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This article was downloaded by: [Umeå University Library] On: 09 October 2014, At: 14:18 Publisher: Routledge Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Psychotherapy Research Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tpsr20 Linear and Nonlinear Changes in Mood Between Psychotherapy Sessions: Implications for Treatment Outcome and Relapse Risk Mark Thompson a , Larry Thompson a , Dolores Gallagher- Thompson a & Palo Alto a a Department of Veterans Affairs Medical Center , Stanford University School of Medicine , California Published online: 25 Nov 2010. To cite this article: Mark Thompson , Larry Thompson , Dolores Gallagher-Thompson & Palo Alto (1995) Linear and Nonlinear Changes in Mood Between Psychotherapy Sessions: Implications for Treatment Outcome and Relapse Risk, Psychotherapy Research, 5:4, 327-336, DOI: 10.1080/10503309512331331436 To link to this article: http://dx.doi.org/10.1080/10503309512331331436 PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/ page/terms-and-conditions

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Page 1: Linear and Nonlinear Changes in Mood Between Psychotherapy Sessions: Implications for Treatment Outcome and Relapse Risk

This article was downloaded by: [Umeå University Library]On: 09 October 2014, At: 14:18Publisher: RoutledgeInforma Ltd Registered in England and Wales Registered Number: 1072954Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK

Psychotherapy ResearchPublication details, including instructions for authors andsubscription information:http://www.tandfonline.com/loi/tpsr20

Linear and Nonlinear Changes inMood Between PsychotherapySessions: Implications for TreatmentOutcome and Relapse RiskMark Thompson a , Larry Thompson a , Dolores Gallagher-Thompson a & Palo Alto aa Department of Veterans Affairs Medical Center , StanfordUniversity School of Medicine , CaliforniaPublished online: 25 Nov 2010.

To cite this article: Mark Thompson , Larry Thompson , Dolores Gallagher-Thompson &Palo Alto (1995) Linear and Nonlinear Changes in Mood Between Psychotherapy Sessions:Implications for Treatment Outcome and Relapse Risk, Psychotherapy Research, 5:4, 327-336,DOI: 10.1080/10503309512331331436

To link to this article: http://dx.doi.org/10.1080/10503309512331331436

PLEASE SCROLL DOWN FOR ARTICLE

Taylor & Francis makes every effort to ensure the accuracy of all the information(the “Content”) contained in the publications on our platform. However, Taylor& Francis, our agents, and our licensors make no representations or warrantieswhatsoever as to the accuracy, completeness, or suitability for any purpose of theContent. Any opinions and views expressed in this publication are the opinions andviews of the authors, and are not the views of or endorsed by Taylor & Francis. Theaccuracy of the Content should not be relied upon and should be independentlyverified with primary sources of information. Taylor and Francis shall not be liablefor any losses, actions, claims, proceedings, demands, costs, expenses, damages,and other liabilities whatsoever or howsoever caused arising directly or indirectly inconnection with, in relation to or arising out of the use of the Content.

This article may be used for research, teaching, and private study purposes. Anysubstantial or systematic reproduction, redistribution, reselling, loan, sub-licensing,systematic supply, or distribution in any form to anyone is expressly forbidden.Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions

Page 2: Linear and Nonlinear Changes in Mood Between Psychotherapy Sessions: Implications for Treatment Outcome and Relapse Risk

Psychotherapy Research 5(4) 327-336, 1995

LINEAR AND NONLINEAR CHANGES IN MOOD BETWEEN PSYCHOTHERAPY SESSIONS: IMPLICATIONS FOR TREATMENT OUTCOME AND RELAPSE RISK Mark G. Thompson Larry Thompson Dolores Gallagher-Thompson Department of Veterans Affairs Medical Center, and Stanford University School of Medicine, Palo Alto, California

This study examined between-session changes in depressive mood among 91 older men and women receiving 16-20 sessions of outpatient psychotherapy. The majority of patients who recovered during treatment showed small between-session reductions in depression as measured by the Short Form Beck Depression Inventory. Still, nonlinearity in change was common, with most recovered patients experiencing two or more instances of major shifts toward mood worsening or improvement. The overall level of nonlinearity in change was positively correlated with recovery rate. Yet, high numbers of major mood shifts was linked with relapse risk. Patients who had relapsed at a 3-month follow-up ex- perienced twice as many instances of major mood shifts during therapy as those who maintained their recovery.

Although psychotherapy centers on promoting emotional and behavioral change, relatively little is known about how emotions change over the course of psy- chotherapy or the implications of different patterns of change (Barkham, Stiles, & Shapiro, 1993; Garfield, 1990; Mahoney, 199 1 ). Instead, traditional pretreatment- posttreatment statistical comparisons to assess psychotherapy outcome have focused on global and aggregate changes, ignoring individual variability in the rate and pattern of change. Indeed, an implicit assumption underlying these tests is that changes in mood and behavior are linear and occur at a relatively constant rate of change. Those who recovered during therapy are assumed to have experienced a steady rate of improvement, while those who did not recover remained in a constant symptomatic state.

The questionable nature of these assumptions have been highlighted by several commentators who advocate studying clinical change as a continuous process with multiple pathways to similar outcomes (e.g., Barkham, Stiles, & Shapiro, 1993; Francis, Fletcher, Stuebing, Davidson, & Thompson, 1991; Jones, Ghannam, Nigg, &

This work was supported in part by grant #MH37196 from the National Institute of Mental Health. Special thanks to Antonette Zeiss, Ph.D., and two anonymous reviewers for their comments on an

earlier draft of this manuscript. Correspondence regarding this article should be addressed to Mark G. Thompson, Ph.D., Depart-

ment of Quality and Utilization, Kaiser Permanente Medical Group, 1800 Harrison Street, Suite 410, Oakland CA 94612.

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328 THOMPSON ET AL.

Dyer, 1993; Stiles & Shapiro, 1989). Following this perspective, the present study set out to map the between session changes in self-reported mood among patients receiving psychotherapy for a major depressive episode. Specifically, the study examined six questions:

1. Does emotional change occur in a predominantly linear fashion for recov- ered patients?

2. When nonlinear shifts in mood do occur, do they appear to have beneficial or detrimental impacts on the amount or rate of improvement?

3. Do the majority of nonrecovered patients show a steady symptomatic state throughout therapy?

4. Are nonrecovered patients more likely to experience shifts toward worsen- ing mood and fewer shifts toward improvement in comparison with recov- ered patients?

5. Are individual differences in the rate and linearity of mood change related to other individual factors, such as demographic factors and clinical presenta- tion?

6. Does the pattern of change during therapy have implications for the post- treatment course of recovered patients?

The present study is a re-examination of the psychotherapy outcome of elderly depressed outpatients originally described by Thompson, Gallagher, and Brecken- ridge (1987). As they noted, there were no substantial differences in the effective- ness of cognitive, behavioral, or brief psychodynamic psychotherapies, as judged by pretreatment-posttreatment changes in diagnostic status or symptom inventory self-reports. The present study focused on the patterns of depressive mood change exhibited by patients, collapsing across therapeutic modalities, by examining re- sponses on the Short Form Beck Depression Inventory (Short BDI) that were completed at the start of each therapy session.

METHODS

Sample. Detailed sample descriptions and procedures are presented in Thompson, Gallagher, and Breckenridge (1987). The sample consisted of 91 men and women age 60 or over diagnosed as being in a current episode of major depressive disorder using research diagnostic criteria (RDC; Spitzer, Endicott, & Robins, 1978) on the basis of information obtained from the Schedule for Affective Disorders and Schizo- phrenia (SADS; Endicott & Spitzer, 1978). Pretreatment scores on the Hamilton Depression Scale (Hamilton, 1967) and the Beck Depression Inventory (Beck, Ward, Mendelson, Mock, & Erbaugh, 1961 ) were at least 14 and 17 respectively. The mean age was 67.07 years (SD = 6.15); 33% were men, and average length of education was 14.5 years (SD = 2.09). Most (82% ) were not employed outside of the home, and 58% were single through widowhood, divorce, or never having been married. One third of the sample reported no previous epidoses of depression, 52% reported one prior episode, and 17% reported two or more. Average duration of the current episode prior to seeking treatment was 2.8 years.

Patients were randomly assigned to cognitive, behavioral, or brief psy- chodynamic psychotherapy, and received 16-20 individual therapy sessions over a 4-month period. There were no significant differences between groups in therapy

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MOOD CHANGE 329

outcome. Fifty-two percent (n = 48) experienced full recovery, with an additional 20% ( n = 18) showing significant improvement. Twenty-eight percent ( n = 26) remained depressed at termination.

This study re-examines follow-up data gathered on 44 of the 48 fully recovered patients at 3, 6, and 12 months post-treatment. As described in detail by Gallagher- Thompson, Hanley-Peterson, and Thompson ( 1990), the SADS-Change interview (Spitzer & Endicott, 1977) was used to determine current diagnosis, and the Longitudinal Follow-up Evaluation (LIFE; Keller et al., 1987; Shapiro & Keller, 1979) was used to ascertain whether depressive episodes had occurred in the inter- val between evaluations. The cumulative relapse rate was 18% ( n = 8) at three months post-treatment; 36% ( n = 16) at six months; and 50% ( n = 22) at twelve months.

Meusures. The Short Form Beck Depression Inventory (Short BDI) consists of 13 items that were selected because of high correlations with both clinical ratings and the original standard form (Beck & Beck, 1972). Using the same 4-point format as the full BDI, items question the extent of: sadness, pessimism, sense of failure, dissatisfaction, guilt, self-dislike, self-harm, social withdrawal, indecisiveness, nega- tive self-image, work difficulties, fatigability, and appetite problems. As noted in studies of mixed-age adults, studies of the Short BDI among older adults have found it to have adequate internal consistency (Leahy, 1992; Scogin, Beutler, Corbishley, & Hamblin, 1988) and a similar factor structure to the standard scale (Foelker, Shew- chuk, & Niederehe, 1987; Leahy, 1992). It has been suggested that the severity of depression may be reflected on the Short BDI as follows: 0-4 (no or minimal); 4-7 (mild); 8-15 (moderate); and 16+ (severe) (Beck & Beamesderfer, 1974; Gal- lagher, 1986).

Physical health was assessed via self-reports of number of days sick during the past year, number of major medical conditions, number of medications, and evalua- tion of overall health (on a 4-point scale).

Data Analysis. The scores for each patient’s Short BDIs were plotted on the y-Axis against time or the number of sessions on the x-Axis. We refer to four parameters calculated for each individual patient using linear regression. First, the initial severity of depressed mood was measured as the intercept or constant in the regression equation. Second, the rate of change was measured as the slope of the regression line (B coefficient) in the units of the Short BDI Scale. The standardized Beta coefficient was used in all t-test calculations. Third, we calculated the root-mean square error (RMSE), which represents the residual variance not explained by the linear regression of Short BDIs on time. In effect, the RMSE is the standard deviation of residuals around the regression line. Following from Barkham and colleagues (1993), we viewed this as an indicator of the extent of nonlinearity in mood change. Fourth, for each patient, we conducted a t-test (it. , Beta divided by RMSE has a t distribution) of the hypothesis of no linear relationship between time and Short BDI scores.

In addition to examining the total extent of nonlinearity, we also calculated the difference between Short BDI scores at adjacent sessions for all patients in order to quantlfy nonlinear shifts in mood that occur between sessions. These 1,547 differ- ence observations had a highly peaked distribution with a mean of -.33 (SD = 3.33), indicating that the mean change in Short BDI scores between sessions was close to zero. We choose a cut-off of plus-or-minus 4 points to sign@ a significant or nonlinear change in Short BDI scores since this was beyond one standard deviation in the session-to-session change scores that were observed across patients. There-

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330 THOMPSON ET AL.

fore, for each patient we counted the number of nonlinear improvement shifts (i.e., instances during therapy when Short BDI scores dropped 4 or more points between sessions) and the number of worsening shifts (i.e., instances of increases of 4 or more points).

RESULTS

PATTERNS OF MOOD CHANGE AMONG RECOVERED PATIENTS

As shown in Figure 1, the recovered patients as a group (n = 48) experienced a steady and linear decline in Short BDI scores over the course of therapy, with minimal residual (nonlinear) variability. What is striking, however, are the sub- stantial standard deviations in Short BDI scores at any given session (M or SDs = 5.08). Therefore, individual plots and regression equations were examined for each patient. The mean slope of these individual plots was -.45 (SD = .36), meaning that recovered patients experienced approximately a half-point reduction in Short BDI scores between any given session. Sixty-nine percent of the individual plots had a significant linear t-test (p < . O l ) , meaning that the null hypothesis of no linear relationship between time and Short BDI decline could be rejected for the majority of the recovered patients.

Although a linear conceptualization of Short BDI change could be applied to the aggregate data and the disaggregate plots for the majority of recovered patients, there was considerable variability in patterns of change. This is best illustrated with individual cases, The course of recovered patient A (see Figure 2) matches a linear conceptualization of change. The patient experienced approximately a half-point reduction in Short BDI between each session. There was a significant linear relation- ship between time and Short BDI scores ( t = 7.34;p < .OOOl) and root-mean-square error or the standard deviation of the nonlinear residuals was low (RMSE = 1.35).

For other patients, although a significant linear trend in improvement can be

L"

15

S B D I

5

o ~ l l l l l l l l l l l l l l l l l l l I 2 3 4 5 6 7 8 9 10 I I I2 13 14 15 16 17 18 19 20

Session #

* +OneSD + - 0 n e S D - Mean

Intercept = 12.65

linear t = -25.62

RMSE -- p < .0001

Figure 1. Short BDI scores by session for patients recovered at post-treatment (n = 48).

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MOOD CHANGE 33 1

S B D I

15

10

5

0 I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 Session #

* ShortBDI

Figure 2. Short BDI scores by session for recovered patient A (cognitive therapy).

noted, there were substantial deviations from the linear trend during the course of treatment. For example, recovered patient B (see Figure 3) started with a similar Short BDI score as patient A, received the same therapy package, and experienced a similar mean rate of change. Yet, the course of patient B’s mood change was characterized by considerable residual variance (RMSE = 3.34). Most striking in this

20

W

15

S II D 10 I

5

I

~ E P ShortBDI

w Worsening Shifts

I Improvement Shifts

Intercept = 13.30

linear t = - 3.30

RMSE = p < .01

I 2 3 4 5 6 7 8 9 10 I ! 12 13 14 15 16 17 IX 19 20

Session #

Figure 3. Short BDI scores by session for recovered patient B (cognltive therapy).

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332 THOMPSON ET AL.

plot are the two instances of improvement shifts (at sessions 8 and 14) and the two instances of worsening shifts (at sessions 9 and 13).

Substantial drops in Short BDI scores were common among the recovered patients, with 90% experiencing one or more improvement shifts. As outlined in Table 1, the mean was experiencing 2.46 (SD = 1.97) such drops over the course of therapy. Nevertheless, significant increases were also common, with 65% of the recovered patients experiencing one or more worsening shifts at some point during therapy (M = 1.58; SD = 1.57). Therefore, although a notable minority of patients experience a steady and linear recovery, the more typical recovered patient in this study resembled patient B, whose course was characterized by an overall linear trend combined with both mild and substantial instances of nonlinearity.

RELATIONSHIP BETWEEN RECOVERY SLOPE AND OTHER CHANGE PATTERN VARIABLES

Among recovered patients, the rate of improvement for each individual's regression slope was inversely correlated with initial severity of the Short BDI reports (r = -.69;p < .OOl) and the extent of nonlinear residual variance (RMSE; r = -.50; p < .OO 1 ). Not surprisingly, among those who recovered, the more severe the initial depressive reports, the greater the rate of improvement that was ex- perienced. Interestingly, those who showed the greatest improvement (or the more negative slope) tended to have greater residual nonlinearity in mood change across sessions. This trend was noted when examining the RMSE, but not the other nonlinear indicators. Rate of improvement was not related to the number of im- provement shifts (r = -.17; NS) or worsening shifts (r = -.02; NS) patients ex- perienced.

PATTERNS OF MOOD CHANGE AMONG NONRECOVERED PATIENTS

As a group, nonrecovered patients (Major Depressive Episode at termination; n = 26) displayed a minimal decline in Short BDI scores across sessions (Slope = -.14). Patients who had dropped to Minor Depression at termination (n = 18) showed a slightly larger decline (Slope = -.29). Although the aggregate plots appear linear, again, there is substantial within group variation in Short BDI scores at any given session.

A review of the nonrecovered patients' individual plots suggests that, typically, symptom reports did not remain stable throughout therapy. Half (50%, n = 13) of the nonrecovered patients had a significant linear t association between time and

Table 1. Outcome Group

Mean Number of Improvement and Worsening Shifts by Psychotherapy

Recovered ( n = 48) Nonrecovered ( n = 26)

Improvement shifts

Worsening shifts

2.46 (SD = 1.97)

1.58 (SD = 1.97)

1.76" (SD = 1.47)

(SD = 1.47) 1.59h

"t (72) = -1.76, ns. ' t ( 7 2 ) = .28, n.s.

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MOOD CHANGE

- - 5 - - - - 0

333

I I I I I I I I I I I I I I I I I I '

S n D 1

25

W 20

15

10 1 1

- W

I

Short BDI Worsening Shifts

lmprovem t Shifts

Intercept = 18.98

RMSE =

Figure 4. Short BDI scores by session for nonrecovered case C (behavioral therapy).

Short BDI scores. Yet, even among those who could be characterized as experienc- ing a steady and linear symptomatic state, most experienced points of substantial nonlinearity. The vast majority (81 % ) of the nonrecovered patients experienced one or more significant worsening shifts, and surprisingly, 77% experienced one or more improvement shifts. A typical nonrecovered patient in this study resembles patient C (see Figure 4), whose course is characterized by a steady and linear symptomatic state, despite considerable mood flux at several points with approx- imately two instances of worsening shifts and two instances of improvement shifts during therapy.

As outlined in Table 1, there was no significant difference in the type or frequency of nonlinear shifts experienced by the recovered and nonrecovered patients. Patients were equally likely to experience substantial drops or increases in Short BDI scores, regardless of their ultimate outcome trajectory. This was the case during both the initial and latter stages of therapy and was also noted using different cut-offs to define significant Short BDI shifts.

INDIVIDUAL CHARACTERISTICS AND RATE AND PATTERNS OF MOOD CHANGE

No factors were identified which forecast individual variability in the pattern of change during therapy. The rate of mood change and the extent of linearity or nonlinearity in change were unrelated to individual differences in demographic characteristics (i.e., age, sex, marital status, or education), initial physical health, initial severity or duration of depressive episode, age of first depressive episode, or the number of prior episodes.

PATTERNS OF MOOD CHANGE AND RELAPSE RISK

Of the 44 recovered patients who participated in the follow-up study, eight ( 18% ) had relapsed within 3-months following termination. These relapsed patients

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334 THOMPSON ET AL.

had experienced sizeable nonlinear shifts during therapy. They had experienced more worsening shifts during therapy (M = 3.05; SD = 1.27) than those who maintained recovery (M = 1.28; SD = 1.43) (t(1,42) = 7.85, p < . O O l ) . Sur- prisingly, the relapsed patients had also experienced more improvement shifts during therapy (M = 4.00; SD = 2.39) than the nonrelapsed patients (M = 2.1 1; SD = 1.82) (t( 1,42) = 5 . 9 6 ; ~ < . O l ) . This finding was not repeated at the 6-month or 12-month comparisons of relapsed versus nonrelapsed patients. The other indicator of nonlinearity in mood change, root-mean-square-error, did not differentiate the relapsed and nonrelapsed patients at any follow-up, nor were initial Short BDI severity or rate of recovery related to relapse risk.

DISCUSSION

Mood change during therapy has both linear and nonlinear qualities. The traditional focus on group trends, pooling across patients, typically suppresses signs of nonlinearity. Indeed, the plots of Short BDI change summing across patients match a steady and linear conceptualization of change that would appear to justlfy pretreat- ment and posttreatment statistical comparisons. Yet, there are striking individual differences in the patterns of mood change among both recovered and nonrecov- ered patients that such analysis strategies ignore.

The findings of this and other studies (e.g., Barkham et al., 1993; Jones et al., 1993) suggest it may be worthwhile for psychotherapy research to attend to individual trajectories of change. Such descriptive and experimental research can increase our understanding of what constitutes “the road to recovery” for depressed patients. In this study, recovery was characterized by small reductions in self-report depression on a session-by-session basis. Therapists may also be reassured to have empirical support that instances of significant worsening can be expected over the course of therapy and do not necessarily forecast treatment failure. Indeed, in this study, the overall level of nonlinearity in change (not limited to major shifts) was positively correlated with recovery rate. Those who showed the greatest rate of improvement were the most likely to experience a “bumpy ride” or unsteady rates of depression reduction.

Nevertheless, at some yet unknown threshold, high nonlinearity in mood change, as characterized by frequent improvement and worsening shifts, may indi- cate vulnerability to early relapse. None of the eight patients who relapsed within three months of termination could be described as cyclothymic nor were they noted by their therapists to be emotionally labile. Nevertheless, they experienced approx- imately twice as many instances of sudden mood worsening and improvement during therapy in comparison to the patients who were able to maintain a longer recovery. Whatever forecasting value nonlinear shifts may have appears to be limited to a fairly brief period following termination, since the longer-term course of patients was unrelated to patterns of change. Future studies may wish to focus on identlfying the number, direction, intensity, and timing of shifts that may be most prognostic. Such information may aid in developing decision-trees for when to continue or terminate therapy and which patients may be the best targets for relapse-prevention programs.

Unfortunately, none of the particular measured patient characteristics or clini- cal indicators in this study were able to forecast response to psychotherapy or the pattern of such response. Although Thompson and associates ( 1987) had similarly

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MOOD CHANGE 335

found no factors which differentiated the diagnostic or symptom outcome of these patients, we thought the patterns of change variables might be more sensitive to possible individual differences. It would appear that either such prognostic links do not exist or could not be noted given the range of indicators observed in this sample.

Still, an essential goal of psychotherapy outcome research must be to identify factors that explain individual differences in the trajectory of emotional change during therapy. The existence of substantial nonlinearity in these trajectories may be a source of important information. We are currently investigating whether sub- stantial shifts in mood between sessions correspond to significant events within therapy sessions as well as the behavior of patients outside of therapy.

It may also be productive to focus on the emotional trajectories of nonrecov- ered patients. In this study, 77% of the nonrecovered patients experienced one or more instances of significant mood improvement, despite their intractable de- pressions. Understanding why such shifts occur but are then reversed may offer important clues into how to enhance the effectiveness of psychotherapy.

Researchers face a number of challenges in applying this methodology to psychotherapy research. Although we see value in tracking major shifts in mood and other behavioral symptoms, the cut-offs for determining what constitutes major versus minor shifts will necessarily be somewhat arbitrary. We defined a major shift as being a change that was one or more standard deviations beyond the mean of all between-session changes observed. This definition proved useful in this study, but requires replication.

Researchers may also wish to consider tracking mood change across specified time intervals in addition to or instead of session-by-session mood change. In this study, a formal research protocol ensured that there was little variability in number of sessions or the time frame across which these sessions occurred. However, when this is not the case, it may be difficult to compare change parameters across patients, since recovery slopes and numbers of major shifts will be calculated over different intervals.

The Short BDI appears to be a convenient and informative method of tracking mood change. Unfortunately, psychometric research on this scale has focused on its use as a one-time depression screening instrument. Therefore, additional data on the test-retest stability of the scale and its sensitivity to mood change as measured by other indicators is needed. Using the Short BDI also limits the focus to a global depressive index. Future studies may wish to track specific depressive symptoms or other emotions in order to identlfy how these parameters change independently or in tandem over the course of therapy.

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Received August 31, 1994 Revision Received February 20, 1995

Accepted March 6, 1995

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