Mania: Differential diagnosis
Bipolar spectrum disorders
Bipolar spectrum disorders are categorized in the DSM-IV into four types:
- Bipolar I disorder: Features at least one manic or mixed episode.
- Bipolar II disorder: Involves hypomania and depression, possibly the most common bipolar presentation in primary care. Affected individuals often use health services while depressed and do not respond sufficiently to conventional antidepressants, which may be mistaken as treatment-resistant depression.
- Cyclothymic disorder: Continuous biphasic mood instability for two years or more in adults, but never severe enough to meet criteria for a major depressive episode or mania.
- Unspecified bipolar and related disorder
DSM 5 has an additional type: Other specified bipolar and related disorder. See Highlights of Changes from DSM-IV to DSM-5.
The psychiatric disturbance should not be fully accounted for by the effects of a general medical condition or substance.
Antidepressants and hypomanic symptoms
A common clinical scenario in primary care is mania or hypomania in a patient receiving antidepressant monotherapy with no prior manic or mixed episodes. Although the DSM would suggest that this patient is "antidepressant-induced," evidence indicates that antidepressants do not cause mania but exacerbate pre-existing hypomanic symptoms or unmask hypomanic symptoms in a vulnerable individual.
Other considerations in differential diagnosis
Other considerations in the differential diagnosis of bipolar disorder include major depressive episode with prominent agitation/anxiety, premenstrual dysphoric disorder, seasonal affective disorder and personality disorders.
Borderline personality disorder
Borderline personality disorder (BPD) is not a diagnosis of exclusion for bipolar disorder. Many patients have both conditions. The defining features of BPD are an enduring and pervasive pattern of interpersonal relations that is chaotic and tempestuous, with complaints of emptiness and "attachment difficulties." Individuals with BPD often have experienced trauma, such as childhood adversity.
Approximately 50 to 95 per cent of people with bipolar disorder have psychotic features. They are more likely to experience psychotic features during manic than depressive episodes. Mood-congruent delusions such as grandiosity and mood-incongruent delusions such as paranoia are the most common psychotic features. Psychosis presenting as a form of thought disorder (e.g., tangentiality) is also common.
Although hallucinations and "vivid" perceptions also often occur, hallucinations underscore the need to rule out "organic" causes and substance use. In any patient with psychotic features, the possibility of a primary psychotic disorder such as schizophrenia should to be considered.
Bipolar disorder: Assessment and management (NICE guideline CG185, 2014)