Bipolar Disorder: Recognizing and Treating in Primary Care

Primary care clinicians are often the first point of contact for persons with bipolar disorder. Unfortunately, delays in diagnosis are common, as many of these patients are misdiagnosed with unipolar depression on initial presentation. Since an early and accurate diagnosis may reduce the burden of bipolar disorder and improve outcomes, clinicians should be able to recognize its symptoms and initiate treatment of this deceptive disorder.

Bipolar disorder is a chronic mental illness characterized by fluctuations in mood and energy that manifests as recurrent episodes of manic or depressive symptoms. It is estimated that between 10% and 38% of patients with bipolar disorder receive all their mental health care in a primary care setting.¹ Although patients with bipolar disorder often initially pre­sent to their primary care provider, they frequently go undiagnosed because of the complexity of the disorder’s symptomatology and a low index of suspicion among primary care providers.² Comorbid medical conditions and psychiatric issues can also lead to misdiagnoses.

Because primary care providers are often the first point of contact for patients with bipolar disorder, they are well positioned to recognize bipolar symptoms early in the course of the illness. The pure subtypes of bipolar disorder include bipolar I and bipolar II. Clinicians who work in a primary care or emergency department setting should be able to recognize and initiate treatment for these two subtypes while the patient is waiting for a psychiatric evaluation. Accurate early diagnosis of this disabling disorder can reduce morbidity and improve outcomes by allowing for appropriate referral, pharmacotherapy, and psychotherapy.

DEFINITION

According to the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5), bipolar disorder is a mood disorder defined by episodes of mania, hypomania, and major depression.³ Patients with bipolar I disorder experience manic episodes and almost always experience major depressive and hypomanic episodes. Bipolar II disorder is marked by at least one hypomanic episode, at least one major depressive episode (MDE), and the absence of manic episodes.³ A manic episode is at least one week of abnormally and continually elevated, expansive, or irritable mood and increased activity or energy accompanied by at least three of the following symptoms (or four if mood is only irritable): inflated self-esteem, decreased need for sleep, increased talkativeness, flight of ideas or racing thoughts, marked distractibility, increased goal-directed activity or agitation, and excessive involvement in dangerous or high-risk activities (eg, reckless spending or increased sexuality). To be considered a manic episode, the mood disturbance must cause marked impairment in social or occupational functioning, result in hospitalization, or involve psychotic features, and the symptoms cannot be attributable to the effects of drugs or medications or another medical condition.³

In a hypomanic episode, the period of elevated or irritable mood lasts for a shorter duration (at least four days); is associated with a clear, uncharacteristic change in functioning; and is observable by others but does not cause marked impairment, need for hospitalization, or psychosis. MDE is defined by the presence of at least five of nine symptoms for a minimum duration of two weeks and a change from previous functioning: depressed mood, markedly decreased interest or pleasure in activities, significant change in weight or appetite, insomnia or hypersomnia, psychomotor agitation or retardation, fatigue or loss of energy, feelings of worthlessness or excessive guilt, decreased ability to think or concentrate or indecisiveness, and recurrent thoughts of death or suicidality (at least one symptom must be depressed mood or loss of interest or pleasure).³

EPIDEMIOLOGY

Bipolar disorder affects men and women equally. It can occur at any age but is seen most commonly in persons younger than 25.⁴ The mean age at the first manic/hypomanic or major depressive episode was determined to be 18.2 in bipolar I and 20.3 in bipolar II.⁵ The lifetime prevalence of bipolar disorder in the United States is around 4%, with one study finding prevalence estimates of 1.0% for bipolar I disorder and 1.1% for bipolar II disorder.⁵

Bipolar disorder is common among primary care patients with depression. Two studies that explored the risk for bipolar disorder among depressed outpatients in primary care settings found that between 20% and 30% of these patients screened positive for bipolar disorder on the Mood Disorders Questionnaire (MDQ), indicating that a more thorough evaluation for bipolar disorder was needed.^6,7 A systematic review of the literature found similar rates of positive results on the MDQ screening measure among primary care patients with depression, a trauma exposure, medically unexplained symptoms, or a psychiatric complaint; bipolar disorder was diagnosed with a structured clinical interview in 3% to 9% of these patients.⁸ Children of parents with bipolar disorder have a 4% to 15% risk for also being affected.⁴