12.1. Therapeutic Response

Before beginning an acute or index course of ECT, each patient should have a documented treatment plan, indicating specific criteria for remission. The type and severity of prominent symptomatology should be described. It is helpful for therapeutic goals to take into account the aspects of symptomatology that are expected to improve. For example, some patients with schizoaffective disorder present with relatively chronic forms of thought disturbance (e.g., delusions), with prominent superimposed episodes of affective symptomatology. In a number of these patients, ECT may ameliorate the affective component without influencing the chronic thought disturbance. Prolonging the ECT course because of persistent thought disturbance may result in unnecessary treatment. In contrast, many patients with mood disorder present with chronic dysthymia preceding a clear-cut episode of major depression. Some practitioners may be uncertain whether remission of a major depressive episode is associated with return to the chronic dysthymia or whether dysthymic symptomatology also responds to ECT. There is evidence that the extent of residual symptomatology shortly following ECT does not differ among patients with a double depression(i.e., major depression superimposed on dysthymia) and patients with major depression without a history of dysthymia (Prudic et al. 1993). Thus, in patients with double depression, basing treatment termination only on resolution of the major depressive episode may result in incomplete treatment, and possibly heighten the risk of relapse.

After the start of ECT, clinical assessments should be performed and documented attending physician or designee after every one or two treatments. To allow for clearing of acute cognitive side effects, it is preferable to conduct these assessments at least 24 hours following a treatment. Assessments should document changes in the disorder being treated with ECT, both in terms of improvement in the signs and symptoms that were present initially and the emergence of new symptomatology. Although infrequent, switches from depression to mania may occur during the course of ECT. In this context, it is important to distinguish between mania and a delirium with euphoria (Devanand et al. 1988b) (see also Section 5.3). Serial assessments of cognitive function may help in making this differential diagnosis.

In patients treated for catatonia, the nature of other symptoms may have been difficult to discern at pretreatment due to mutism or negativism. After catatonic symptoms improve with ECT, other aspects of psychopathology may become evident and should be assessed and documented. Other patients may have experienced delusions or hallucinations before or during the ECT course, but these symptoms may have been difficult to verify due to patient guardedness or other factors. With clinical improvement, additional symptoms may become apparent, impacting on future treatment.

Some practitioners find it useful to use a standardized rating instrument when assessing symptomatic change. Changes in rating scale scores over time are particularly helpful in determining whether the degree of improvement has accelerated, decelerated, or plateaued and in documenting the extent of residual symptomatology at the completion of ECT. For patients with major depression, the Hamilton Rating Scale for Depression (HRSD, Hamilton 1967) is a commonly used instrument. The 24-item version of the HRSD contains items assessing symptoms of hopelessness, helplessness, and worthlessness, features that are particularly common in patients receiving ECT. An alternative instrument is the Montgomery-Asberg Depression Rating Scale (MADRS) (Montgomery and Asberg 1979). For patients with psychotic disorder, clinician assessments of symptomatology may be performed with the Brief Psychiatric Rating Scale (Overall and Gorham 1962). The Young Mania Rating Scale (Young et al. 1978) may be used for patients with acute mania. It should be noted that the instructions used with instruments such as the HRSD traditionally assess symptomatology over the past week. Since symptomatic change with ECT is often rapid and requires more frequent assessment, it is useful to reduce the interval being examined to a few days.

Prior to ECT, clinician and self-report assessments of depression severity show only moderate correlation (Sayer et al. 1993). This discrepancy is largely attributable to a subgroup of patients who clinicians rate as moderately or severely depressed, but have low levels of symptomatology by self-report. These patients most commonly present with psychotic depression (Sayer et al. 1993). Following completion of ECT, the degree of agreement between self- and clinician-rated assessments is considerably greater. Some clinicians find that a formal self-report instrument is of supplemental value in documenting the effects of ECT on symptomatology. The Beck Depression Inventory II (Beck et al. 1996; Dozois et al. 1998) may be used, with the period being assessed modified from two weeks to at most one week. An alternative self-rating instrument is the Inventory Depressive Symptomatology (IDS-SR, Rush et al. 1985), which has the advantage of having a complementary clinician rated version. It should be noted, however, that self-ratings of depression seventy are supplemental, and should never substitute for clinician evaluations.

Before using ECT as a continuation treatment, the type and severity of residual symptomatology following acute phase treatment should be ascertained. As with acute phase treatment, the ECT physician should interview the patient before each continuation treatment to determine changes in symptoms and cognition. Emergence of symptoms suggestive of potential relapse should trigger consideration of changes in treatment frequency and/or technique.