Depression is a mood disorder in which a person loses interest or pleasure in life. Leading symptoms of depression include feeling hopeless, worthless, and a loss of energy.
Clinically speaking, depression may be diagnosed as one of several different types of depressive disorders: major depressive disorder, dysthymia, disruptive mood dysregulation disorder, premenstrual dysphoric disorder, substance/medication-induced depressive disorder, depression caused by another medical condition, or unspecified depressive disorder.
Major depressive disorder (clinical depression) is diagnosed when a person experiences a depressed mood or a loss of interest or pleasure with feelings of sadness, emptiness or hopelessness on most days during at least a two-week period. Children or adolescents may demonstrate irritability. In addition, a diagnosis for major depressive disorder requires at least four of the following symptoms to be experienced on most days:
Dysthymia, also known as persistent depressive disorder, is less severe than major depressive disorder. It is characterized by a depressed mood for most of the day, on more days than not, for at least two years. In addition, dysthymia is diagnosed when a person experiences two or more of the following symptoms:
Disruptive mood dysregulation disorder is characterized by severe recurrent temper outbursts expressed verbally and/or behaviorally. A person with this disorder will show physical aggression toward people or property that is grossly out of proportion in intensity or duration to the situation or provocation. The temper outbursts occur, on average, three or more times per week and are inconsistent with the individual’s developmental level. Moreover, the individual’s mood between temper outbursts is persistently irritable or angry most of the day, nearly every day.
A diagnosis for this condition may occur when:
A diagnosis for disruptive mood dysregulation disorder cannot coexist with a diagnosis of oppositional defiant disorder, intermittent explosive disorder, or bipolar disorder. However, it can coexist with major depressive disorder, attention deficit hyperactivity disorder (ADHD), conduct disorder, and substance abuse disorders.
Premenstrual dysphoric disorder is a condition similar to Premenstrual Syndrome (PMS), but it is more serious. This type of depression is diagnosed when at least five symptoms are experienced in the final week before the onset of a woman’s menstrual period. The symptoms improve within a few days after a woman’s period begins and become minimal or absent in the week after her period ends. Among the symptoms listed below, at least one symptom must be present from symptoms 1-4, and at least one from symptoms 5-11:
Substance/medication-induced depressive disorder occurs when a person experiences a depressed mood, or greatly diminished interest or pleasure in activities, during or after substance intoxication or withdrawal, or after taking a medication. Substances that can cause depression include alcohol, cocaine, opioids, sedatives, amphetamines, inhalants, phencyclidine, or other substances.
A person can be diagnosed with depressive disorder due to another medical condition when there is evidence from the history, physical examination, or laboratory findings that the depression is the direct consequence of another medical condition. Requirements for this diagnosis also include:
A diagnosis of “unspecified depressive disorder” is used when symptoms of depression cause significant distress or impairment in social, occupational, or other important areas of functioning but do not meet the full criteria for any of the depressive disorder diagnoses. This diagnosis may be used with any of the following groups of symptoms:
Thyroid dysfunction can be a direct cause of depression.
Depression may be associated with the development of heart disease, stroke, diabetes, hypertension, hyperlipidemia, obesity, and autoimmune diseases such as multiple sclerosis or lupus. It also causes poor outcomes from these conditions.
Depression may increase the likelihood of smoking, drug or alcohol use, lack of physical activity, and lack of social contact with others.
Yes, women are two times more likely to experience depression than men, despite the country or culture that they live in. Reasons for this difference are thought to involve hormonal differences, the effects of childbirth, different psychosocial stressors for women and for men, and, for some women, behavioral models of learned helplessness.
No, there is no association with an increase in depression and a person’s age.The average age of onset for major depressive disorder is about 40 years, with 50 percent of all patients experiencing a major depressive disorder between the ages of 20 and 50. Recent data suggests that major depressive disorder may also be increasing among people younger than 20 years of age. This may be related to an increased use of alcohol and drugs in this age group.
Major depressive disorder occurs most often in individuals who have divorced or separated, or those without close interpersonal relationships.
Yes, approximately 5-10 percent of people evaluated for depression have previously undetected thyroid dysfunction. Thyroid dysfunction is reflected by an elevated basal thyroid-stimulating hormone (TSH) level found in laboratory tests. Such abnormalities are often associated with elevated anti-thyroid antibody levels. Unless corrected with hormone replacement therapy, this problem can compromise a person’s response to antidepressant medication treatment.
In addition, approximately 20-30 percent of depressed patients show a blunted TSH response, indicating an increased risk for relapsing into depression despite preventative antidepressant therapy. This problem is more difficult to treat.
Yes, clinically depressed individuals often have shortened cycles of deep sleep and are more easily awakened. Some younger depressed patients may have the opposite experience and sleep longer than normal. Patients with an abnormal sleep profile have found to be less responsive to psychotherapy and may benefit more from antidepressant medication.
Yes, depressive disorders are associated with several elements of immune dysfunction. This includes lower levels of lymphocytes, which are types of white blood cells responsible for the body’s ability to fight off infections. That’s why it’s so important to take care of one’s mental health, as well as one’s physical health.
Yes, people who excessively use drugs to alter their mental state (such as alcohol, narcotics, or cocaine) are more likely to experience depression.
Yes, individuals who experience social anxiety disorder and/or panic attacks have an increased risk of depression.
Yes, women are two times more likely than men to experience depression overall. In addition, there are other different risk factors between men and women when it comes to depression. Men with substance abuse problems more frequently experience depression than women who abuse drugs. Meanwhile, women with anxiety or eating disorders more frequently become clinically depressed than men with these same issues.
Depression, in most cases, is caused by a combination of multiple factors. These factors can include genetic susceptibility, live events, environmental stress, and psychodynamic considerations.
Biological Factors
Genetic Factors
Studies indicate that if one parent has a mood disorder, such as major depressive disorder, their child will have a 10 to 25 percent risk for a mood disorder. If both parents are affected, the risk for their child approximately doubles. In addition, the more members of a family that are affected by a mood disorder the greater the risk is to a child.
Studies of twins provide evidence that genes account for 50 to 70 percent of genetic mood disorders. Environmental or other factors are thought to account for the remainder. Studies showthat the rate of mood disorders shared by twins is higher among identical twins (70 to 90 percent) than among fraternal twins (16 to 35 percent).
Psychosocial Factors
Cognitive Theory
Cognitive theory asserts that depression can develop in individuals with cognitive distortions (inaccurate thoughts), such as negative perceptions towards themselves, the world, and their future (Aaron Beck). Depressed patients may have cognitive distortions, drawing a specific conclusion without sufficient evidence. They may also focus on a single detail while ignoring other, more important aspects of an experience. Likewise, they may form conclusions based on limited experience, or they may overvalue or undervalue the significance of a particular event.
Learned Helplessness
The learned helplessness theory connects depression to the experience of uncontrollable events. Adverse external events cause a loss of self-esteem, leading to depression. Behaviorists who subscribe to this theory believe that improving one’s depression in such a case depends on the patient learning a sense of control and mastery of one’s environment.
Treatment for depression can involve several strategies. Most studies indicate that a combination of psychotherapy and antidepressant medication is the most effective treatment for major depressive disorder. Either medication or psychotherapy alone is effective in treating patients with mild depression.
There are several groups of antidepressants that are used to treat depression:
Cognitive Behavioral Therapy (CBT) – Short Term Therapy
The goal of cognitive behavioral therapy is to change patterns of thinking or behaviors associated with people’s difficulties, resulting in improving the way they feel. CBT works by changing people’s attitudes, behaviors, and how they deal with emotional problems by focusing on their thoughts, images, beliefs and attitudes. Most studies have found that cognitive behavioral therapy is as effective as medication in treating major depressive disorder.
Interpersonal Therapy – Short Term Therapy
Interpersonal therapy, developed by Gerald Klerman, focuses on one or two of a patient’s current interpersonal problems. During the course of treatment, therapy may address a patient’s defense mechanisms, internal conflicts, lack of assertiveness, limited social skills, or distorted thinking.
Supportive Psychotherapy -- Short to Long Term Therapy
This is a type of psychotherapy that integrates various components of psychodynamic, CBT and interpersonal psychotherapy. It helps to improve symptoms and to maintain, restore, or improve self-esteem, ego functions, and adaptive skills.
Psychodynamic Psychotherapy -- Short to Long Term
The goal of this psychotherapy is to study the psychological forces that underlie human behavior, feelings, and emotions and how they might relate to early experiences. Psychodynamic psychotherapy works to uncover repressed childhood experiences that are thought to explain an individual’s current difficulties.
Psychoanalytic Psychotherapy – Long Term Therapy
The goal of psychoanalytic psychotherapy is to effect a change in an individual’s personality or character, such as improving interpersonal trust, capacity for intimacy, coping mechanisms, the capacity to grieve, and the ability to experience a wide range of emotions. Treatment may continue for several years.
Family Therapy– Short Term Therapy
Family therapy is not generally viewed as primary therapy for the treatment of the major depressive disorder. However, family therapy will be considered if the depression jeopardizes the functioning of a patient’s marriage or family, or if the depression is promoted or maintained by the family situation.
A certain number of patients may have treatment-resistant depression, meaning they do not get better with medication and therapy. For these patients, treatments including transcranial magnetic stimulation (TMS) or electroconvulsive therapy (ECT) can help.