| Cognitive behavioral models and depression: | One approach (Lewinsohn) suggests that depression may be due to inadequate or insufficient positive reinforcement either because the environment lacks such positive reinforcement or individual is not able to take advantage of reinforcement. Seligman suggested a theory of "learned helplessness." This theory suggests that depression may stem from cases in which an individual has lost (real or imagined) control over negative personal events in life. Aaron Beck
proposed depression develops when the individual cognitively misinterprets life events; furthermore, this approach has led to cognitive behavioral therapy. |
| Cognitive behavioral models of depression and cognitive triad of depression: | The "cognitive triad of depression" represents a conceptual core for the cognitive-behavioral model of depression. Three elements the described the core: negative self view ("things are bad because I am bad"); negative interpretation of experiences ("everything has always been bad"); negative view of the future ("everything always the bad"). This theory suggests that depressed individuals interpret the world through depressive frame of reference which distorts experienced towards a more negative interpretation. |
| Cognitive distortions described in the cognitive-behavioral model of depression: | Usual cognitive distortions involve arbitrary inference (the individual believes a negative event was caused by him or herself),
selective abstraction (the individual emphasizes the negative aspect in an otherwise positive set of information); and inexact labeling (in which an individual first describes an event with a distorted label and then reacts to the label rather than to the underlying event). |
| Principal feature of the major depressive episode: | Depressed mood or loss of interest or pleasure describe the principal feature. This presentation should predominate for at least two weeks and be of sufficient intensity to cause noteworthy distress or impairment in individual's social, occupational, or related areas of life activity. During this two-week. The patient must also present with at least four additional symptoms besides depressed mood or loss of interest or pleasure (anhedonia). |
| Most characteristic symptom in depression: |
Depressed mood (over 90% of patients). |
| Other than depressed mood, additional signs and symptoms of depression: | Anhedonia, as described earlier, change in appetite (about 70% of patients exhibited reduced appetite and weight loss), altered sleep patterns (about 80% of depressed patients present with sleep disturbance, with insomnia being the most common; alteration in body activity (about 50% of depressed patients show a reduction in their normal level of activity); reduction in energy level (nearly all depressed individuals feel significant reduction in energy (anergia), significant fatigue, as well as reduced efficiency; feelings of worthlessness along with inappropriate feelings of guilt (depression may result in a notable decrease in self-esteem); indecisiveness along with reduced concentration (about 50% of depressed individuals exhibit or feel a "slowing of thought")
This manifestation may result in difficulty in making decisions with a severe form, "pseudodementia", especially among older individuals, present with memory deficits sufficient be mistaken for early indications of dementia; suicidal ideation (some depressed individuals may experience recurrent thoughts of death-ranging from occasional feelings that others would be better off if they were no longer alive to the actual planning and implementation of suicide. |
| Melancholic subtype of depression: | Major depressive disorder with melancholic features is a diagnosis made when the individual expresses loss of pleasure in most activities or lack of reactivity to typically pleasurable experiences along with at least three of the following: a quality of depressed mood that is different from that likely experienced following,, for example, the loss of a loved one; depression tending to be usually worse in the morning; early-morning awakening, described as being at least two hours prior to the usual time; notable psychomotor retardation or agitation; marked anorexia or weight loss; Inappropriate or excessive guilt. |
| Atypical depression: | In this type of depression symptoms present that are typically opposite to those seen in melancholia. based on DSM-IV criteria, major depression with atypical features include mood reactivity in which the mood improves in response to the positive event along with at least two of the following: notable weight gain or improved appetite; hypersomnia; "leaden paralysis" (heavy, leaden feeling in arms or legs); long-term pattern of sensitivity to real or just perceived interpersonal rejection (not limited to episodes of mood disturbance). |
| Seasonal affective disorder: | Depressive episodes may be experienced by some individuals at particular times during the year. Episodes of seasonal affective disorder (SAD)
often begin in fall or winter and diminish in spring. Sometimes they may be present in summer. SAD
often responds to light therapy as well as to SSRIs. Seasonal pattern is required and is established
if the following behaviors are noted: regular time relationship between the onset of major depressive episodes in bipolar I or bipolar II disorder or major depressive order that is recurrent and correlated with a particular time of the year and full remissions or a transition from depression to mania or hypomania at a particular time of the year. |
| Psychological testing: | Psychological testing has not been found helpful in the development of a diagnosis of major depressive disorder. |
| Course of depressive illness: | Major depressive disorder may be preceded by dysthymic disorder (10%
in community samples at higher in clinical samples, up to 25%). Major depressive disorder may start at any age although the average age of onset is from the mid-teens to the late 20s. Symptoms often develop over a timeframe of days to weeks and preexisting conditions such as general anxiety, panic disorder, and/or phobias may be present. About half of patients presenting with major depressive disorder will have more than a singular episode. A second episode fulfills criteria for recurrent depression. |
| Course of recurrent depression: | Variable-some individuals experience a few isolated occurrences that are separated by long (years) stable intervals. Other individuals present with clusters of episodes. Some patients may experience increasingly frequent episodes along with an increase in disease severity. Some patients undergo a major depressive occurrence and then experience a subsequent one without full recovery from the first. |
| Likelihood of recurring depression: | About 50% of individuals who experience a singular episode will have another one. By extension, about 90% of individuals who have had three episodes are likely to have a fourth. Accordingly, the number of past events serves to predict likelihood of future events. The average number of lifetime episodes
is about five and about 5-10% of individuals initially diagnosed with major depressive disorder will later experience a manic episode. |
| Likelihood of remission of depressive episodes: | Depressive episodes may not exhibit remission or may remit completely or partially. Most of the time the individual return to "premorbid" level between episodes but about
20% to 35% of patients will show persistent residual symptoms with social or occupational impairment. Prior to the advent of antidepressant medication, depressive episodes could last about 12 months with frequent relapses. Since 1960 (after the introduction of antidepressant medications), about
25% of patients will relapse within the first six months of remission, an event may more likely if medication has been discontinued.30% to
50% of patients relapse in the first two years with 50% to 75% of patients relapsing within the first five years. The likelihood of relapse during early remission can be decreased substantially by maintaining patients on antidepressant medication for at least six months. |
| Depression and other psychiatric disorders: | Depression may be a characteristic of nearly all other psychiatric disorders. However, a diagnosis of depression is not appropriate if the episode is a part of bipolar disorder or schizoaffective disorder. |
| Depression and antidepressant medication: treatment approaches-- | Usually antidepressants are administered initially at a low dose which is increased over 7-10 days by which time the initial target dosage is attained. The dosage may have to be increased further in some patients to optimize clinical response.
In suicidal patients, extra care early in treatment is appropriate since behavioral activation may occur before improved mood. This setup may provide patients with sufficient energy to act on suicidal inclinations. |
| Evaluation of treatment response: | Following antidepressant treatment initiation, treatment response should be assessed every 3-4 weeks. Should recovery not be fully realized at that time, and in the absence of dose-limiting side effects, the dosage might be increased to the next appropriate incremental level. This approach may be followed until remission occurs, a dose-limiting side effect presents, or the upper end of the therapeutic range is attained. If
remission has not occurred, treatment may involve switching to a drug of a different therapeutic class. A partial response may argue for augmentation or combination therapy. |
| Antidepressant medication and treatment following achievement of therapeutic effect: | Following achievement of satisfactory therapeutic result, antidepressant medication is typically continued through a period of high vulnerability for relapse-which might be at least six months for continuation treatment. Long-term treatment may be consideration since more than 60% of depressed patients will eventually relapse, particularly of unprotected by medication on one hand and because feature episodes may be more severe. |
| Factors to be considered for antidepressant (maintenance) treatment for extended periods of time: | Long-term treatment (possibly years) might be considered if the patient is older than 40 years and has already experienced two or more prior depression episodes, the first episode occurred when the patient was at least 50 years of age, the patient had experienced already a history of three or more episodes of depression, or the patient was determined to have been depressed or dysthymic for at least two years prior to treatment. |
| Ending long-term maintenance therapy with antidepressant medications: | Should the patient be completely asymptomatic and not experiencing are expecting significant stressors, slow tapering of antidepressant drugs might be appropriate after at least five years of treatment. |