Fleeting moments of feeling sad and blue or depressed are part of the human condition. These mood changes are normal and tell you that something is not quite right in your life and usually pass. Clinical depression is different. It is persistent, impairing and includes a range of symptoms. There are different types of depression. Usually your therapist will make an effort to determine the type you have.
Major Depressive Disorder
Major depressive disorder, which is the most common of the depressions, includes a sad or dysphoric mood and loss of interest or pleasure in all or almost all usual activities or pastimes. This mood state persists for several weeks and is associated with other symptoms which occur nearly every day including a disturbance in your appetite (loss or increase in appetite), changes in weight, sleep disturbance (trouble falling asleep, waking up in the middle of the night and not being able to go back to sleep, waking up early in the morning and feeling dreadful), and a loss of interest and pleasure in things you used to enjoy: food, sex, work, your family and friends. Symptoms of agitation or feeling sluggish, a decrease in energy, feeling worthless or guilty, having trouble concentrating or thinking, thoughts of death, feeling life is not worth living, suicide attempts or even suicide are other features of depression.
You do not need to have all of the symptoms to have a clinical depression. However, if you have at least five symptoms and they persist for several weeks, resulting in impaired ability to take care of yourself or your family, or impaired ability to go to work and carry out your daily life, then you probably have major depressive disorder.
Subtypes of Major Depressive Disorder
It has been known for a long time that there are different forms of major depressive disorder usually defined by a particular group of symptoms. Many types have been suggested. However, research studies show that the type with the most important treatment implications is delusional depression.
Delusional depression, also called psychotic depression, includes the usual symptoms of depression as well as distortions of thinking which are consistent with depressive themes such as guilt, self-blame, feeling of personal inadequacy or deserved punishment. A person with delusional depression may feel that the depression was brought on because they are bad or because they deserve to be depressed. Delusional depression is quite infrequent. When it does occur, it requires medication and usually cannot be treated by psychotherapy or IPT alone.
Many persons have mild depression, e.g. sleep problems or loss of interest, which do not meet the criteria for major depressive disorder. These states are referred to by different names: minor depression; depression not otherwise specified; mixed anxiety/depression; or adjustment disorder with depressed mood. People with these mild symptoms either do not go for treatment or are only seen by their family doctor, a primary care practice or a health maintenance organization (HMO). These symptoms should not be ignored if they persist since they are 3 impairing and can interfere with your enjoyment of life and productivity. Moreover, persons with minor depressive symptoms are at increased risk for developing major depressive disorder in the near future.
IPT (Interpersonal Psycho-Therapy) has been adapted for persons with mild depressive symptoms. In one study, two groups of mildly depressed people were examined. In die first group, patients received IPT modification administered by nurses while the other group of patients received no treatment. The group involved in the IPT treatment showed a reduction in their symptoms. Another study is underway in a primary care setting.
The main feature of dysthymia is a chronic disturbance of mood, i.e., feeling sad or blue, loss of interest in almost all usual activities (similar to depression), but not of sufficient severity to meet criteria for major depressive disorder. These symptoms are mild, low-grade and are constant. They must persist for at least two years to be considered dysthymia but they can last for decades. IPT has been adapted to these symptoms and is being tested in patients with dysthymia.
Bipolar disorder includes the presence of manic states in addition to depression. Mania is a predominant mood which is either elevated (feeling high), expansive or irritable. It is accompanied by excess activity, racing thoughts, feeling powerful, overly high self-esteem, a decreased need for sleep, being easily distracted, and involvement in activities that have a high potential for painful consequences, such as excessive spending or sexual activities.
IPT has been adapted and is being tested for patients who have bipolar disorder and are receiving maintenance medication. Most patients with bipolar disorder require medication.
(extracted from) Mastering Depresion Through Interpersonal Psychotherapy, A Patient Workbook. By Myrna M. Weissman, Oxford University Press, 1995