Depression partial remission

Symptoms of a major depressive episode usually develop over days to weeks, but mild depressive and anxiety symptoms may last for weeks to months prior to the onset of the full syndrome. Left untreated, major depressive episodes typically last 6 months or more, but a minority of patients experience chronic episodes that can last for at least 2 years. Approximately two-thirds of patients will recover fully from major depressive episodes and return to usual mood and full functioning, whereas the other third will have partial remission and may continue to experience detrimental effects.3... 

The long-term course of MDD is highly variable but in approximately half of patients evolves into a chronic, relapsing illness. Untreated, a major depressive episode typically lasts about 6-12 months before resolving spontaneously. The emotional, physical, and social toll exacted during these months of depression can be tremendous. When the illness remits, most patients are able to function at their previous level however, 20% experience only a partial remission with persistent depressive symptoms that may last months or even years. 

A final type of minor depression is seen in those 15 to 20 percent of individuals who experience only a partial remission of symptoms following a major depressive episode. These people may clinically look dysthymic but are not. Typically, they do not have a lifelong history of low-grade or characterological depression. Usually... 

An adequate trial of antidepressant medication is defined as treatment with therapeutic doses of a drug for a total of 4 weeks. After 4 weeks of antidepressant treatment, patients can be divided into three groups those who have achieved a full response, those who have achieved a partial response, and those who have not responded. In the case of patients who achieve full remission, treatment should continue for a minimum of 4-6 months, or longer if the patient has a history of recurrent depression (see Maintenance Treatment of Major Depression later in this chapter). If a partial response has been achieved by 4 weeks, a full response may be evident within an additional 2 weeks without further intervention. If the symptoms do not respond at all, the dose should be increased, a different antidepressant should be used, or the therapy should be augmented with another medication (see Treatment-Resistant Depression later in this chapter). 

Lithium has been proven effective for acute and prophylactic treatment of both manic and depressive episodes in patients with bipolar illness (American Psychiatric Association 2002). However, patients with rapid-cycling bipolar disorder (i.e., patients who experience four or more mood disorder episodes per year) have been reported to respond less well to lithium treatment (Dunner and Fieve 1974 Prien et al. 1984 Wehr et al. 1988). Lithium is also effective in preventing future depressive episodes in patients with recurrent unipolar depressive disorder (American Psychiatric Association 2002) and as an adjunct to antidepressant therapy in depressed patients whose illness is partially refractory to treatment with antidepressants alone (discussed in Chapter 2). Furthermore, hthium may be useful in maintaining remission of depressive disorders after electroconvulsive therapy (Coppen et al. 1981 Sackeim et al. 2001). Lithium also has been used effectively in some cases of aggression and behavioral dyscontrol. 

Throughout the rest of this chapter, response and remission rates are used. Therefore, these concepts are briefly discussed here. Response is most often defined as a 50% or greater reduction in symptom severity as measured by a standardized rating assessment such as the Hamilton Depression Rating Scale (HDRS). The drawback to this approach is that response does not differentiate between partial and complete response, particularly when the initial symptom severity is high. Thus, a patient could be classified as a responder and still be quite symptomatic. In some instances, a patient could be classified as responder and still meet entry requirements for an antidepressant clinical trial based on their persistent symptom severity. 

As mentioned earlier, for certain patients there may be no class of antidepressants with better efficacy than the TCAs. For this reason alone, these medications remain a valuable part of the antidepressant armamentarium. When the dose of a TCA is adjusted based on clinic assessment of response, a TCA will produce at least a partial response in 60% to 70% of depressed patients and a full remission in 20% to 40%. When the dose is adjusted using therapeutic drug monitoring (TDM), the full remission rate may be higher. 

Very little work has addressed the topic of individual differences in response to sleep deprivation. It is clear that such differences exist total sleep deprivation produces remission of symptoms in depressed patients but does not have such large impact on mood in normals patients with chronic insomnia should suffer from significant partial sleep deprivation but actually seem less sleepy than normals when tested with the MSLT (48,49). It is certainly possible that individual differences in response to sleep deprivation are related to individual differences in sleep requirement. However, these individual differences may also be related to other intrinsic factors (such as level of central nervous system arousal, biological rhythms, or personality) or extrinsic factors (such as characteristic activity or light exposure patterns). 

Antidepressants do constitute the main cause for new sexual dysfunction seen in the average outpatient (Balon Harvey, 1995). Although various kinds of sexual dysfunction may be seen in the context of antidepressant therapy (Table 3.11), the most common manifestations seen in clinical practice are erectile dysfunction, partial or complete anorgasmia, and delayed ejaculation. Resolution of these side effects is critical to ensure treatment adherence and remission and to reduce the stress of the depressive episode on the patient s relationship with a spouse or significant other. When an antidepressant treatment achieves symptom remission but is complicated by sexual dysfunction as a side effect, several strategies have been used to deal with the problem, although the success of each varies from patient to patient (Table 3.12). 

Like other anxiety disorders, GAD is also relatively common, with a lifetime prevalence of about 5% and a 12-month prevalence of about 3% (Kessler et al., 1994). GAD occurs rarely in children, and although it may start early, it tends to increase in prevalence in the 30s and 40s, making it the most diagnosed anxiety disorder after midlife. It also tends to be chronic, with exacerbation and amelioration of symptoms over time, even with periods of remission. Women are affected twice as much as men, and the rates appear to increase very snbstantially in women once they reach their 40s. Psychiatric comorbidity is common, especially with depression and other anxiety disorders. GAD can be seriously disabling and can lead to substantial impairment in familial, social, and occupational functioning. As with other anxiety disorders, a partial genetic transmission model is suspected. 

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