Major Depressive Disorder, Unipolar Depression, Psychotic Depression, Depressive Psychosis

What is depression?

Depressive illness is a sustained period of intense sadness or extreme apathy accompanied by a variety of symptoms that cause considerable distress and/or a decline in general level of functioning. The most common symptoms are irritability, poor concentration, social withdrawal, somatic complaints, disturbances in sleep, decreased appetite, and a loss of capacity to experience pleasure (anhedonia).

Previously, psychiatrists divided episodes of depression into two types: those with an obvious cause (so-called situational or reactive depressions) and those where no apparent cause was present (endogenous depressions).

With the exception of bereavement, current diagnostic and treatment guidelines make no reference to the presence or absence of a cause unless the depressive symptoms can be attributed to the direct physiological effects of a medical condition, to medications, or to substance abuse.

Depression is one of the more common psychiatric illnesses and, unless actively treated, may result in suicide. In individuals with more than one episode of major depression, as many as fifteen percent will commit suicide. Estimates vary widely, but lifetime prevalence is in the neighborhood of fifteen to twenty percent for women and perhaps one-half that for men.

The course of the illness is variable. Some individuals may have several bouts of unexplained depression throughout their lives and many have close relatives with similar problems, while others may have a single episode attributable to a period of prolonged or extreme stress. Still others may have a seasonal component and respond to therapy with bright lights.

There is also a high incidence of depression associated with physical illness such as stroke, cancer, and myocardial infarction. The post-partum period is also associated with a greatly elevated risk of depression, which suggests hormonal factors may be important.

Social cultures appear to influence how members experience depression. Symptoms may be primarily of a physical nature (usually multiple vague complaints for which no cause can be found) or even of a "spiritual" nature in which the individual may describe being bewitched or possessed.

How is it diagnosed?

The history is of greatest importance in establishing the diagnosis, but a physical exam and laboratory tests should be done in every new case of suspected depression.

History: A thorough history is vital in making the diagnosis of depression. Whenever possible, corroborative history from friends, family members, or employers should be sought. Besides addressing the above criteria, it is important to question whether there is a family history of depression or of suicides, and a careful, non-judgmental inventory of substance abuse should be made in every case as this requires specific treatment measures of its own. Further, a general history of psychological problems might predispose one to depression and should always be explored.

One of the difficulties in accurately diagnosing depression is distinguishing the normal sadness following a major disappointment or loss from clinical depression. All humans experience sadness periodically and, following episodes of loss or extreme stress, individuals may develop some symptoms of depression, yet still not be considered as suffering from a clinical depression.

The fourth edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) is explicit. According to the DSM-IV, one of the major criteria is that the "symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning." And, at least five of the symptoms present must include the following:

  • depressed mood most of the day and nearly every day,
  • a marked reduction in interest or pleasure in almost all activities,
  • a major weight change (unless dieting) or change in appetite,
  • a significant change in sleep patterns (either too little or too much),
  • a noticeably different level of general physical activity (to others),
  • profound fatigue or energy loss,
  • feelings of worthlessness or excessive guilt,
  • decreased ability to think or concentrate (normal indecisiveness also counts),
  • or recurrent thoughts of death or suicide, or an actual recent attempt.

DSM-IV further specifies that these five or more symptoms must be present most of the day, nearly every day, for at least two weeks.

In other words, feeling tired only on awakening might indicate a significant change in sleep patterns, but should not be taken by itself to mean that fatigue or a different level of physical activity is present. Also, if the symptom is due to a general medical condition or medication the individual is taking, it should not be counted.

Examples here might include hyperactivity from a thyroid condition or poor appetite from cancer chemotherapy. There are two other situations in which depression may not be diagnosed. Bereavement is considered an appropriate reaction to the death of a loved one and is expected to cause many of the above symptoms. Treatment is seldom necessary, but if the symptoms are severe or persist for more than two months, it is then considered a major depressive episode and should be treated accordingly.

The other situation is substance abuse. Virtually all substances of abuse, including alcohol, are capable of causing a depression. While it may be that the individual is seeking to self-medicate a concurrent depression, until the symptoms are observed to persist after a period of abstinence of between one and six months depending on the substance(s) being used, the diagnosis of a substance induced mood disorder is used instead of depression. It should be remembered, though, that from the standpoint of disability, both bereavement and a substance induced depression may be occupationally debilitating.

Physical exam: Hyperthyroidism and other glandular disturbances, cancer, stroke, and heart attack are a few of the illnesses that frequently cause depression. By virtue of their dramatic nature, victims of many of these illnesses are likely to have sought medical attention for reasons other than depression; but, in other cases where the disease process is less acute and without many outward signs, depression may be the only complaint. In every case of newly suspected depression, therefore, a thorough physical and laboratory exam should be performed.

Tests: Routine laboratory testing is recommended. Additionally, there are some more specialized endocrine tests that may be helpful in establishing the diagnosis. CT scan may also be requested, although brain tumor or a clinically silent stroke are relatively rare causes. Psychological testing may also be used, especially as a means of assessing severity and response to treatment.

How is depression treated?

Treatment consists of psychotherapy, medications, or both. Today, there are any number of effective antidepressant medications that differ primarily in cost and side-effect profile. About two-thirds of those treated will respond to one or more medications. Generally, these medications will take at least seven to ten days to start to work and may take much longer than that to achieve their full effect.

A risk then is of abandoning treatment too soon when improvement is not immediate; because the newer medications are much safer, physicians can prescribe effective doses early on with a lesser risk or patient non-compliance.

Unless the depression is mild, psychotherapy alone is generally not recommended. There are any number of different types of psychotherapy that have been used successfully. A common and effective approach is to use a combination of medications and psychotherapy. This helps to ensure that the individual remains safe until improvement occurs. In some instances, the risk of self-harm is so high or personal neglect so great as to warrant psychiatric hospitalization.

Finally, it should be mentioned that some cases of depression are treatment resistant; that is no combination of medications or psychotherapy seems to provide adequate relief. In this circumstance, electroconvulsive therapy (ECT) is the treatment of choice. Despite popular misconception, electroconvulsive therapy is safe and extremely effective.


  • Antidepressant drugs for some persons with prolonged or moderately severe depression.
  • Lithium for alternating mania and depression.
Information Brand Generic Label Rating
Sertraline Zoloft Sertraline On-Label
Elavil without prescription Elavil Amitriptyline On-Label
Generic Paroxetine Paxil Paroxetine On-Label
Zyban antidepressant Zyban Bupropion On-Label
Lexapro online Lexapro Escitalopram On-Label
Effexor Effexor Venlafaxine On-Label

Prozac (Fluoxetine), Klonopin (Clonazepam), Xanax (Alprazolam), Luvox (Fluvoxamine), Celexa (Citalopram), Zyprexa (Olanzapine), Desyrel (Trazodone), Remeron (Mirtazapine), Seroquel (Quetiapine)

What might complicate it?

Substance abuse, especially alcohol, is prevalent in this population, though in this case, it is often difficult to determine which problem is primary. Insomnia is an extremely common complaint.

Anxiety also often accompanies depression and may require treatment of its own; fortunately, anxiety disorders will frequently respond to the same antidepressant medications as the depression, reinforcing the view of some that the two share common brain chemistry imbalances.

Approximately one in ten with a major depressive episode will subsequently be diagnosed as having bipolar mood disorder, a chronic condition that may only partly respond to treatment.

In some cases, an episode of mania (see bipolar mood disorder) may emerge as a result of antidepressant medication use. In extremely severe cases, psychotic symptoms may be present. These may be in the form of auditory hallucinations (hearing voices) or delusions (false beliefs).

Suicide attempts are alarmingly common and may occur as the individual begins to respond to therapy. This contradiction is explained when one considers the extreme apathy sometimes seen in severe depression; the individual literally does not have the motivation or energy to commit suicide. Some major risk factors include a history of previous attempts, substance abuse, major medical illness, male gender, and the presence of psychotic symptoms.

Predicted outcome

Most individuals with a major depressive episode will get better. For the recovery to be spontaneous, it may take months and places the individual at such high risk of complications it is unthinkable not to intervene. The number of medications available continues to grow and most individuals will respond to these and/or psychotherapy.

With time, recovery is usually complete, though risk of relapse increases with each episode. More than half of all individuals with one episode of major depression will have another, while those individuals with a history of three previous episodes have a 90% likelihood of having a fourth. This has a significant impact on treatment. For example, it is now recommended that individuals with a history of multiple depressive episodes receive medication for the rest of their lives.


Bipolar mood disorder often consists at least partly of recurrent episodes of mild to severe depression. Often, the initial mood swings that characterize this condition are one or more episodes of depression. Only later does a manic episode reveal the correct diagnosis.

It should also be emphasized that depressive illness is part of a spectrum that ranges from so-called dysthymia to major depressive disorder. Dysthymia will share in common some of the features of depression but will not satisfy all of the criteria, the most important is that it does not represent a marked departure from the individual's normal mood and the adverse impact on social and occupational functioning seen in major depression is not present.

An adjustment disorder with depressed mood may come close to meeting criteria for major depression. Posttraumatic stress disorder may lead to a major depression and other anxiety disorders may share common elements as well.

Schizophrenia and other forms of psychosis may have as a major symptom a marked deficit in outward emotion and purposeful activity. This may be virtually impossible to distinguish from a psychotic depression at the time of presentation, especially in a younger individual with no psychiatric history. The same holds true for schizoaffective disorder, which represents a combination of simultaneous psychosis and mood change.

Finally, recall that the diagnostic criteria for depression insist that substance abuse, depression, and bereavement be ruled-out as the primary cause.

Appropriate specialists

Psychiatrist, psychologists, and other mental health professionals.

Last updated 21 December 2015


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