Mood Disorders

Dr. C. George Boeree

[Note:  The quotations below are from Mental Health:  A Report of the Surgeon General, U.S. Public Health Services (1999), available at http://www.surgeongeneral.gov/library/mentalhealth/home.html]

The cardinal symptoms of major depressive disorder are depressed mood and loss of interest or pleasure. Other symptoms vary enormously. For example, insomnia and weight loss are considered to be classic signs, even though many depressed patients gain weight and sleep excessively.

It is twice more common in women than in men.

What is now called major depressive disorder, however, differs both quantitatively and qualitatively from normal sadness or grief. Normal states of dysphoria (a negative or aversive mood state) are typically less pervasive and generally run a more time-limited course. Moreover, some of the symptoms of severe depression, such as anhedonia (the inability to experience pleasure), hopelessness, and loss of mood reactivity (the ability to feel a mood uplift in response to something positive) only rarely accompany “normal” sadness. Suicidal thoughts and psychotic symptoms such as delusions or hallucinations virtually always signify a pathological state.

When untreated, a major depressive episode may last, on average, about 9 months. Eighty to 90 percent of individuals will remit within 2 years of the first episode (Kapur & Mann, 1992). Thereafter, at least 50 percent of depressions will recur, and after three or more episodes the odds of recurrence within 3 years increases to 70 to 80 percent if the patient has not had preventive treatment (Thase & Sullivan, 1995).

Anxiety is commonly comorbid with [occuring at the same time as] major depression. About one-half of those with a primary diagnosis of major depression also have an anxiety disorder (Barbee, 1998; Regier et al., 1998). The comorbidity of anxiety and depression is so pronounced that it has led to theories of similar etiologies [causes], which are discussed below. Substance use disorders are found in 24 to 40 percent of individuals with mood disorders in the United States (Merikangas et al., 1998). Without treatment, substance abuse worsens the course of mood disorders. Other common comorbidities include personality disorders (DSM-IV) and medical illness, especially chronic conditions such as hypertension [high blood pressure] and arthritis.

Suicide is the most dreaded complication of major depressive disorders. About 10 to 15 percent of patients formerly hospitalized with depression commit suicide (Angst et al., 1999). Major depressive disorders account for about 20 to 35 percent of all deaths by suicide (Angst et al., 1999). Completed suicide is more common among those with more severe and/or psychotic symptoms, with late onset, with co-existing mental and addictive disorders (Angst et al., 1999), as well as among those who have experienced stressful life events, who have medical illnesses, and who have a family history of suicidal behavior (Blumenthal, 1988). In the United States, men complete suicide four times as often as women; women attempt suicide four times as frequently as do men (Blumenthal, 1988).

Dysthymia is a chronic [recurring, usually less severe] form of depression.

Depression is related, of course, to sadness.  Sadness is a natural response to difficult circumstances that cannot be resolved by running away (that would be fear) or attacking the problem (that would be anger).  Instead, there is the sense that one must wait for the problem to resolve by itself.  In grief, for example, we ultimately realize that only time will lessen the pain.

We consider sadness to have passed over into pathology when we lose the sense that the pain will lessen.  We continue to suffer, we have guilt feelings, we obsessly dwell on the problem, we even try to shut down our feelings altogether.  Traumatic events such as the sickness or death of a loved one are common causes of depression.

But continual stress is also a common cause of depression.  Living with stress causes the depletion of the body's resources, including changes in the availability of the neurotransmitters associated with energy, happiness, and calm.  With repeated stress, the nervous system becomes increasingly sensitive to additional stress, until it no longer seems to be able to cope.  A simple way to say this is that you become emotionally exhausted from life's difficulties.

We find depression more commonly in people who live in the face of poverty, discrimination, and exploitation.  It is not a complete surprise that 70% of depressed people are women, as living in a male-dominated society adds to the stresses women must deal with.  It is also more common among people in stigmatized populations.  Cultural psychologist Richard Castillo even suggests that treating depression as a "brain disease" is a way society avoids facing the significant social problems that lead to depression, in the same way that focussing on "cracking down" on drug addicts or petty criminals allows us to ignore the social situations that lead people to engage in those behaviors.

One well-known explanation of depression considers it a matter of learned helplessness.  If we see ourselves as helpless in the face of stress and trauma, if we see our suffering as hopeless, we develop depression.  This leaves a dilemma for psychologists:  It often helps people to see depression as a "brain disease" involving low seratonin levels, since they can stop seeing themselves as somehow responsible for their condition.  But that also means they now see depression as something that can only be helped by external medical intervention.

Depression is not as common in many nonwestern and premodern cultures.  In those cultures, it is more likely that emotional exhaustion is expressed via somatization, i.e. in the form of physical complaints.  Castillo suggests that the prevalence of depression in modern western societies such as the U.S. is due to our emphasis on financial success, material values, and the idea that we each have individual responsibility for our own happiness.  In other societies, people rely more on defined status, tradition, and the social support of extended family.  Also in other societies, people don't see happiness as a right.  In the U.S., if you are not happy, we assume that there is something terribly wrong!

 Bipolar Disorder

Bipolar disorder is a recurrent mood disorder featuring one or more episodes of mania or mixed episodes of mania and depression (DSM-IV; Goodwin & Jamison,1990). Bipolar disorder is distinct from major depressive disorder by virtue of a history of manic or hypomanic (milder and not psychotic) episodes.

Mania is derived from a French word that literally means crazed or frenzied. The mood disturbance can range from pure euphoria [strong happiness] or elation to irritability to a labile [changeable] admixture that also includes dysphoria [unhappiness] (Table 4-4). Thought content is usually grandiose but also can be paranoid. Grandiosity usually takes the form both of overvalued ideas (e.g., “My book is the best one ever written”) and of frank delusions (e.g., “I have radio transmitters implanted in my head and the Martians are monitoring my thoughts.”) Auditory and visual hallucinations complicate more severe episodes. Speed of thought increases, and ideas typically race through the manic person’s consciousness. Nevertheless, distractibility and poor concentration commonly impair implementation. Judgment also can be severely compromised; spending sprees, offensive or disinhibited behavior, and promiscuity or other objectively reckless behaviors are commonplace. Subjective energy, libido [sexual desire], and activity typically increase but a perceived reduced need for sleep can sap physical reserves. Sleep deprivation also can exacerbate [make worse] cognitive difficulties and contribute to development of catatonia [staying in one position for long periods of time] or a florid [fully developed], confusional state known as delirious mania.

Cyclothymia is marked by manic and depressive states, yet neither are of sufficient intensity nor duration to merit a diagnosis of bipolar disorder or major depressive disorder.

It is likely that mania involves a certain amount of dissociation - that is, a refocussing of attention away from painful situations (especially social ones) and onto a powerful, grandiose fantasy.  So bipolar disorder may be a matter of an energetic fantasy phase followed by emotional exhaustion followed by another energetic fantasy phase, and so on.

Mania is sometimes associated with creativity, and a number of famous writers, artists, musicians, and others are believed to have been bipolar.  They would be depressed for months, and then have bursts of energetic creative activity, only to fall back into depression.  People believed to have been bipolar include Ludwig von Beethoven, Abraham Lincoln, Winston Churchill, Isaac Newton, Charles Dickens, Edgar Allen Poe, Mark Twain, Virginia Woolf, Kurt Vonnegut Jr., Edvard Munch, Vincent van Gogh, Marilyn Monroe, Jimmy Hendrix, Sting, Ozzie Osbourne, Adam Ant, and Kurt Cobain.