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Consultation-liaison psychiatry:
stability and change over a 10-year-period
Albert Diefenbacher, M.D.*, James J. Strain, M.D.
Division of Behavioral Medicine and Consultation Psychiatry, The Mount Sinai-New York University Medical Center/Health Service,
New York, NY, USA
Abstract
Few long term studies have reported observations of changes over time with Consultation-liaison (C-L) populations. This is a
longitudinal observational study of a tertiary care psychiatric C-L–service over a ten-year-period (1988–1997) using a standardized
computerized clinical database to examine 4,429 consecutive referrals. Sociodemographic variables, relative consultation rates, reasons for
referral and psychiatric diagnoses, apart from a shift from adjustment disorders with depressed mood to major depressive disorders within
the depressive syndrome group, did not demonstrate significant changes during the study period. Levels of psychosocial and somatic
functioning of referred patients decreased. Changes occurred in the pattern of C-L–psychiatric recommendations, e.g., in the prescription
of antidepressants where tricyclic antidepressants were replaced by newer agents such as the selective serotonin reuptake inhibitors.
Consulting psychiatrists were more likely to refer to private psychiatrists to follow patients, and more patients were transferred to inpatient
psychiatric units. Due to a decrease in length of stay over the ten year observation period, the correlation oflagtime (the time from admission
to the hospital until referral to C-L psychiatry) and length of stay decreased from very strong to moderate. © 2002 Elsevier Science Inc.
All rights reserved.
Keywords: Longitudinal study; C-L psychiatry; Lagtime; Length of stay; Referral patterns
1. Introduction
Consultation-liaison (C-L) psychiatry allies with nonpsy-
chiatric physicians in general hospital and primary care
settings in the treatment of patients with psychiatric and
somatic comorbidity. Psychiatric comorbidity in somatic
patients is recognized as a major risk factor for impaired
somatic treatment outcomes, longer length of stay (LOS),
and increased rehospitalization, thus consuming greater
health care resources when compared to somatically ill
patients without psychiatric comorbidity [1–6]. Although it
is well known that longitudinal studies of the work done by
C-L psychiatric services may assist in the establishment of
priorities in teaching, research, and development of person-
nel [7] (as they may help elucidate changes in reasons for
referral, lagtime and LOS of patients referred, and in rec-
ommendations for interventions) a literature search shows
that few such research efforts have been published in the
last two decades [7–18].
Seven examined periods of three or more consecutive
years [7–14], two covered periods in the 1970s [7,8], five
reported consultation cohorts in the 1980s [9–14], with one
excluding consultations to patients aged over 64 years [11],
and two restricted to psychogeriatric services [9,13]. Ander-
son and Philpott [9] did review a psychogeriatric consulta-
tion service over an eight-year consecutive period. Most of
the other studies compared two or three nonconsecutive
half- or one-year-periods [15–18,18a], with three of them
examining a one-year-period in the 1990s [17–18,18a]. Li-
powski and Wolston compared two five-year periods (with
cumulative data) [7]. These studies reported a preponder-
ance of patients referred with organic mental and depressive
syndromes, but rarely referrals of patients with schizophre-
nia. They also revealed an increase in patient referrals over
the years. Secondary to an increase in overall hospital ad-
missions (as a consequence of reduced LOS), some, on the
other hand, reported that the relative consultation rate (the
proportion of patients referred relative to all hospital admis-
sions), decreased (from 5.8% to 2.8% [8]).
However, these studies did not have the advantage of a
common diagnostic taxonomy, e.g., DSM-III R, with its
operationalized diagnostic criteria [14]; nor did they have a
* Corresponding author. Tel.:�0049-30-5472-3140; fax:�0049-30-
5472-2913.
E-mail address: a.diefenbacher@keh-berlin.de (A. Diefenbacher).
General Hospital Psychiatry 24 (2002) 249–256
0163-8343/02/$ – see front matter © 2002 Elsevier Science Inc. All rights reserved.
PII: S0163-8343(02)00182-2
standardized documentation of core variables which had
been defined with training manuals for the C-L psychiatrist
to increase reliability and validity of the data. Furthermore,
there was a lack of: 1) prospective data collection and
documentation; 2) standardized documentation of interven-
tions recommended by the C-L psychiatrists; 3) structured
databases to collect salient variables in a standardized man-
ner; and 4) a sufficient observational period to elicit poten-
tial changes over time. With the exception of Paddison et al.
[12], data examined were retrospectively collected. Another
exception was the prospectively organized data collection in
accordance with a structured database employed by the
multisite European Consultation Liaison Workgroup that
collated data from C-L psychiatric services in twelve Euro-
pean countries in the early 1990s, but it was restricted to one
year [19]. No reports examined the development and evo-
lution of inpatient C-L psychiatric services during the
1990s, during which time developments had confronted
core beliefs, e.g., the possibility of C-L psychiatrists to
reduce LOS of patients referred [20]. And, perhaps as a
consequence, shifts occurred towards the opportunities of
C-L psychiatry in primary care settings which in themselves
developed vigorously during that decade [21].
Against this background, the present study examines the
development and evolution of a C-L psychiatric service
over a ten-year-period (1988–1997), an epoch during which
seminal changes occurred in the health care sector. The
intent of this study was to examine changes in: 1) referral
patterns and psychiatric diagnoses; 2) recommendations
made by the C-L psychiatrists; 3) disposition status post
medical/surgical hospitalization; 4) delays from admission
to hospital until referral to C-L psychiatry (lagtime); and 5)
LOS of patients referred to a C-L psychiatric service.
2. Materials and methods
This is a longitudinal observational study of the devel-
opment of a C-L psychiatric service at a tertiary care uni-
versity-affiliated teaching hospital, the Mount Sinai–NYU
Medical Center/Health Service in New York, NY, USA.
Data were collected prospectively on 4,429 consecutive
inpatient consultation requests over a ten-year-period
(1988–1997). Details of the study site, the Mount Sinai
Hospital (MSH), and the Division of Behavioral Medicine
and Consultation Psychiatry (BMC) of the Department of
Psychiatry at MSH have been published previously [23,24].
The 1,200 bed hospital has approx. 34,000 admissions per
year. The Division of BMC was staffed with four full time
attendings, two PGY 4 residents who worked three-fourths
time, and one full time clinical nurse specialist in psychia-
try. The consultation service staffed by PGY-4 residents
answered all consultations except those to liaison units, e.g.,
transplantation, otolaryngology, obstetrics and neurology,
where the Division’s attendings covered and documented
the consultations.
Throughout the study period, a microcomputer software
program with a standardized documentation system (MI-
CRO-CARES [www.microcares.com] clinical database sys-
tem [25]) was employed. This is an internationally distrib-
uted computerized C-L psychiatric database, tested,
enhanced and made more user friendly with advanced op-
erating systems over a 15-year period of development.
Computerization allows the systematic collection of clinical
data with a set of predefined variables. It allows ready
access for consultants to the archive of patients previously
seen, and the generation of data sets to examine character-
istics and treatment which may effect clinical decisionmak-
ing. Profiles of consultant patient cohorts are immediately
and systematically available to discern the teaching experi-
ence of each resident in training [25]. The MICRO-CARES
clinical database system has been utilized in a number of
individual and multisite studies [26–29]. The structured
database which guides the collection of relevant data ele-
ments prospectively (assisted by scoring guidelines) con-
sists of five genres of variables: 1) demographic; 2) reasons
for referral; 3) DSM-III R diagnostic ratings on five axes
(including ICD-9 medical diagnoses); 4) interventions (psy-
chological, behavioral, diagnostic and pharmacological);
and 5) hospital process variables, e.g., number of follow
ups, lagtime, LOS, discharge disposition. Six Axis I or II
psychiatric diagnoses could be recorded. Psychiatric diag-
noses were made by the consulting psychiatrist according to
DSM III-R. Psychosocial Axis V - the global assessment of
functioning one month prior to hospital admission, was
measured with the Global Assessment of Functioning
(GAF)-Scale [30]. Functional activities of daily living one
month prior to hospital admission and at termination of the
consultation were measured with the Karnofsky Perfor-
mance Scale [22]. Both instruments were completed by the
consulting psychiatrist.
To enhance and control reliability, an instruction manual
and glossary were constructed to train faculty and residents
responsible for performing consultation to ensure a standard
lexicon and operating procedure for acquiring, coding and
recording data. Procedures for checking adherence to glos-
sary definitions and accuracy of data entry were in place and
supervised in weekly staff meetings, ongoing training exer-
cises, and weekly consultant senior faculty supervisory ses-
sions. Special attention was given to reviewing each struc-
tured database sheet with each consultant, especially the
diagnosis, in order to enhance the quality of the data [31].
2.1. Statistical analysis
All data were checked for systematic errors by the au-
thors. Statistical procedures included descriptive statistics
for demographic variables, reasons for referral, diagnostic
characteristics and recommendations and interventions with
�2 analyses for categorical dependent variables and one-
way analyses of variance for dimensional dependent vari-
ables. Bonferroni corrections were used and statistical sig-
250 A. Diefenbacher, J.J. Strain / General Hospital Psychiatry 24 (2002) 249–256
nificance was set at a level of P�.005% [31a]. Pearson
product-moment correlations (Pearson’s r) were calculated
for associations between lagtime and LOS. All statistical
tests were two-tailed. Analyses were conducted using the
SPSS version 8.0 for Windows on personal computers [32].
3. Results
3.1. Sociodemographic variables
Sociodemographic variables remained constant over the
ten-year-period. Mean age of C-L-patients was 52.2 (SD
18.8) years, the proportion of patients between 66 and 75
years old and those 76 years and older remained 14%, and
13.5% respectively. With regard to demographic factors the
patients were: female 54.1%, married 28.9%, full- or part-
time employed 14.4%, admitted from home 89.3%, and
living alone at the time of admission to the hospital 29.9%.
Over the whole study period, an average percentage of
50.3% of the patients were referred from internal medicine,
infectious diseases and nephrology, 19.2% from the depart-
ments of surgery, orthopedics, ENT, neurosurgery and car-
diac surgery; 2.9% of referrals came from transplantation
services, 5.4% from neurology and 4.4% from OBGYN.
An average of 446 patients were referred each year from
the non liaison hospital units (range 292 to 523). This latter
number—523—was nearly twice that reported by Paddison
et al. (1981–1986) [12], when the average referral was 244
patients per year. The consultation rate fluctuated between
0.9% and 1.7% during the study period.
3.2. Reasons for referral and diagnostic assessment
Reasons for referral, as stated by the referring physician,
remained constant throughout the observation period, and in
the following order: “depression” (range 12.6%–18.3%);
“behavior management/agitation” (8.3%–13.3%); “ judg-
ment/informed consent/Against Medical Advice” (6.9%–
11.1%); and, “suicidal risk/attempt assessment”
(5.8%–10.1%). With regard to the urgency status of the
referrals a reduction occurred in the “ routine” (45.6% to
12.7%), with an increase in “same-day” (45.6% to 73.9%)
(�2�222.063, df�18, P�.000). “ Immediate” referrals, i.e.,
within 1 h after consult request, remained constant (14.2%).
Organic mental disorders (OMD), i.e., deliria, followed
by dementias and substance induced OMD, accounted for
the majority of Axis-I-diagnoses (40.1%). The second larg-
est group (28.1%) were the depressive disorders including
the adjustment disorders with depressed mood (AD). Within
this group, the AD diagnoses decreased by half (29.8% to
13.5%, in 1988 and 1997, respectively), while other depres-
sive disorders doubled (6.4% to 14.7%) (�2�8.539, df�1,
P�.004).
Substance use disorders remained in the third place
(8.5%). Schizophrenia and bipolar disorder diagnoses were
seldom assigned, as was the statement of “no Axis-I diag-
nosis” (4.7%, 1.7% and 6.4%, respectively).
Mean GAF-scores tended to decrease from 67 (SD 16.1)
to 59 (SD 18.6) (r2�.533, df�8, F�9.14, P�.016), and the
level of somatic functioning during the one month prior to
admission (Karnofsky Performance Scale [22]), as esti-
mated during the first consultation visit, also tended to
decrease over the ten year period (65 in 1988 to 55 in 1997,
r2�.419, df�8, F�5.77, P�.04).
3.3. Psychosocial recommendations and interventions
Psychological interventions, e.g., counseling, psycho-
therapy, patient education -the most frequent intervention
(73.7%) - and behavior management (22.1%) remained sta-
ble. Nonmedical consultations, e.g., referrals from C-L psy-
chiatry to social work nearly doubled (19.9% to 37.1%;
�2�188.164, df�9, P�.000).
3.4. Biological recommendations and interventions
A steady increase in the recommendation for laboratory
tests occurred (20.7% to 57.4%; �2�284.253, df�9,
P�.000). The recommendation of psychotropic drugs
tended to increase from the first to the second half of the
observation period (39.1% to 49.2%) (�2�7.616, df�1,
P�.006). The development of the prescriptions for selective
serotonin reuptake inhibitors (SSRIs) and two common tri-
cyclic antidepressants (TCAs), amitriptyline and nortripty-
line are shown in Fig. 1.
At the end of the 10 year observational period, both
TCAs are seldomly prescribed and virtually replaced by
SSRIs, first, beginning in 1989, with fluoxetine, then in
1993 by paroxetine and sertraline.
During the course of the study the percentage of patients
receiving a diagnosis of major depressive disorder (MDD)
approximately doubled, while the percentage diagnosed as
adjustment disorder with depressed mood (AD) was re-
duced by half, so that by 1996–1997 the frequency of these
diagnoses was equal (in 1996: MDD n�72, AD n�70; in
1997: MDD n�62 and AD n�57, respectively).
Over the entire 10 year period 34.1% of those with
MDD, and 8.6% of AD patients got an antidepressant rec-
ommended (�2�122.998, df�1, P�.000). Recommenda-
tions for antidepressants for both patient groups taken to-
gether increased from 11.9% to 32.8% (�2�28.105, df�9,
P�.001). This increase occurred concurrently with the in-
crease in the numbers of patients diagnosed with MDD,
while the number of AD patients diagnosed as such and
prescribed antidepressants remained the same (�2�14.259,
df�9, P�.113).
3.5. Hospital process variables
Over the entire study period, total time (initial and follow
up) per consultation episode remained stable (2–3 h).
251A. Diefenbacher, J.J. Strain / General Hospital Psychiatry 24 (2002) 249–256
Within this time frame, the number of follow-ups performed
by the psychiatric consultant increased from 2.9 (SD 3.9) to
4.9 (SD 7.2) (F�9.14, df�9, P�.000).From the beginning
to the end of the study period, obtaining information from
primary care increased (38.1% to 83.3%; �2�431.048,
df�9, P�.000) as did after care referrals (31% to 62%;
�2�126.070, df�9, P�.000). Both proportions of patients
transferred to a private or other psychiatrist, or admitted to
a psychiatric inpatient unit, increased (from 1.5% to 10.5%,
and from 2.2% to 14.5%, respectively; �2�435.249, df�36,
P�.000).
3.6. Lagtime and LOS
LOS and lagtime results (Table 1) and the mean LOS of
all MSH patients are presented (Fig. 2). The mean LOS of
all patients admitted to MSH was 8.98 days in 1988 and
6.94 days in 1997. During the same time the LOS of C-L
patients was reduced (25.7 to 13.4 days; F�10.180, df�9,
P�.000) (Fig. 2). Lagtime as well decreased (10.0 to 7.8
days; F�5.862, df�9, P�.000). Mean lagtime of C-L-
patients (10.3 days [SD 26.6]) was longer than mean LOS
(8.2 days) of all MSH inpatients for the entire 10-year
period: throughout the study period patients were referred
late into their hospitalization for psychiatric consultation.
The correlation between lagtime and LOS was high in 1988
(r�.719), but evidenced a decline to moderate correlation
by 1997 (r�.361) (Table 1) (after logarithmic transforma-
tion of lagtime and LOS, to account for the skewness of
these variables, statistical analyses yielded similar results).
4. Discussion
To our knowledge this is the longest period (1988 -
1997) of evaluation of consecutive referrals to a C-L psy-
chiatric service reported in the literature, and the first study
extending into the late 1990s on a consecutive per annum
basis when enormous changes were occurring in the sys-
tems and practice of medicine. Limitations inherent to sin-
gle site observational studies are well known and the results
may not be generalizable. Questions of reliability and va-
lidity of the data emanating from clinical encounters in
contrast to research populations is also well known. The use
of the medical record for research has been a standard in
observational studies. The advantage of this investigation is
that the medical record employed—the consultation
record—has been designed to heighten reliability and va-
lidity. Training sessions, including manuals, supervision
and review by senior attending psychiatrists occurred with
every case and every consultation recording form. Further-
more, the data were recorded prospectively. The sociode-
Fig. 1. C-L-Psychiatric Recommendations of Antidepressants (1988–1997).
Table 1
Correlations of LOS and Lagtime for MSH C-L patients (1988–1997)
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 Total
LOS (days) 25.7 28.3 19.9 29.5 26.6 22.0 22.1 17.2 15.3 13.4 21.4*
(SD 33.0) (SD 40.6) (SD 19.2) (SD 60.5) (SD 35.1) (SD 33.1) (SD 37.4) (SD 28.4) (SD 20.6) (SD 15.9) (SD 33.8)
LAGTIME (days) 10.0 13.0 10.2 15.6 12.7 11.4 8.5 6.3 6.8 7.8 10.3**
(SD 18.3) (SD 30.3) (SD 17.4) (SD 45.5) (SD 25.2) (SD 32.4) (SD 21.5) (SD 11.8) (SD 18.8) (SD 23.2) (SD 26.6)
Correlations (Pearson’s r)
LOS* LAGTIME (r) .719** .871** .699** .900** .487** .519** .665** .370** .509** .361** r � .773†
NB. The patient group whose LOS was not available did not differ statistically significant from the rest with regard to age and sex. * Differences between
years are statistically significant p � .000 (* F � 10.180; ** F � 5.862); † correlations are significant at p � .01 (two-tailed).
252 A. Diefenbacher, J.J. Strain / General Hospital Psychiatry 24 (2002) 249–256
mographic characteristics of the patients in this study ap-
proximate the characteristics of those reported usually by
psychiatric C-L services [24,33,34].
4.1. Constants
Although fluctuating, the consultation rate for the tenure
of the study was 1.2%, which is similar to that reported by
other investigators [19,33,34]. The primary reasons for re-
ferral also remained constant: “depression” and “behavior
management/agitation” , indicating the need to receive as-
sistance in managing patients whose aberrant behavior is
prone to impede the medical treatment process [35,36].
And, a constant proportion of 27.5% of patients 66 years
and older underlines the importance of psychogeriatric con-
sultation and a need for relevant competencies in the acute
care general hospital inpatients [9,13,38]. The examination
of psychiatric diagnoses highlighted their consistency dur-
ing a ten-year period. This finding is also consistent with
numerous reports from C-L researchers over the last several
decades [7–19,37]. It is somewhat surprising that substance
abuse, or the organic affective disorders, were not more
frequent with the surge in the numbers of aged and those
with HIV in the general hospital. Patients referred mani-
fested a slight decrease in their psychosocial functioning
(GAF Scale) during the year prior to the index-admission as
the study progressed. Their need for medical treatment and
intensity of assistance during the month prior to admission
(Karnofsky Performance Scale) as well slightly increased
over the course of the 10-year study. This underscores that
C-L psychiatrists evaluate and treat patients with significant
morbidity: the referred patients are not the “worried well”
whose referral to psychiatry may be regarded as merely
optional [1,11,51].
4.2. Changes
Interesting changes were observed related to the evolu-
tion in the health care system. While LOS of all patients at
MSH decreased on the average two days over the study
period, the LOS of C-L patients was shortened by 12.3 days
(Fig. 2). In comparison, the reduction of lagtime was less
(2.2 days). Consequently, a reduction of the correlation of
LOS and lagtime occurred (r�.719 in 1988 to r�.361 in
1997). Handrinos et al. hypothesize that lagtime may be
only an associated variable of a patient’s LOS [39]. Our
longitudinal data would support this. It may be that the high
correlations found in earlier studies between LOS and
lagtime reflect the situation in the late 1980s [40,41]. There-
fore, it would not be a reduction in lagtime that leads to a
reduced LOS, but the former variable covaries with changes
in LOS. In a cross-sectional study comparing a German and
a North American C-L psychiatric service, it was observed
that lagtimes were similar, but LOS differed [24]. The
longitudinal observations of this study may suggest an un-
coupling of the correlation of lagtime and LOS. This would
underscore the fact that LOS is a complex variable [42], and
as such should be used cautiously as an outcome parameter
of C-L psychiatric interventions, especially when the mech-
anism of the intervention and its possible impact on “sub-
units” of LOS are not known [4]. The data from the current
study suggest that decreasing lagtime would not necessarily
decrease LOS, an early hypothesis in the sub-specialty of
C-L. Decreasing lagtime was also heralded as critical for
cost savings in that its decrease would, in turn, diminish
LOS (hospital days are one of the most costly medical
expenses) [44]. The concept that a reduction of lagtime
would result in a reduction in LOS was too simplistic.
It is against this background of reduced LOS of general
hospital patients in general and C-L patients in particular, as
observed in this study, that some of the changes at the
interface of C-L psychiatry with other treatment settings,
and within C-L psychiatric practice itself, are examined.
Obtaining information from external sources and providing
for aftercare referrals increased two to threefold towards the
end of the study period. Similarly, patients transferred to
psychiatric inpatient treatment increased from 2.2% to
14.5%. Hall and Frankel [43] report that one in five patients
seen by a C-L service require referral to an inpatient psy-
chiatric, medical-psychiatric, or substance use disorder unit
bed for proper management. At the same time, these trans-
Fig. 2. LOS of C-L patients (�) and all MSH patients (▫) (1988–1997).
253A. Diefenbacher, J.J. Strain / General Hospital Psychiatry 24 (2002) 249–256
fers would enhance patients’ satisfactionwith treatment and
generate revenue for the parent organization [43].
Despite shortened LOS of C-L patients, the total time the
consultant spent with the patient and the consultee did not
decrease. The mean time spent per consultation episode
(initial and follow up visits) remained the same during the
study period. Both the mean time spent per consultation
episode (two to three hours) and the number of visits per-
formed (three to five) are similar to data from the 1990s
[31,36], and from the 1980s [46]. It appears that C-L psy-
chiatrists have maintained a high value on regular follow
ups of their patients, which has been subscribed to by the
Academy of Psychosomatic Medicine Practice Guidelines
for Psychiatric Consultation in the General Medical Set-
ting, in which an average of two follow up visits per con-
sultation episode is recommended [6].
4.3. Recommendations and interventions
C-L–psychiatrists’ interventions demonstrated an in-
creasing complexity over time. While psychotherapeutic
and behavioral management are provided to the majority of
patients referred throughout the study, and intensified inter-
actions at the interface of other inpatient and outpatient
treatment facilities take place, C-L psychiatrists did increase
their biological recommendations: in approximately half of
all patients referred, laboratory tests and psychotropic drugs
were recommended (57.4% and 49.2% of all C-L–patients,
respectively.) And referrals for nonmedical consultations,
mostly social work, rose from 19.9% to 37.1%. It appears
that the C-L psychiatrist becomes more of a case manager
during the 1990s.
4.4. Possible effects on C-L psychiatrists’ self-image
Could these changes in daily clinical practice affect the
self-image of C-L psychiatrists? Ramchandani et al. [36], in
a study of characteristics of the consultation process in the
1990s, observe that the traditional “ in-depth” relationship
with our medical colleagues—from the perspective of edu-
cating them in a more holistic view of illness—has yielded
to a “broader” relationship with the hospital milieu, con-
sulting to the system rather than to referring physicians
alone. C-L–psychiatrists may be forced to act less like
physicians evaluating and treating a specific patient, and
more in the role of a systems manager. This may also be
viewed as moving from a pure consultation to that of the
liaison mode.
This movement away from the clinical situation and
patient involvement, for which they were trained, into a
more administrative role, may diminish psychiatrists’ feel-
ings of self worth. The value of psychiatric consultation in
the general hospital, according to Lyons and Larson [47],
must not only take into account the needs of patients and
hospital administrators, but also both positive (e.g., good
job performance) and negative feelings of the psychiatric
consultant due to job-related stress: contrary to the 1980s
period studied by Paddison et al. [12] at the same hospital in
which 38% of all consultations were “ routine” (to be per-
formed within 24–48 h), that percentage had decreased to
12.7%: now, 74% of the consults were to be performed the
same day.
4.5. Prescription of antidepressants
Finally, this work presents the longest observation of the
practice of prescribing antidepressants in a C-L psychiatric
setting. It demonstrates, as reported by an Australian C-L
psychiatric service [48], that in the 1990s TCAs are virtually
replaced by newer agents such as SSRIs. These were en-
thusiastically welcomed by C-L psychiatrists because of
their favorable side-effect profile as compared to TCAs,
especially important for their use in the medically ill. The
beginning of our study period coincides with the introduc-
tion of the first SSRI, fluoxetine, in the USA (1988), which
became the most frequently prescribed antidepressant by the
C-L service at MSH in 1990. Sertraline and paroxetine, two
shorter-acting SSRIs, were introduced in the USA in 1991
and 1992, respectively, and, in turn, by 1993 had replaced
the longer-acting fluoxetine as the most frequently pre-
scribed antidepressants in our study. Overall, the prescrip-
tion of antidepressants tripled to 32.8% by the end of the
study period. This, however, was also secondary to an
increase in the diagnoses of patients with major depressive
disorder (MDD), for 34.1% of whom an antidepressant was
prescribed, which was similar to other reports (41% in [48]).
Patients diagnosed with adjustment disorder (AD) were
prescribed antidepressants in 8.6%, also similar to reports
from an international multisite study (7.4% in [31]). Both
percentages, however, were lower than reported in an inter-
national study, with 59% of MDD and 17% of AD patients
having an antidepressant prescribed [27]. As aftercare re-
ferrals of patients doubled, one might assume that the low
number of MDD patients that had an antidepressant pre-
scribed, was due to delaying definitive treatment of depres-
sion until being placed in a psychiatric follow-up setting,
but we are not able to further support this with our data.
Our data do not explain the decrease in the diagnosis of
adjustment disorders as the study progressed (29.8% to
13.5% of all psychiatric Axis-I-diagnoses in 1997). Along
with the reported tendency of the levels of psychosocial and
somatic functioning to decrease during the course of the
study period, patients may have evidenced more severe
depression enhancing their referral. C-L physicians may
also have attempted to maximize the potential for reim-
bursement by utilizing major psychiatric diagnoses rather
than a subthreshold nomenclature like adjustment disorder
with depressed mood, that was less likely to be reimbursed
254 A. Diefenbacher, J.J. Strain / General Hospital Psychiatry 24 (2002) 249–256
[36,43]. It might reflect a change in diagnostic decision-
making by the C-L psychiatrists: the differential diagnosis
of MDD and AD in the medically ill remains a controversial
issue [27–31,49–50].
Another factor that may be operating is that when TCAs
were the primary antidepressants used, it was argued that,
due to the instability of the MDD diagnosis in the medical
setting, TCAs should only be used cautiously because of
their sideeffects and questionable antidepressant effective-
ness in the medically ill [28,29,49]. The advent of the SSRIs
has prompted a more widespread use of these newer agents
in the medically ill, with the possible consequence of a shift
to diagnosing MDD with increased frequency. With the
improved side-effect profile of newer agents, MDD is now
viewed as a more treatable disorder in the medically ill [48].
5. Conclusions
In sum, our study shows both constant features, as well
as tremendous changes within a psychiatric consultation
setting during a ten year study period into the late 1990s:
1. Referral patterns, psychiatric diagnoses, consultation
time, and relative consultation rates remained stable
and should still provide a major focus of teaching in
the consultation setting, as well as for the definition
of C-L psychiatry as a subspecialty.
2. The diagnosis of MDD increased, while that of AD
decreased. The overall percentage of depressed pa-
tients for whom an antidepressant was prescribed,
increased. This was accompanied by a rising pre-
scription of SSRIs that nearly completely replaced
the older TCAs by the end of the study period.
3. Interface issues, genuine to C-L psychiatry at all
times, became ever more important: Referrals to psy-
chiatric inpatient units and outpatient psychiatric fol-
low-up increased as well as the referral of patients
from C-L psychiatry to social work. This points to a
possible change in the professional role of C-L psy-
chiatrists needing to adopt more the function of a
systems manager.
4. LOS of C-L patients, though further reduced during
the last decade, still remain longer as compared to
other general hospital inpatients. Lagtimes for psy-
chiatric consultation patients still are equivalent to
the average LOS of all general hospital inpatients,which means that C-L psychiatrists even now are
called in for consultation rather late in the treatment
process. Reduction of LOS in sub-groups of C-L
patients in the general hospital hence may be a pa-
rameter for psychiatric intervention studies in gen-
eral hospital inpatients that should not be disregarded
[45].
Acknowledgment
The authors thank Dr. rer.nat. Martin Siegert, Statisti-
cian, from the Bundesinstitut für Arzneimittel und Mediz-
inprodukte in Berlin, for help and advice, and Monika Wolf,
Psychologist, Humboldt-Universität in Berlin, Institut für
Psychologie, for performing the statistical analyses.
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