatment for at least two years.

Medications

Antidepressants target various neurochemicals—notably serotonin, norepinephrine, and dopamine—known to be involved in the relay of signals through various brain circuits. Nevertheless, it is not entirely clear how they work or why they can take weeks or months to produce a positive effect—the brain is a highly complex organ.

The most popular medications are called selective serotonin reuptake inhibitors (SSRIs). SSRIs include fluoxetine (Prozac), citalopram (Celexa), and sertraline (Zoloft), among others. Serotonin and norepinephrine reuptake inhibitors (SNRIs) are similar to SSRIs and include venlafaxine (Effexor) and duloxetine (Cymbalta). Now in use for decades, SSRIs and SNRIs coexist with older classes of antidepressants: tricyclics—named for their chemical structure—and monoamine oxidase inhibitors (MAOIs). The SSRIs and SNRIs tend to have fewer major side effects than the older drugs. However, medications affect everyone differently and there is no one-size-fits-all medication. Tricyclics and MAOIs remain important antidepressants. Finding a medication regimen that works for any particular patient may take trials of more than one antidepressant and more than one type of antidepressant.

Antidepressants typically take time to work. Patients must take regular doses for at least three to four weeks before they are likely to experience a full therapeutic effect and continue taking the medication to maintain improved mood and to prevent a relapse of the depression. Although antidepressants are not habit-forming or addictive, abruptly ending an antidepressant treatment can cause withdrawal symptoms or lead to a relapse. Some individuals, such as those with chronic or recurrent depression, may need to stay on the medication indefinitely.

Despite the relative safety and popularity of SSRIs and other antidepressants, some studies have suggested that they may have unintentional effects on some people, especially adolescents and young adults. The U.S. Food and Drug Administration requires a "black box" warning label on all antidepressant medications to alert the public about the potential increased risk of suicidal thinking or attempts in children, adolescents, and young adults taking antidepressants. 

Side effects can limit the usefulness of SSRIs, SNRIs, tricyclics, and MAO inhibitors. People taking MAOIs must adhere to significant food and medicinal restrictions—from wine and cheese to decongestants— to avoid potentially serious interactions. Patients taking an MAO inhibitor should receive a complete list of prohibited foods, medicines, and substances at the time of prescription. The most common side effects of tricyclic antidepressants include dry mouth, constipation, difficulty emptying the bladder, sexual problems, blurred vision, dizziness, and daytime drowsiness. The most common side effects associated with SSRIs and SNRIs include headache, nausea, nervousness and insomnia, agitation, ands decreased libido.

The newest medication in the antidepressant arsenal is ketamine, an agent long used safely as an anesthetic. In randomized, controlled trials, a molecular variant of ketamine, called esketamine, has recently been found safe and effective as a treatment for depression. Administered by nasal spray, it acts very rapidly to improve mood. Further, studies show that it also reduces suicidal thinking. It is not fully clear how esketamine produces its antidepressant effects, but the drug has a mechanism of action that is different from any other available antidepressant drug. It binds to NMDA receptors in the brain, blocking uptake of the excitatory neurotransmitter glutamate, which causes a rapid increase in glutamate levels. The glutamate burst ultimately strengthens neural circuits in areas of the brain involved in motivation, memory, and mood, known to be impaired in depression. The new drug, trade-named Spravuto, is intended for adults with treatment-resistant depression and, because of its potential for abuse, is administered in doctors' offices.

Herbal Therapy

Over the years, there has been considerable interest in the use of herbs for the treatment of both depression and anxiety. St. John's wort (Hypericum perforatum), often used in Europe, has aroused interest in the United States as well, as it has been used for centuries in many folk and herbal remedies. A number of modern studies have tested the effectiveness of St. John's wort for depression.

According to the National Center for Complementary and Integrative Health, "St. John’s wort isn’t consistently effective for depression. Do not use it to replace conventional care or to postpone seeing your health care provider." Further, "St. John’s wort limits the effectiveness of many prescription medicines. Combining St. John’s wort and certain antidepressants can lead to a potentially life-threatening increase in your body’s levels of serotonin, a chemical produced by nerve cells."

Neurostimulation Therapies

Electroconvulsive therapy (ECT) is useful, particularly for individuals whose depression is severe or life threatening, or for those who cannot take antidepressant medication. ECT often is effective in cases where antidepressant medications do not provide sufficient relief of symptoms. In recent years, ECT has been much improved. A muscle relaxant is given before treatment, which is done under brief anesthesia. Electrodes are placed at precise locations on the head to deliver electrical impulses. The stimulation causes a brief (about 30 seconds) seizure within the brain. The person receiving ECT does not consciously experience the electrical stimulus. For full therapeutic benefit, at least several sessions of ECT, typically given at the rate of three per week, are required.

Lifestyle Changes

Research shows that a number of factors in daily living have a positive effect on mood states. These include a nutrient-rich diet, physical activity, exposure to sunlight and outdoors, and social activity. Lifestyle changes that address these factors are increasingly considered a wise course in any treatment plan.

How to Help Yourself If You Are Depressed

Depressive disorders can make a person feel exhausted, worthless, helpless, and hopeless. Such negative thoughts and feelings make people feel like giving up. It is important to realize that such negative views are part of the disorder and typically do not reflect actual circumstances. Negative thinking fades as treatment begins to take effect. In the meantime:

  • Try to be with other people and to confide in someone; it is usually better than being alone and secretive.
  • Participate in activities that may make you feel better.
  • Even mild exercise, going to a movie or a ball game, or participating in religious, social, or other activities can help.
  • Expect your mood to improve gradually; it takes time.
  • Because depression distorts thinking, it is advisable to postpone important decisions until the depression lifts. Before deciding to make a significant transition—change jobs, get married or divorce—discuss it with others who know you well and have a more objective view of your situation.
  • Let family and friends help you.

How Family and Friends Can Help a Depressed Person

The most important thing anyone can do for a depressed person is to help him or her get an appropriate diagnosis and treatment. It may require making an appointment on their behalf and accompanying them to the doctor. Encourage a loved one to stay in treatment is helpful.

Emotional support is also invaluable. This involves understanding, patience, affection, and encouragement. Engage the depressed person in conversation and listen carefully. Do not disparage feelings expressed, but point out realities and offer hope. Do not ignore remarks about suicide. Report them to the depressed person's therapist. Invite the depressed person for walks, outings, to the movies, and other activities. Keep trying. Although diversions and company are needed, too many demands may increase feelings of failure. Remind your friend or relative that with time and treatment, the depression will lift.

References

  • American Psychiatric Association, Diagnostic and Statistical Manual, Fifth Edition  
  • National Institutes of Health
  • National Health and Nutrition Examination Survey
  • Archives of Internal Medicine
  • Psychopharmacology Bulletin
  • Journal of the American Medical Association
  • National Institute of Mental Health
  • U.S. Department of Health and Human Services
  • Biological Psychiatry
  • Altshuler LL, Hendrich V, Cohen LS. Course of mood and anxiety disorders during pregnancy and the postpartum period. Journal of Clinical Psychiatry, 1998; 59: 29.
  • Rohan KJ, Lindsey KT, Roecklein KA, Lacy TJ. Cognitive-behavioral therapy, light therapy and their combination in treating seasonal affective disorder. Journal of Affective Disorders, 2004; 80: 273-283.
  • Tsuang MT, Faraone SV. The genetics of mood disorders. Baltimore, MD: Johns Hopkins University Press, 1990.
  • Tsuang MT, Bar JL, Stone WS, Faraone SV. Gene-environment interactions in mental disorders. World Psychiatry, 2004 June; 3(2): 73-83.
  • Schmidt PJ, Nieman LK, Danaceau MA, Adams LF, Rubinow DR. Differential behavioral effects of gonadal steroids in women with and in those without premenstrual syndrome. New England Journal of Medicine. 1998 Jan 22; 338(4): 209-216
  • Dreher JC, Schmidt PJ, Kohn P, Furman D, Rubinow D, Berman KF. Menstrual cycle phase modulates reward-related neural function in women. Proceedings of the National Academy of Sciences. 2007 Feb 13; 104(7): 2465-2470.
  • Pollack W. Mourning, melancholia, and masculinity: recognizing and treating depression in men. In: Pollack W, Levant R, eds. New Psychotherapy for Men. New York: Wiley, 1998; 147 66.
  • Cochran SV, Rabinowitz FE. Men and depression: clinical and empirical perspectives. San Diego: Academic Press, 2000.
  • Gallo JJ, Rabins PV. Depression without sadness: alternative presentations of depression in late life. American Family Physician, 1999; 60(3): 820-826.
  • Reynolds CF III, Dew MA, Pollock BG, Mulsant BH, Frank E, Miller MD, Houck PR, Mazumdar S, Butters MA, Stack JA, Schlernitzauer MA, Whyte EM, Gildengers A, Karp J, Lenze E, Szanto K, Bensasi S, Kupfer DJ. Maintenance treatment of major depression in old age. New England Journal of Medicine, 2006 Mar 16; 354(11): 1130-1138.
  • Rush JA, Trivedi MH, Wisniewski SR, Stewart JW, Nierenberg AA, Thase ME, Ritz L, Biggs MM, Warden D, Luther JF, Shores-Wilson K, Niederehe G, Fava M. Bupropion-SR, Sertraline, or Venlafaxine-XR after failure of SSRIs for depression. New England Journal of Medicine, 2006 Mar 23; 354(12): 1231-1242.
  • Trivedi MH, Fava M, Wisniewski SR, Thase ME, Quitkin F, Warden D, Ritz L, Nierenberg AA, Lebowitz BD, Biggs MM, Luther JF, Shores-Wilson K, Rush JA. Medication augmentation after the failure of SSRIs for depression. New England Journal of Medicine, 2006 Mar 23; 354(12): 1243-1252.

Last reviewed 02/26/2019