Functional Impairment and Disability across Mood States in Bipolar Disorder
Eduard Vieta, Clinical Institute of Neuroscience, University Clinic Hospital of Barcelona. Villarroel, 170, 08036, Barcelona, Spain. E-mail: firstname.lastname@example.org
Background: Bipolar disorder (BD) represents a chronic and recurrent illness that can lead to severe disruptions in family, social, and occupational functioning. The severity of mood symptomatology has been associated with functional impairment in this population. However, the majority of studies have assessed global functioning without considering specific domains. The main objective of the current study was to assess specific life domains of functioning as well as the overall functioning in patients with BD across different mood states ([hypo] mania, depression, or euthymia) compared with healthy controls by the means of a standardized scale validated for BD.
Methods: The sample included 131 subjects with BD (68 in remission, 31 hypo [manic], and 32 depressed) and 61 healthy controls. The Functioning Assessment Short Test was used to assess overall and multiple areas of functional impairment (autonomy, occupational functioning, cognitive functioning, interpersonal relationships, financial issues, and leisure time).
Results: The results showed significant intergroup differences; depressed patients had the lowest functioning (48.03 ± 12.38) followed by (hypo) manic patients (39.81 ± 13.99). The euthymic group showed least impairment in functioning compared with the depression and (hypo) mania groups (11.76 ± 12.73) but still displayed significant impairment when compared with the healthy control group (5.93 ± 4.43).
Conclusions: This study indicates that depressive symptoms are associated with greater negative impact on psychosocial functioning than (hypo) manic symptoms. Further deficits in functioning seem to persist during remission. The results highlight the importance of aggressively treating depression and mania and the need to develop psychosocial interventions targeting to improve functional outcomes.
Bipolar disorder (BD) represents a major public health concern; the World Health Organization (WHO) ranks BD as the sixth leading cause of years lost due to disability in young adults . Individuals with BD incur higher health-care expenses, job absenteeism, and short-term disability payments than controls . BD can also carry a heavy personal toll, often being associated with severe impairments in outcomes and quality of life (QoL) [3–5].
Research into BD has been driven by the medical model; one consequence of this orientation is that treatment outcomes in BD have traditionally been assessed by the examination of clinical information, such as rates of treatment response or remission as measured by mania or depression symptom rating scales. More recently, however, there has been increasing emphasis on the need for additional measures to compliment symptomatic assessments; for example, Keck  has suggested that “functional outcomes are more meaningful measures of response to treatment for BD than are scores on various psychiatric rating scales.” Psychosocial functioning describes a person's ability to perform the daily life tasks and to engage in relationships with other people in ways that are gratifying to the individual and to others and that meet the needs of the community in which the person lives. The assessment of psychosocial functioning should ideally involve evaluation across one or more behavioral domains, such as the individual's ability to function socially or occupationally, or to live independently, with functional recovery typically being defined as restoration of normal role functioning in the domains under scrutiny [7,8]. It is now recognized that symptomatic and functional outcomes in BD are not synonymous. For example, in one oft-cited study of first-episode patients, Tohen and colleagues  reported that 98% of a sample of patients with BD achieved syndromal recovery within 2 years compared with only 38% achieving functional recovery (defined as the proportion of patients who regained occupational and living situations equivalent to those they held before their episode).
Mood symptoms have been significantly associated with functional impairment in BD . In general, symptoms of depression have been found to account for more variance in functioning than do symptoms of mania [11–13]. Using the Longitudinal Interval Follow-up Evaluation assessment method, data from a large follow-up study showed that increases in depressive symptom severity in patients with BD are associated with corresponding increases in psychosocial impairment . Depressive symptoms have shown to be associated with functional role impairment in multiple domains such as duties at work or school, responsibilities at home, and relationships with family and friends . Some clinical variables and neurocognitive impairments have also been related to poor psychosocial functioning [15,16]. Despite this growing body of data, a paucity of research investigating psychosocial functioning across mood states in BD persists. In addition, existing studies have not always used standardized scales for the assessment of functioning or have used self-reported scales that some researchers argue may be confounded by mood state or personality traits [11,17]. Finally, most previous research in this area has involved the assessment of global psychosocial functioning as opposed to the assessment of functioning within specific life domains. An understanding of which specific domains of psychosocial functioning are mostly impaired in patients with BD would be of clinical utility as such information could contribute to the development of interventions focused upon functional restoration.
There is a paucity of studies aiming to assess the functional impairment in all phases of BD. The present study was conducted to assess specific life domains of functioning as well as the overall functioning in patients with BD across different mood states ([hypo] mania, depression, or euthymia) as compared with healthy controls via the Functioning Assessment Short-Test (FAST). We also evaluated the FAST sensitivity to detect minimal differences in the severity of mood symptoms across the mood states.
The study represents a cross-sectional analysis of the baseline data collected for a longitudinal study of psychosocial functioning in patients with BD initiated in July 2007.
The sample was recruited via the Bipolar Disorders Program of the Hospital Clínic at the University of Barcelona (Spain). All enrolled patients received pharmacological treatment by their psychiatrist according to the program's protocols in a naturalistic manner. Inclusion criteria were age >18 years and fulfillment of DSM-IV criteria for bipolar I or bipolar II disorder. The sample was divided into three groups according to their scores on the 17-item Hamilton Depression Rating Scale (HAM-D) and the Young Mania Rating Scale (YMRS). Participants with a HAM-D score of 16 or greater were included in the depressive group (D). Subjects with a YMRS score above 12 were included in the (hypo) manic group (M). Subjects with a HAM-D score of 16 or greater and a YMRS score of 20 or greater were considered to be affected by a mixed state and were also included in the (hypo) manic group. Subjects with HAM-D and YMRS scores below 7 were included in the euthymic group (E). Patients exhibiting subsyndromal symptoms were excluded.
The healthy control group (C) included individuals with no psychiatric or neurological history and no first-degree family members diagnosed with BD sampled from the regional general population.
FAST scale, the objective variable aiming to evaluate the correlation of functionality changes by episode (acute patients and euthymic), was used to calculate the sample size. Our previous data suggest a correlation between euthymic/controls with a median of ±SD of 18.55 ± 13.19 and 5.93 ± 4.43, respectively. In base of this data and considering a confidence interval (1-α) = 95% with a precision level of 0.05 for the FAST means and assuming around 8% to 10% of dropouts among the study patients, we needed to recruit approximately 22 patients for each group.
Both the Structured Clinical Interview for DSM-IV Axis I and Axis II were administered to confirm diagnosis [18,19]. Sociodemographic, clinical, and pharmacological data were collected via a structured interview with the patient and examination of clinical records. The 17-item HAM-D and the YMRS were administered by trained raters to assess depressive and manic symptoms, respectively [20,21]. The FAST (see appendix at: http://www.ispor.org/Publications/value/ViHsupplementary/ViH13i8_Vieta.asp) was utilized to assess functional impairment. It is a valid and reliable instrument, easy to apply, and which requires a short period of time to administer (3–6 min). It was developed for the clinical evaluation of the main difficulties presented by psychiatric patients and has been validated in several languages for patients with BD . The FAST scale consists of 24 items that allow the assessment of six specific areas of functioning:
- 1Autonomy refers to the patient's capacity to do things alone and make his or her own decisions.
- 2Occupational functioning refers to the capacity to maintain an employment, efficiency of performing tasks at work, working in the field in which the patient was educated, and earning according to the level of the employment position.
- 3Cognitive functioning is related to the ability to concentrate, perform simple mental calculations, solve problems, and learn and recall new information.
- 4Financial issues involve the capacity of managing the finances and spending in a balanced way.
- 5Interpersonal relationships refer to relations with friends and family, involvement in social activities, sexual relationships, and the ability to defend one's own interests.
- 6Leisure time refers to the capability of performing physical activities (sport, exercise) and maintaining hobbies.
Items are rated using a 4-point scale where 0 = no difficulty, 1 = mild difficulty, 2 = moderate difficulty, and 3 = severe difficulty. The overall FAST score ranges from 0 to 72, where higher scores indicate greater disability, with a threshold score of 11 indicating the presence of significant disability . The FAST was administered within the same day of the symptomatic assessment by a trained rater who was blind to the participant's group allocation.
This study was approved by the Hospital Clínic of Barcelona Ethics Committee. After receiving a complete verbal description of the study, written informed consent was obtained from all the participants.
The statistical analysis was performed with the Statistical Package for Social Sciences (SPSS v.16 for Windows, SPSS Inc, Chicago, IL). The four groups (euthymic [hypo] manic, depressed, and healthy control) were compared regarding clinical and sociodemographic characteristics by using analysis of variance (ANOVA) and the chi-squared test, as appropriate. The mean total scores and subscores of the FAST were compared across the four groups using ANOVA, followed by the Tukey post hoc comparison procedure when significant main effects were present. All P-values were two-tailed and statistical significance was set at P < 0.05.
The sample comprised 68 euthymic BD patients, 31 in a hypo (manic) episode, 32 in a depressive episode, and 61 healthy controls. Demographic and clinical characteristics of the groups of patients and healthy controls are shown in Table 1. The patient groups showed significant differences with regard to severity of depressive symptoms (P = 0.001), severity of manic symptoms (P = 0.001), number of hospitalizations (P = 0.010), and Axis II comorbidity (P = 0.002). Significant differences were also observed between groups regarding the use of mood stabilizers and antidepressant agents (see Table 1).
Table 1. Clinical and demographic characteristics in patients and control group
|Age||48.06 ± 13.76||50.42 ± 16.23||49.47 ± 13.58||49.16 ± 17.66||0.18||0.909|
|Age at onset of illness||26.92 ± 10.40||29.64 ± 15.46||27.76 ± 10.96|| ||0.47||0.623|
|HAM-D||1.55 ± 2.10||8.10 ± 8.11||20.29 ± 4.68|| ||162.95||0.001|
|YMRS||0.93 ± 1.94||19.77 ± 7.42||2.94 ± 3.55|| ||216.55||0.001|
|Number of hospitalizations||2.05 ± 2.08||3.56 ± 2.26||3.29 ± 3.01|| ||4.86||0.010|
|Number of depressive episodes||7.02 ± 11.16||8.50 ± 8.52||6.91 ± 4.81|| ||0.22||0.806|
|Number of hypomanic episodes||5.32 ± 11.25||4.91 ± 6.67||2.64 ± 2.82|| ||0.69||0.502|
|Number of manic episodes||3.11 ± 4.68||4.79 ± 4.23||5.00 ± 5.89|| ||1.76||0.177|
|Number of mixed episodes||0.59 ± 1.03||1.32 ± 2.44||1.00 ± 1.16|| ||2.17||0.120|
|Number of total episodes||15.68 ± 21.64||19.82 ± 16.83||15.83 ± 10.85|| ||0.41||0.664|
|Number of suicide attempts||0.56 ± 1.15||0.56 ± 0.82||0.95 ± 1.16|| ||1.08||0.343|
|Male||34 (50.0)||15 (48.40)||11 (34.40)||26 (42.60)||2.43||0.488|
|University or postgraduate complete||23 (33.8)||9 (29.0)||12 (37.50)||15 (24.60)||2.12||0.548|
|Married||22 (33.8)||7 (26.90)||9 (36.0)|| ||5.55||0.476|
|Bipolar type I||48 (72.7)||26 (92.90)||19 (76.0)|| ||10.10||0.120|
|Lifetime history of psychotic symptoms||39 (60.9)||19 (79.20)||16 (69.60)|| ||2.72||0.257|
|Family history of affective disorder||31 (52.50)||12 (48.0)||17 (68.0)|| ||2.35||0.309|
|Lifetime substance abuse||43 (63.2)||24 (77.4)||18 (56.20)|| ||3.27||0.195|
|Rapid cycling||7 (11.10)||7 (29.20)||5 (20.80)|| ||4.29||0.117|
|Axis I comorbidity||29 (42.60)||18 (58.10)||17 (53.10)|| ||2.33||0.311|
|Axis II comorbidity||21 (30.90)||17 (54.80)||21 (65.60)|| ||12.19||0.002|
|Current medications|| || || || || || |
| Mood stabilizer||59 (86.80)||22 (71.0)||21 (65.60)|| ||6.76||0.034|
| Antipsychotics||38 (55.90)||21 (67.70)||14 (43.80)|| ||3.67||0.159|
| Antidepressants||20 (29.4)||4 (12.90)||14 (43.80)|| ||7.29||0.026|
| Benzodiazepines||33 (48.50)||17 (54.80)||16 (50.0)|| ||0.34||0.843|
Table 2 shows the total scores and subscores of the FAST across the four groups. Patients with depression (hypo) mania and euthymia experienced poorer overall functioning when compared with the healthy control group (D: 48.03 ± 12.38; M: 39.81 ± 13.99; E: 11.76 ± 12.73; C: 5.93 ± 4.43; P < 0.001). The depressive and (hypo) manic groups showed significantly poorer functioning compared with the euthymic and control groups across all domains. Examination of between-group differences illustrated that participants in the depressive group showed more impairment than those in the (hypo) manic group in autonomy (P < 0.001), cognitive functioning (P < 0.001), interpersonal relationships (P < 0.001), leisure time (P < 0.001), and overall functioning (P < 0.001). No statistically significant between-group differences were found in occupational functioning or financial issues. When euthymic patients were compared with the control group, findings were more favorable for the latter in autonomy (P < 0.001), occupational functioning (P < 0.001), cognitive functioning (P < 0.001), and interpersonal relationships (P < 0.001).
Table 2. Functional impairment across different domains in patient and control group
|FAST total||11.76 ± 12.73||39.81 ± 13.99||48.03 ± 12.38||5.93 ± 4.43||128.49||P < 0.001||D > M > E > C|
|FAST autonomy||2.19 ± 2.88||6.10 ± 3.62||8.00 ± 3.26||0.38 ± 0.99||72.64||P < 0.001||D > M > E > C|
|FAST occupational||6.13 ± 6.44||12.45 ± 4.92||12.81 ± 4.44||1.16 ± 2.09||58.78||P < 0.001||D = M > E > C|
|FAST cognitive||3.15 ± 3.10||7.64 ± 4.01||10.00 ± 3.35||1.00 ± 1.06||85.82||P < 0.001||D > M > E > C|
|FAST interpersonal relationships||3.88 ± 3.14||8.07 ± 4.20||11.22 ± 4.12||1.82 ± 2.56||66.02||P < 0.001||D > M > E > C|
|FAST financial issues||0.51 ± 1.26||2.00 ± 2.20||1.34 ± 1.79||0.18 ± 0.53||14.09||P < 0.001||D = M > E = C|
|FAST leisure time||1.90 ± 1.79||3.45 ± 1.95||4.84 ± 1.59||1.39 ± 1.29||36.66||P < 0.001||D > M > E = C|
The main objective of this study was to examine functional impairment across mood states in a well-characterized sample of patients with BD and healthy controls via scale validated for use in BD. The FAST is an interviewer-administered instrument that permits exploration of specific domains of functioning and disability. Higher functional impairment was observed in patients who were in a depressive episode, followed by patients in a hypo (manic) episode, and finally the euthymic group. Compared with the healthy control group, patients with BD in clinical remission still showed poorer psychosocial functioning.
Our findings are consistent with previous cross-sectional and longitudinal studies where the presence of mood episodes in BD has been strongly associated with poor functioning [14,23,24]. Judd and colleagues  have reported that each increment in depressive symptom severity for patients with BD I and II is associated with a corresponding increase in psychosocial impairment, with the strongest associations being observed between functional impairment and symptoms of mania in patients with BD type I. In other research, Simon and colleagues  observed that patients with depression or mania exhibited greater impairment than patients in remission, with symptoms of depression being associated with greater disability than symptoms of mania. Our results complement those of Simon and colleagues as we also observed that depressive symptoms led to a greater functional impairment than hypo (manic) symptoms, although patients with (hypo) mania showed poorer functioning than remitted patients and healthy controls. Other authors have also found a strong relationship between the severity of depressive symptoms and the level of functional impairment in this population [11,25,26]. Depression rather than mania may have a greater impact on particular areas of functioning such as social and daily activities , and work productivity measured as employment and days missed from work . Although in our study no differences were found in occupational functioning between patients with mania or depression, the latter showed fewer social interactions with friends and family, less interest or pleasure in the leisure activities, less autonomy to maintain duties, and worse cognitive functioning. Bipolar depression may have an insidious onset; however, the impact on life functioning is enduring. In comparison with the treatment of mania, which can often occur relatively quickly , the treatment of depression can be associated with longer times to recovery, with a chronic course holding the potential for greater deficits in psychosocial functioning.
We also observed that euthymic patients with BD experienced poorer psychosocial functioning than healthy controls. Our results confirm findings of previous studies that have suggested that patients with BD suffer from substantial functional impairment even in periods of remission [28–30]. Subsyndromal depressive symptoms have been consistently associated with poor psychosocial functioning [31–33]. In a recent study, we found that residual depressive symptoms, albeit minimal (HAM-D < 7), were strongly associated with occupational impairment and cognitive impairment in euthymic patients . It is worth mentioning that numerous studies have reported persistent neuropsychological deficits not only in acute but also in euthymic patients with BD . Cognitive deficits, especially verbal memory and sustained attention, have also been associated with poor psychosocial and occupational functioning [15,35]. Deficits in memory, attention, and planning may lead to impairment in social, interpersonal, and occupational functioning, and these deficits make it difficult to undertake occupational tasks or engage in interpersonal relationships . Furthermore, the number of episodes an individual experiences, particularly depressive episodes, seems to be a strong predictor of future recurrence and poor psychosocial functioning . It has been suggested that recurrent episodes may contribute to persistent brain changes and long-lasting biochemical changes; these changes may exert an effect on functioning even during periods of symptom quiescence [37,38]. Taken together, these data suggest that prophylactic treatments in BD should be complemented with the development of therapeutic interventions aimed at improving functional outcomes. Together with syndromal recovery, full functional recovery should be the goal of the treatment for this population.
Finally, we showed that the FAST permits the detection of differences not only between acute and remitted patients but also between depressive and manic ones. This was evident in all areas of functioning, except for the occupational functioning and financial issues. These preliminary findings suggest that the FAST could be useful in clinical trials in detecting minimal changes achieved by different treatments, including improvement and worsening of symptoms (depressive episode, manic episode). However, further larger longitudinal studies are required to validate the present findings.
There are several limitations that should be considered when interpreting the results of this study. First, the affected sample was recruited from a tertiary hospital; participants in the study are therefore likely to be weighted toward those with greater illness severity and may not be readily generalizable to the wider population of individuals living with BD. Second, we did not control for the impact of mixed subthreshold symptoms on functioning. Third, as we included hypomanic and manic patients in the same group analysis, such differences in symptom severity could represent a potential confounder. Fourth, this is a cross-sectional study that does not allow us to determine the direction of the relationship between mood symptoms and functional impairment. Longitudinal studies are needed to understand the cause-and-effect relationship between specific domains of functioning and clinical factors.
Despite the above-mentioned limitations, our results suggest that patients with depressive and manic episodes experience poor psychosocial functioning in distinct areas and that these deficits persist in an attenuated form during periods of remission. The results highlight the importance of treating both the symptoms of mania and depression aggressively, and also suggest that when patients are euthymic, treatment should focus on rehabilitative measures to improve functioning. Therefore, the development of psychosocial interventions aiming to improve functional outcomes in patients with BD, and potentially their QoL, represents an urgent challenge for future studies.
Source of financial support: This work was supported by grants from the Spanish Ministry of Science and Innovation, Instituto de Salud Carlos III (PI080180 and PI08/90094), CIBERSAM and the support of the Generalitat de Catalunya to the Bipolar Disorders. Group (2009 SGR 1022). One of the authors (Adriane R Rosa) is funded by the Spanish Ministry of Science and Innovation, through a “Juan de la Cierva” postdoctoral contract (JCI-2009-04329).