Major depressive disorder (MDD) and bipolar spectrum disorders are associated with some symptoms of—and fully defined—posttraumatic stress disorder (PTSD). Many traumatic experiences can lead to this comorbidity, the most common being exposure to or witnessing combat for men and rape and sexual molestation for women.1
Trauma has major prognostic and treatment implications for affectively ill patients, including those whose symptoms do not meet PTSD’s full diagnostic criteria. This article aims to help clinicians by:
- presenting evidence characterizing the overlap between affective disorders and PTSD
- reviewing evidence that the bipolar spectrum may be broader than generally thought, an insight that affects PTSD treatment
- making a case for routine PTSD screening for all patients with affective illnesses
- recommending PTSD treatments tailored to the patient’s comorbid affective disorder.
Overlap of trauma and affective illness
PTSD is remarkably comorbid with mood disorders. Americans with MDD and bipolar disorder (BPD) are 7 and 9.4 times, respectively, more likely to meet criteria for PTSD than persons in the general population, according to odds ratios Kessler et al2 calculated from the National Comorbidity Survey database.
I have never seen a patient with PTSD who did not also meet criteria for an affective disorder. The concurrence of PTSD and MDD is not the product of overlapping diagnostic criteria. Rather, evidence indicates these are distinct diagnostic entities.3 A review of diagnostic criteria for PTSD and hypomania/mania leads to the same conclusion.
Bipolar spectrum disorders
DSM-IV-TR assumes that mood disorders fall neatly into boxes. Other data (Table 1)4–8 indicate that these disorders fall along a continuum or—more conservatively—that the scope of bipolarity is much wider than DSM-IV-TR recognizes. This is a controversial topic, and the individual clinician’s position could impact how one manages PTSD patients.
Table 1
Evidence of bipolar spectrum features in major depressive episodes
Study | Design | Conclusion |
---|---|---|
Akiskal and Mallya, 19874 | 200 community mental health clinic patients diagnosed as having MDD | 50% could be classified as having a bipolar disorder |
Benazzi, 19975 | 203 consecutively presenting patients with depression | 45% met criteria for bipolar II disorder |
Akiskal and Benazzi, 20056 | 563 consecutive patients presenting with a DSM-IV-diagnosed MDE | 58% showed features of bipolar II disorder |
Akiskal et al, 20067 | 493 patients in a French national study presenting with MDE | 65% were determined to fall along the ‘bipolar spectrum’ |
Rabakowski et al, 20058 | 880 Polish outpatients presenting with MDE | 40% met criteria for bipolar disorder |
MDD: major depressive disorder; MDE: major depressive episode |
In this article, I include bipolar I disorder, bipolar II disorder, and mixed depression within the “bipolar spectrum disorders.” If one accepts this—and I do—it follows that 50% to 70% of all major depressive episodes (MDEs) are bipolar in nature.4–9 Depending on your practice setting, you may see a higher or lower base rate of bipolar spectrum disorders.
Mixed depression is not recognized in DSM-IV-TR, and the purpose of this article is not to defend its inclusion as a bipolar spectrum phenomenon. A proposed definition of mixed depression9 requires the presence of an MDE contaminated by ≥3 features of hypomania or mania, without euphoria or inflated self-esteem/grandiosity (Table 2).10
Some experts believe episodes of hypomania and mania frequently occur in the illness course of persons with mixed depression; indeed, mixed depression is a predictor of a bipolar course. It is observed in outpatient9 and inpatient settings.11 Common forms of mixed depression feature combinations of irritability, psychomotor agitation (mild to severe), increased talkativeness (which may fall short of frank pressured speech), racing or “crowded” thoughts (or “mental overactivity”), and distractibility. Other than increased self-esteem/grandiosity, any symptoms within DSM-IV-TR criterion B for a hypomanic or manic episode may be seen in mixed depression. Psychosis is an exclusion criterion for mixed depression.
Mixed depression responds poorly to antidepressant monotherapy. Validation studies suggest that mixed depression is a bipolar variant, as determined by its capacity to predict a bipolar course and its association with a family history of bipolar disorder and age of onset.9
Table 2
Diagnostic characteristics of a hypomanic episode, DSM-IV-TR criteria A and B
A. A distinct period of persistently elevated, expansive, or irritable mood, lasting throughout at least 4 days, that is clearly different from the usual nondepressed mood. |
B. During the period of mood disturbance, 3 or more of the following symptoms have persisted (4 if the mood is only irritable) and have been present to a significant degree: 1) inflated self-esteem or grandiosity 2) decreased need for sleep (eg, feels rested after only 3 hours of sleep) 3) more talkative than usual or pressure to keep talking 4) flight of ideas or subjective experience that thoughts are racing 5) distractibility (ie, attention too easily drawn to unimportant or irrelevant external stimuli) 6) increase in goal-directed activity (either socially, at work or school, or sexually) or psychomotor agitation 7) excessive involvement in pleasurable activities that have a high potential for painful consequences (eg, the person engages in unrestrained buying sprees, sexual indiscretions, or foolish business investments). |
Source: Diagnostic and statistical manual of mental disorders, 4th ed, text rev. Washington, DC: American Psychiatric Association; 2000 |