Bipolar Disorder in Primary Care: Clinical Characteristics of 740 Primary Care Patients With Bipolar Disorder
Abstract
Objective
This study aimed to describe the characteristics of primary care patients with bipolar disorder enrolled in a statewide mental health integration program (MHIP).
Methods
With the Composite International Diagnostic Interview (Version 3.0) and clinician diagnosis, 740 primary care patients with bipolar disorder were identified in Washington State between January 2008 and December 2011. Clinical rating scales were administered to patients at the time of enrollment and during treatment. Quality-of-care outcomes were obtained from a systematic review of the patient disease registry and compared with a previous study of patients with depressive symptoms in an MHIP. Descriptive analysis techniques were used to describe patients’ clinical characteristics.
Results
Primary care patients with bipolar disorder had high symptom severity on depression and anxiety measures: Patient Health Questionaire–9 (mean±SD score of 18.1±5.9 out of 27) and the seven-item Generalized Anxiety Disorder scale (15.7±4.7 out of 21). Psychosocial problems were common, with approximately 53% reporting concerns about housing, 15% reporting homelessness, and 22% reporting lack of a support person. Only 26% of patients were referred to specialty mental health treatment. Patients with bipolar disorder had a greater amount of contact with clinicians during treatment compared with patients with depressive symptoms from a prior study.
Conclusions
Primary care patients with bipolar disorder enrolled in MHIP had severe depression, symptoms of comorbid psychiatric illnesses, and multiple psychosocial problems. Patients with bipolar disorder received more intensive care compared with patients with depressive symptoms from a prior study. Referral to a community mental health center occurred infrequently even though most patients had persistent symptoms.
Given that many patients with common psychiatric illnesses present to primary care rather than specialty mental health settings, psychiatrists can support primary care physicians in the treatment of patients (1,2). For example, depression can be effectively treated in primary care with interventions such as collaborative care, where a psychiatrist supervises a care manager in treating a population of patients (2,3). Patients with depression and chronic general medical illnesses treated in primary care with psychiatrist-supervised collaborative care have shown improved short- and long-term depression outcomes (3), reduced disability from depression (4), improved quality of life (5), and lower total medical costs (6,7) compared with patients treated with usual care.
Partly because of this evidence, depression screening and treatment in primary care are gradually becoming standard clinical practice (8). However, primary care physicians, particularly those working in safety net settings, such as public clinics and federally qualified mental health centers, are often faced with treating patients who have serious mental illnesses (9). Unfortunately, little is known about the quality of mental health care or the course of severe and persistent mental illnesses, such as bipolar disorder, among primary care patients. In two systematic reviews, structured interviews have indicated that bipolar disorder occurs among as much as 4.3% of general primary care patients and up to 10% of primary care patients with a psychiatric complaint (10,11). Accurately recognizing bipolar disorder among patients in primary care systems is important because untreated bipolar disorder causes significant functional impairment and treatment differs from treatment of other psychiatric illnesses, such as major depression.
Patients with bipolar disorder may initially present to primary care for general health care. The prevalence of chronic general medical illnesses, such as diabetes and hypertension, is high among patients with bipolar disorder (12–14), and most patients generally obtain care for these conditions in primary care. In addition, prior studies have shown that 7.6% of veterans with bipolar disorder (15) and an estimated 10% to 38% (16) of nonveteran patients with bipolar disorder receive mental health care exclusively in primary care. Compared with patients treated in specialty mental health settings, patients with bipolar disorder treated exclusively in primary care settings were less likely to receive mood-stabilizing medications, suggesting the need to improve quality of recognition and treatment for bipolar disorder in primary care for these patients (15).
In one longitudinal study, patients with type I bipolar disorder experienced depressive symptoms three times as often as manic or hypomanic symptoms, and in another, patients with bipolar II disorder experienced depressive symptoms 39 times as often, thus indicating that patients with bipolar disorder are much more likely to present with depressive than manic or hypomanic symptoms (17,18). Patients with bipolar disorder, particularly bipolar II disorder, who are experiencing depressive symptoms often present initially to primary care (19). Psychiatrists might offer critical support and supervision for primary care physicians encountering patients with bipolar disorder.
In this study we aimed to describe the clinical characteristics of a large sample of primary care patients with bipolar disorder enrolled in an integrated care program. Increased understanding of the clinical characteristics of patients with bipolar disorder in primary care settings and identification of potential gaps in quality of care are the necessary first steps in the development of interventions to improve the quality of treatment for bipolar disorder in primary care.
Methods
Study setting and sample
The Washington State Mental Health Integration Program (MHIP) is a statewide program serving patients with general medical, mental health, and substance misuse needs (http://integratedcare-nw.org). At the time of this study, MHIP provided psychiatric services to patients in 141 federally qualified primary care clinics. Adults eligible for MHIP treatment include recipients of state assistance for unemployment and persons with temporary disability. Other recipient populations for these services include some low-income adults, low-income mothers and their children, uninsured older adults, and veterans and their family members enrolled in the participating community primary care centers. In Washington State, patients with Medicaid are eligible for care in community mental health centers and are therefore not included in the MHIP population.
MHIP is supported by the State of Washington and Public Health of King County and is administered by the Community Health Plan of Washington. The program uses collaborative care based on the IMPACT model (Improving Mood–Promoting Access to Collaborative Treatment) (2) to improve recognition and systematic treatment of patients with psychiatric disorders in primary care settings. Mental health treatment provided in primary care is referred to as level 1 care. Patients in MHIP also can be referred to one of 30 community mental health centers for a six-month course of specialty mental health care, termed level 2 care. MHIP uses a Web-based disease registry system that tracks visit dates, symptom ratings, medication use, and other clinical measures (http://integratedcare-nw.org). The disease registry facilitates systematic case reviews by consulting psychiatrists.
A total of 17,192 patients who were treated in MHIP between January 2008 and December 2011 were considered eligible for inclusion in this study. MHIP registries of all eligible patients were reviewed to obtain clinical information.
Bipolar disorder diagnosis
A bipolar disorder case was defined as the presence of a documented diagnosis of bipolar disorder by the consulting psychiatrist, primary care physician, or care manager and a positive result on the semistructured Composite International Diagnostic Interview, Version 3.0 (CIDI), defined as endorsing at least one of the stem questions and endorsing seven or more symptom questions (20,21). In MHIP, screening and case-identification measures, including the CIDI, are administered by the clinical care manager. Most care managers are mental health providers, social workers, or psychologists who are licensed or certified to provide clinical services in Washington State. Consulting psychiatrists review results of the care manager–administered measures, instruct care managers in appropriate use of each measure, and, if needed, request additional clinical information from the care managers through the use of standardized measures, clinical follow-up questions, or general clinical information sources, such as the medical record. Care managers receive initial and ongoing live and recorded Web-based training on the use of screening measures, brief psychotherapeutic interventions, and other clinical topics.
The CIDI is administered when clinicians are concerned about the possible presence of bipolar disorder. It was selected as the diagnostic evaluation for bipolar disorder in MHIP because in a national household survey, the CIDI was found to be highly concordant with the Structured Clinical Interview for DSM-IV, with a kappa of .94 for any bipolar spectrum diagnosis (defined as bipolar I disorder, bipolar II disorder, or subthreshold bipolar disorder symptoms), .88 for bipolar I disorder, and .88 for bipolar II disorder or subthreshold bipolar disorder symptoms (21). Of the 17,192 patients included in MHIP during the study period, 4,191 (24%) received the CIDI. Of those, 740 patients had CIDI results and a clinician diagnosis meeting case identification criteria.
Measurement, evaluation, and comparison
Clinical rating scales were administered to patients at enrollment in the program and throughout the treatment course in MHIP based on clinical status and recommendations by the consulting psychiatrist. Psychiatric history, treatment history, and psychosocial factors, such as employment history, living arrangements, and transportation access, were assessed with clinical questions. Depression was measured for most patients (97%, N=719) with the Patient Health Questionnaire–9 (PHQ-9), and a score of 10 or more was considered consistent with a high likelihood of meeting criteria for major depression, dysthymia, or both conditions at baseline (22). Anxiety symptoms were measured for most patients (95%, N=703) with the seven-item Generalized Anxiety Disorder scale (GAD-7); scores ≥10 indicate the highest sensitivity and specificity for meeting criteria for one of four anxiety disorders (posttraumatic stress disorder [PTSD], panic disorder, generalized anxiety disorder, or social phobia) (23). Substance use was measured with the Global Appraisal of Individual Needs–Short Screener (GAIN-SS) for most patients (93%, N=689), and a score ≥3 was considered representative of a high probability of current substance use problems (24). The PTSD Checklist (PCL) was used to measure symptoms of PTSD in a subsample (N=442). A score of 45 or more on the PCL indicates the greatest likelihood of meeting the diagnostic criteria for PTSD (25).
Quality-of-care outcomes were obtained from a review of the Web-based disease registry. We measured quality-of-care outcomes and included the five measures used in another study of the MHIP population (26). The five measures from that study were any follow-up contact within the first two and four weeks after initial evaluation, number of contacts in the first four weeks, total number of follow-up contacts during a treatment episode, and any psychiatric consultation during treatment (either a psychiatrist reviewing a patient’s case or an in-person consultation with the psychiatrist). Improvement on these five measures is associated with improved depression outcomes (26). Because the study sample included patients already receiving care in primary care settings, we were able to measure the percentage of patients referred from primary care to specialty mental health care, but we could not estimate the percentage of patients receiving care exclusively in primary care, as in a prior study (15).
All patients with baseline PHQ-9 scores ≥10 (88%, N=649) were used to estimate the percentage of patients experiencing depression improvement. Depression improvement was defined as achieving a PHQ-9 score of <10 or a reduction in PHQ-9 score by 50% or more from baseline during the course of treatment in MHIP. Course of treatment included time from initial assessment until level 1 treatment in MHIP or until the study ended. Sixty-five (9%) patients with a baseline but no follow-up PHQ-9 measurement were considered to show no improvement for depression. Our estimate adjusted for gender, age at enrollment, length of treatment during the study period, prior treatment history, current suicidal thoughts, and prior treatment for or current symptoms of anxiety, PTSD, substance misuse, chronic pain, and psychosis.
Data analysis
Descriptive techniques were used to describe the presenting characteristics of patients. Means and standard deviations were calculated in Stata, Version 12.0. All analyses were conducted on deidentified data collected for quality improvement purposes and were not considered research requiring individual patient consent by the University of Washington’s institutional review board.
Results
A total of 740 patients with bipolar disorder were identified. Baseline demographic and clinical characteristics of these patients are presented in Table 1. Patients with bipolar disorder commonly reported housing concerns and lack of dependable transportation. One-third of patients reported prior psychiatric treatment in inpatient facilities, and over half had prior psychiatric treatment in outpatient settings.
| Characteristic | N | % |
|---|---|---|
| Female | 326 | 44 |
| Psychosocial concernb | ||
| Lack of dependable transportation | 235 | 32 |
| Lack of support person | 163 | 22 |
| Concern about housing situation | 390 | 53 |
| Homelessness | 110 | 15 |
| Staying with someone or in shelter, car, motel, or other | 302 | 41 |
| Treatment historyb | ||
| Inpatient psychiatric hospitalization (≥1) | 246 | 33 |
| Outpatient psychiatric treatment | 421 | 57 |
| Substance abuse treatment | 351 | 47 |
| Disorder treated in past or showing current symptomsb | ||
| Bipolar disorder | 549 | 74 |
| Cognitive disorder | 239 | 32 |
| Psychosis | 254 | 34 |
| PTSD | 430 | 58 |
a
Mean±SD age was 38.9±10.6.
b
Self-reported by patients
Clinical characteristics
Results from standardized examinations are shown in Table 2. The mean±SD PHQ-9 score of 18.1±5.9 indicated moderately severe depression. Possible scores range from 0 to 27, with scores of 10–14, 15–19, and 20–27 indicating moderate, moderately severe, and severe depression, respectively. Fifty-eight percent of patients with bipolar disorder endorsed suicidal ideation on the PHQ-9 (score ≥1 on item 9 of the PHQ-9), and 28% of patients reported suicidal ideation on more than half of days or nearly every day of the prior two weeks (score ≥2 on item 9 of the PHQ-9). Two-thirds of patients (N=294 of the subsample of 442) with bipolar disorder who were administered the PCL had a PCL score >60, and the mean PCL score in the subsample was 63.4±13.2, with scores ≥45 indicating a high likelihood of meeting diagnostic criteria for PTSD.
| Measurea | N | % |
|---|---|---|
| PHQ-9 (N=719) | ||
| Mean±SD scoreb | 18.1±5.9 | |
| Score ≥10 | 649 | 90 |
| Item 9 scorec | ||
| 0 | 305 | 42 |
| 1 | 215 | 30 |
| 2 | 106 | 15 |
| 3 | 93 | 13 |
| GAD-7 (N=703) | ||
| Mean±SD scored | 15.7±4.7 | |
| Score ≥10 | 619 | 88 |
| GAIN-SS (N=689) | ||
| Mean±SD scoree | 1.4±1.9 | |
| 0 | 397 | 58 |
| 1–2 | 116 | 17 |
| ≥3 | 176 | 26 |
| PCL (N=442)f | ||
| <45 | 40 | 9 |
| 45–59 | 108 | 24 |
| ≥60 | 294 | 67 |
a
PHQ-9, Patient Health Questionnaire–9; GAD-7, seven-item Generalized Anxiety Disorder scale; GAIN-SS, Global Appraisal of Individual Needs–Short Screener; PCL, PTSD Checklist
b
Possible scores range from 0 to 27, with higher scores indicating greater depressive symptom severity.
c
Item 9 assesses suicidal ideation.
d
Possible scores range from 0 to 21, with higher scores indicating greater anxiety symptom severity.
e
Possible scores range from 0 to 5, with higher scores indicating greater likelihood of current substance use problems.
f
Possible scores range from 17 to 85, with higher scores indicating greater symptom severity.
Quality-of-care outcomes and comparison to previous research
Among 645 patients with bipolar disorder who were ultimately discharged from level 1 MHIP care, the mean duration of level 1 care was 30.1±22.7 weeks, with 36% of patients (N=232) receiving level 1 MHIP care for 33 weeks or more. Reasons for patient disenrollment from MHIP included new eligibility for Medicaid and Supplemental Security Income benefits (37%, N=238) and nonadherence with treatment (21%, N=132).
Twenty-six percent of patients with bipolar disorder were referred in 17.2±18.7 weeks to specialty mental health treatment at a collaborating community mental health center. The time from initial assessment to psychiatric consultation was 5.7±10.3 weeks among patients with bipolar disorder. Additional quality-of-care outcomes are shown in Table 3.
| Characteristic | N | % |
|---|---|---|
| Follow-up contacta | ||
| Within 2 weeks | 449 | 61 |
| Within 4 weeks | 559 | 76 |
| Within 8 weeks | 604 | 82 |
| Time from initial assessment to first follow-up contact (mean±SD weeks) | 3.9±8.4 | |
| Contacts in the first 4 weeks (mean±SD) | 1.4±1.2 | |
| Contacts in the first 8 weeks (mean±SD) | 2.4±1.9 | |
| Contacts during treatment (mean±SD) | 6.9±7.8 | |
| Case review by consulting psychiatrist | ||
| Within 2 weeks | 325 | 44 |
| Within 4 weeks | 411 | 56 |
| Within 8 weeks | 480 | 65 |
| Any psychiatric consultation during treatment | 575 | 78 |
| Time from initial assessment to first psychiatric case review (mean±SD weeks) | 5.7±10.3 | |
| Referral | ||
| Referred to community mental health treatment | ||
| center (level 2 referral) | 195 | 26 |
| Time from level 1 initial assessment to level 2 referral (mean±SD weeks) | 17.2±18.7 |
a
Follow-up contacts with care manager include in-clinic, by phone, in group, and meeting with care manager in other location.
Approximately one-third (33%±2% mean±SE) of patients with bipolar disorder with baseline PHQ-9 scores ≥10 experienced significant clinical improvement in depressive symptoms (PHQ-9 score <10 or a reduction in PHQ-9 score by 50% or more) during the time from initial MHIP assessment until level 1 treatment in MHIP or until the study ended.
We examined five quality-of-care measures associated with improved depression outcomes in prior research with MHIP (26) (Table 4). The prior study (N=7,941) consisted mainly of patients with depression, and the sample was 52% female, had a mean age of 41.3±11.9 years, and a mean baseline PHQ-9 score of 18.1±4.8 (26). A higher percentage of patients with bipolar disorder in our study had a clinical visit during the two-week (61% compared with 56% in the prior study) and four-week (76% versus 68%) periods after initial assessment, and patients with bipolar disorder had a greater number of contacts during treatment (6.9±7.8 versus 5.7±7.3). Furthermore, consultation with a psychiatrist occurred for a greater percentage of patients with bipolar disorder (78% versus 58%) than patients in the previously described MHIP population. In addition, we conducted a sensitivity analysis, leaving out 273 patients by applying our case definition of bipolar disorder to the prior study sample (26), and found similar results.
| Current study (N=740) | Prior study of depressed MHIP patients (N=7,941)a | |||
|---|---|---|---|---|
| Variable | N | % | Nb | % |
| Follow-up contact after initial assessment | ||||
| Within 2 weeks | 449 | 61 | 56 | |
| Within 4 weeks | 559 | 76 | 68 | |
| Contacts in first 4 weeks (mean±SD) | 1.4±1.2 | 1.3±1.3 | ||
| Total number of follow-up contacts during treatment (mean±SD) | 6.9±7.8 | 5.7±7.3 | ||
| Any psychiatric consultation during treatment | 575 | 78 | 58 | |
a
Unützer et al., 2012 (26)
b
No Ns were provided in the study for the variables shown.
Discussion
In this sample of primary care patients with bipolar disorder referred to a collaborative care mental health treatment program, most patients demonstrated moderate to severe depression, as well as comorbid psychiatric disorders, especially anxiety disorders and substance misuse. Social vulnerabilities, such as homelessness and lack of transportation, were also highly prevalent.
The National Comorbidity Survey Replication (NCS-R) (27) showed that approximately 75% of patients with bipolar disorder had a lifetime history of any anxiety disorder. Specifically, generalized anxiety disorder, social phobia, panic disorder, and PTSD occurred in 29.6%, 37.8%, 20.1% and 24.2% of the sample, respectively (27). Anxiety symptoms measured by the GAD-7 commonly occurred in our study, with 88% of patients having a score of ≥10. In addition over 90% of patients administered the PCL had a score of ≥45, indicating a high likelihood of meeting the diagnostic criteria for PTSD (25). Although this result was from a subsample, it supports our finding that many of the patients had moderate to severe comorbid anxiety symptoms, such as symptoms that can occur with PTSD.
Previous studies have demonstrated that compared with persons without an anxiety disorder, patients with bipolar disorder and comorbid anxiety disorders are less likely to be euthymic, have a greater burden of depression symptoms, and may be less responsive to brief, but not more intensive, psychotherapeutic treatments (28,29). Enhancing the psychotherapeutic treatment of bipolar disorder and comorbid anxiety in primary care may be one way to reduce depressive and anxiety symptoms of patients with bipolar disorder (29).
In the NCS-R, 42% of patients with bipolar disorder had ever had a substance use disorder (27); a similar prevalence was found in a clinical sample (30). Almost one-half of the patients in our sample reported prior treatment for a substance use disorder or current substance use. Also, one-quarter of the patients with bipolar disorder in our study demonstrated a high likelihood of current substance use problems, as indicated by a GAIN-SS score of ≥3. A score ≥1 on the GAIN-SS captures a greater number of individuals with current substance misuse who would likely benefit from a substance use intervention but have not reached the level of severity of dependence (24). Over 40% of our sample had a GAIN-SS score of ≥1. Because substance use in bipolar disorder has been associated with greater psychosocial impairment (31), improving functional outcomes of primary care patients with bipolar disorder likely requires assessment and treatment of co-occurring substance use problems.
Suicidal ideation was experienced by 58% of patients with bipolar disorder, which is higher than the occurrence of suicidal ideation (45%) in a previous report on the overall MHIP population (32). In addition, a higher percentage of patients with bipolar disorder (28%) reported experiencing suicidal ideation more than half of days or nearly every day compared with the sample of patients (22%) from the previous MHIP report (32).
Psychosocial impairments were common in our sample of patients with bipolar disorder, most notably, homelessness. Fifteen percent of patients with bipolar disorder reported being homeless, and 41% reported staying with others or in a shelter. This is consistent with research findings from a large public mental health system showing homelessness of 17% of patients with bipolar disorder who received care in the San Diego County public mental health system (33). Our sample, which had a similar prevalence of homelessness, came from primary care settings, suggesting that homelessness is common among patients with bipolar disorder seen in primary care as well as mental health care safety net settings.
We also found that MHIP patients with bipolar disorder experienced more intensive and perhaps higher-quality treatment compared with MHIP patients with depression from a previous study of 7,941 patients (26). The high occurrence of comorbid psychiatric illnesses, suicidal ideation, and substance misuse among the patients with bipolar disorder likely led to increased clinical contact during treatment. A higher number of clinical contacts, such as follow-up within two- and four-week periods from initial assessment and consultation with a psychiatrist, has been associated with better depression outcomes in MHIP (26).
Although two-thirds of the patients with bipolar disorder had persistent depressive symptoms, only 26% of patients with bipolar disorder were referred to a community mental health center. Reasons for this low referral rate may include barriers to referral, such as limited community mental health resources, and patients’ preferring to receive treatment in primary care.
Limitations of the study include that our sample monitored only patients who were referred to psychiatric treatment in a collaborative care model. Our sample may have been biased toward having greater illness severity, because disability or unemployment occurs among most patients referred to MHIP. Third, some patients with bipolar disorder may not have been included in the study sample. In addition, it is possible that some patients in the bipolar sample did not have bipolar disorder, because the positive predictive value of the CIDI in primary care ranges from 59% to 73% (20). We aimed to minimize the number of false positives by also requiring a documented clinician diagnosis of bipolar disorder. Finally, because we considered all patients with only a baseline PHQ-9 score as having no depression improvement, our estimate of depression improvement may have been conservative.
Conclusions
Primary care patients with bipolar disorder experienced persistent depressive and anxiety symptoms despite higher-intensity collaborative care treatment, but they were infrequently referred to a community mental health center. Successful treatment of bipolar disorder in primary care may require additional clinical interventions aimed at either further improving the care delivered to patients in primary care or through more effective referrals to community mental health centers.
Acknowledgments and disclosures
This work was supported by grant T32-MH020021-16 from the National Institute of Mental Health. The authors thank Community Health Plan of Washington, Public Health Seattle, and King County for sponsorship and funding of the MHIP and for data on quality of care and clinical outcomes collected in the context of ongoing quality improvement.
The authors report no competing interests.
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Cover: Deep Cove Lobster Man, by N. C. Wyeth, ca. 1938. Oil on gessoed board (renaissance panel). Accession number 1939.16. Courtesy of the Pennsylvania Academy of Fine Arts, Philadelphia, Joseph E. Temple Fund.
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Published in print: August 2014
Published online: 15 October 2014
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