Major depressive disorder
Controlled clinical studies show that 40 to 70 percent of patients with major depressive disorder (nonpsychotic nonmelancholic subtype) obtain a satisfactory response with either an antidepressant or one of the newer procedurally specified psychotherapies, such as cognitive-behavioral therapy or interpersonal therapy alone. Such success rates are clearly higher than the spontaneous remission rates observed in control groups of patients on waiting lists and surpass the gains observed in placebo groups or in pseudotherapy attentional control groups about 50 percent of the time. There is a paucity of data on more eclectic psychotherapies, and evidence gathered from randomized controlled trials of well-specified therapies may or may not be applicable.
Meta-analyses of early randomized controlled trials among outpatients with depression have shown relatively small additive effect sizes (
3,
32). Most of the early studies that used cognitive or behavioral therapies did not detect a statistically significant additive benefit of combined treatment (
33,
34,
35,
36). However, as noted above, interpretation based on these studies must be tempered by concerns about research methods and design sensitivity. More recently, a pooled analysis of nearly 600 outpatients with depression (
37) revealed that a combination of pharmacotherapy and interpersonal therapy was associated with remission rates that were about 15 percent higher than those associated with psychotherapy alone among patients with milder major depressive episodes. Although this is a modest effect, it would nevertheless have significant public health implications. Moreover, combined treatment was associated with a more substantial additive effect in a subgroup of patients with severe, recurrent depressive episodes. The major shortcoming of the study was the absence of a group that received pharmacotherapy alone.
In perhaps the most influential early study, DiMascio and colleagues (
38) studied outcomes with interpersonal therapy and amitriptyline, singly and in combination, compared with a low-contact control condition ("treatment on demand"). In terms of symptom measures, the two component monotherapies were superior to the control condition, and the combination was superior to monotherapies.
Results of a secondary analysis of the same data (
39) suggested that the three active treatment groups were comparably effective for the subgroup of patients who met research diagnostic criteria (
40) for situational, nonendogenous major depressive disorder. By contrast, combined treatment was superior to both monotherapies among the patients with nonsituational, endogenous depression. These findings essentially mirror those observed in the pooled analysis referred to above (
37). Thus it appears that a severity (endogenous) grouping can be used to select patients for whom combined treatment is likely to be more cost-effective than either pharmacotherapy or psychotherapy alone.
In another recent randomized study of outpatients with major depression, combined treatment was found to be more acceptable to patients and was associated with a significantly lower dropout rate and a significantly higher remission rate than medication alone (
41). The study used short-term psychodynamic supportive psychotherapy and a three-step successive medication regimen—fluoxetine, amitriptyline, and moclobemide, in that order, depending on intolerability or inefficacy—as pharmacotherapy.
Two small studies of hospitalized patients with depression produced evidence favoring a combined strategy over medication management (
42,
43). In a secondary analysis, Miller and colleagues (
44) observed a particularly large additive effect for combined treatment among patients with high levels of dysfunctional attitudes. Because patients with this pattern of negative thinking also tend to respond less favorably to cognitive-behavioral therapy alone (
45), one would presume that the advantage of combined treatment over psychotherapy alone would be evident. Although the data from controlled trials are sparse, it appears that the combination of cognitive-behavioral therapy and pharmacotherapy may be especially useful for patients with depression during and after an acute psychiatric hospitalization.
Three randomized controlled trials have been published of combined treatment among chronically depressed outpatients. Ravindran and colleagues (
21) found no additive benefit of a combination of group cognitive-behavioral therapy and sertraline in a study of 97 outpatients with dysthymia. The group cognitive-behavioral therapy was no more effective than placebo, which calls into question the efficacy of the psychosocial intervention.
Browne and associates (
46) conducted a randomized controlled trial among 707 patients with chronic depression who were randomly assigned to one of three treatment groups: interpersonal therapy alone, sertraline therapy alone, and a combination of sertraline and interpersonal therapy. Although all treatment modalities proved to be reasonably effective over a two-year period, sertraline alone or in combination was more effective than interpersonal therapy alone. The major finding in support of combined treatment was that patients had lower overall health and social service costs than patients receiving monotherapies.
In a multicenter trial of more than 650 patients with chronic depression (
9), combined treatment was associated with substantially better response and remission rates than both monotherapies, which had virtually identical outcomes. The study used the cognitive-behavioral analysis system of psychotherapy, an individual therapy specifically developed for the treatment of chronic depression (
47), as the psychotherapeutic intervention and nefazodone as pharmacotherapy.
The longer term effects of combined treatment have been documented in three studies. In the first study of continuation therapy, Klerman and colleagues (
48) did not detect significant benefits of combined treatment over pharmacotherapy alone in preventing relapses. However, there was a later emerging trend of a higher level of social adjustment in a subgroup of patients who received individual psychotherapy. Moreover, the study may have underestimated the benefit of the psychotherapeutic intervention, because all the patients had responded to amitriptyline before they began psychotherapy. (The study group was preselected for responsiveness to pharmacotherapy, not psychotherapy.)
Two more recent studies have evaluated the efficacy of combined treatment in the maintenance phase of recurrent depression. In both these studies, all patients received combined treatment during the acute and continuation phases. In the first study (
49), which involved 125 outpatients with highly recurrent major depression who were between the ages of 19 and 65 years, combined maintenance phase treatment—interpersonal therapy sessions plus imipramine—was not associated with better prophylaxis than imipramine alone during a 36-month blinded maintenance phase.
In the second study, 107 depressed outpatients aged 60 or older who had stabilized during the acute and continuation phases of treatment with nortriptyline and interpersonal therapy participated in a double-blind, placebo-controlled maintenance-phase study (
50). The patients who continued to receive combination treatment were less likely to have a recurrence than were those in either of the monotherapy conditions. Interestingly, the outcome of pharmacotherapy alone in that study was less robust than the results of Frank and colleagues (
49), which probably points to the relatively greater advantage of combined therapy when patients have higher inherent risk of recurrent depression.
Sequential treatment strategies have also been investigated. In one study, a three-month course of cognitive-behavioral therapy among 40 patients who had responded to pharmacotherapy but whose illness was not in remission was shown to have additive effects on residual depressive symptoms (
51). In follow-up reports, the group that received cognitive-behavioral therapy had a significantly better chance of discontinuing medication without relapse (
52) as well as a sustained decrease in the risk of recurrence (
53). Paykel and colleagues (
54) replicated these findings in a larger two-center study of 158 patients with incomplete remission who were taking antidepressants. The patients received 18 sessions of individual cognitive-behavioral therapy. The group that received cognitive-behavioral therapy in addition to pharmacotherapy had about a 50 percent reduction in relapse risk.
A third study investigated the efficacy of sequential cognitive-behavioral therapy treatment during the maintenance phase (
55). In that study, 40 patients whose illness was in full remission and who had a history of highly recurrent depression were randomly assigned to receive either 14 sessions of cognitive-behavioral therapy or supportive medication management during withdrawal of antidepressant pharmacotherapy. Again, the addition of cognitive-behavioral therapy was associated with a significantly reduced risk of recurrence over the next two years.
Bipolar disorder
There is a broad consensus that mania should not be treated with psychotherapy alone (
56). Specifically, the efficacy of several types of pharmacotherapy has been established for mania, whereas there is virtually no evidence that psychotherapy alone is effective. An exception may be made if a manic patient refuses pharmacotherapy. Even then, the ability of a manic individual to make informed treatment choices is always worrisome. In such cases, involuntary treatment, guardianship procedures, and mental health advance directives—depending on the jurisdiction—are some of the options.
Some of the information discussed in another paper in this issue of
Psychiatric Services (
57), about combined treatment for schizophrenia, could also be relevant to mania. Perhaps surprisingly, combined treatments for mania have received much less systematic inquiry than have those for schizophrenia, possibly because the therapeutic benefits of pharmacotherapy were overvalued until the early 1990s (
58). Eventually, it became clear that bipolar disorder is more often than not a recurrent and life-disrupting severe mental illness associated with profound morbidity and elevated mortality (
59). Furthermore, evidence of the effects of psychosocial factors such as stressful life events (
60), high levels of expressed emotion (
61), marital discord (
62), and social support (
63) on relapse rates among patients with mania led to the studies of various modalities of psychosocial interventions in relapse prevention.
In the first large study of combined treatment, Perry and associates (
64) evaluated a brief individual psychoeducation intervention (average duration of seven sessions). Apart from the information about the disorder and its treatment, patients were informed of the early warning signs of impending relapse and were provided assistance in developing relapse prevention plans. Compared with treatment as usual, the additional psychoeducational sessions were associated with significantly lower rates of relapses of manic episodes.
The second study (
65) evaluated a longer term model of family-focused therapy provided soon after discharge from inpatient treatment. All participants received pharmacotherapy as part of the study and were randomly assigned to receive either clinical management (N=70) or 21 sessions of family-focused therapy over a nine-month period (N=31). A preliminary report on the outcomes of nine patients who received family-focused therapy yielded promising results—one relapse, or 11 percent, compared with 14 relapses in a historical control group of 23, or 61 percent.
Results of the prospective study confirmed the benefit of family-focused therapy over the comparison condition for the first year, in terms of both fewer depressive relapses and lower levels of depressive symptoms. No significant association with risk of manic relapse was found. Adherence to medication regimens and reduced levels of expressed emotion were associated with outcome independent of treatment assignment. Thus, it seems that improved outcome with family-focused therapy was not mediated by medication adherence or lower levels of expressed emotion. However, the advantage of family-focused therapy was most pronounced among patients who lived in households with high levels of expressed emotions, particularly if the patient had not fully recovered from the index episode.
The third study examined a modified form of interpersonal therapy, adapted to help patients develop more stable social rhythms, known as interpersonal social rhythms therapy (IPSRT) (
66). All patients received appropriate pharmacotherapy for their index episodes. In addition, the study used a 2 × 2 sequential design for psychosocial intervention; half the patients received IPSRT for acute-phase management, and the other half received clinical management. During the maintenance phase of the study, half the patients in remission in each group continued to undergo the same treatment strategy, and half switched treatment strategies—that is, from IPSRT to clinical management or vice versa. As expected, IPSRT was not significantly associated with enhancement of patients' lifestyle regularity (
67). Moreover, the patients who received maintenance IPSRT experienced a significant reduction in depressive symptoms and an increase in the number of euthymic days (
68). However, IPSRT was not associated with improvement in acute-phase treatment outcomes or time to remission (
69,
70). Furthermore, discontinuation of acute-phase IPSRT was associated with an increase in risk of relapse, whereas the addition of maintenance IPSRT was not associated with a lower risk of relapse (
71).
Individual and group cognitive therapy also are being investigated as adjunctive treatments for bipolar disorder (
72,
73). Although results of controlled studies are pending, the results of preliminary studies suggest that these modalities have antidepressant effects (
74) and are likely to lower the risk of relapse among patients with mania (
75,
76,
77).
Taken together, the results of these studies provide support for the addition of focused psychosocial treatment for patients receiving pharmacotherapy for bipolar disorder. Family-focused and interpersonal therapeutic interventions appear to help with depressive symptoms. Psychoeducation and relapse prevention training may even reduce the risk of manic relapse.