Major depressive episode and bipolar disorders: same DSM-5 diagnostic criteria, but very different disorders.
Although the DSM-5 diagnostic criteria for a major depressive episode are the same for unipolar and bipolar disorders, these episodes differ in their natural past history (ie, patients with bipolar disorders will have discrete episodes of hypomanias or manias), age of onset, suicide risk, associated comorbidities, and biological correlates. And, most importantly, they differ dramatically in the medications that are effective. Thus, it is critical to diagnose them correctly.
To do so, you must take a good history for hypomania or mania, because this is where diagnostic error commonly occurs. Start by informing the patient how important it is to have the correct diagnosis for effective treatment and that being wrong about the diagnosis can lead to the wrong treatment—which is at best ineffective and at worst very harmful (eg, antidepressants can cause a malignant transformation in bipolar disorder to a rapid cycling and treatment-resistant condition).1-3 This warning to the patient hopefully overrides their potential reluctance to disclose manic symptoms because of the stigma of the diagnosis, their enjoyment of the experience, or their belief that it represents their normal mood and energy that they would like to return to and maintain.
Painting a Picture of Mania
Start by describing an episode of mania or hypomania. Patients often wake up feeling, for no particular reason, unusually energetic, with thoughts racing about millions of things they want to get done. They want to start new projects, clean and organize the house, add to their possessions, contact neglected friends. They set out to do those projects and then they go-go-go day and night, feeling a lessened need for sleep or maybe skipping sleep completely for a night or so. They almost invariably spend money to fund the ventures or add to hobbies, clothes, or possessions. Often, they already have plenty of what they are buying and they later recognize that the purchases were unnecessary. They discount the importance of other bills, thinking they will figure out how to pay those at some future date, believing the new purchases to be more important.
Explain that during mania their speech is accelerated and increased in quantity and volume. This tends to be noticed by others, who will advise them to “slow down” so they can be understood. Friends and family may see their plans as impractical, unrealistic, or risky, but patients in the grip of mania will ignore this feedback and often lash out and become irritable and defensive. At work, if there are disagreements with the boss, there can be loud arguments, and the person with mania can impulsively quit or get fired, which they later regret.
Their disinhibited speech can also include embarrassing self-disclosures, undiplomatic criticisms of others, or inappropriate sexualized content. Their property can be littered with tools and supplies for projects that were never finished, because when the manic episode ends, they lose all interest in the activity. Parts of their house may be partly demolished in preparation for the project and then stay that way for years, because when the next manic episode begins, they usually start an entirely different project. Make it clear to the patient that the episodes you are talking about last at least a few days and nights, often more.
At this point, stop and see if the patient recognizes these behavioral patterns. If it is unclear, bring up some additional symptoms: social overactivity, hazardous driving patterns, uncharacteristically starting conversations with strangers, and commonly sexual preoccupations and overactivity (this is a cause, although not the only one, of infidelity in established relationships, often resulting in the end of the primary relationship). It is often best to leave inquiries about sexual indiscretions to a later time due to possible embarrassment for them, but by the time you bring it up, you might get a very emphatic response of “absolutely!” about this symptom.
Diagnosis and Treatment
If the patient reports that these events do occur, get details about how long they last, how frequently the behaviors occur, and whether they cause significant impairment in social or work relationships, have legal consequences, or result in financial hardship. This will determine whether the patient meets the criteria for bipolar I or II, and rapid versus nonrapid cycling.
If the patient does not report criteria-meeting manic episodes, it is possible that they have prebipolar depression and could have a hypomanic or manic episode in the future.4 Initial manias have occurred in elderly patients after decades of depressions. A number of factors may predict when a unipolar major depressive disorder diagnosis could change to a bipolar disorder (Table).4 If enough predictors are present, including failure on previous antidepressant trials, consider treating the depression as a bipolar depression and taper off any antidepressants as you do so.
Dr Osser is associate professor of psychiatry at Harvard Medical School and co-director, US Department of Veterans Affairs National Bipolar Disorders Telehealth Program. The author reports no conflicts of interest concerning the subject matter of this article.
1. Post RM. Preventing the malignant transformation of bipolar disorder. JAMA. 2018;319(12):1197-1198.
2. El-Mallakh RS, Ghaemi SN, Sagduyu K, et al; STEP-BD Investigators. Antidepressant-associated chronic irritable dysphoria (ACID) in STEP-BD patients. J Affect Disord. 2008;111(2-3):372-377.
3. El-Mallakh RS, Vöhringer PA, Ostacher MM, et al. Antidepressants worsen rapid-cycling course in bipolar depression: a STEP-BD randomized clinical trial. J Affect Disord. 2015;184:318-321.
4. Faedda GL, Baldessarini RJ, Marangoni C, et al. An International Society of Bipolar Disorders task force report: precursors and prodromes of bipolar disorder. Bipolar Disord. 2019;21(8):720-740. ❒