Bipolar Disorders

Core Concepts

Episodes, not personality

The key idea is that bipolar disorders are episodic: symptoms come and go in time-limited states that are different from the person's usual self. This is why a nurse who knows the patient well is valuable — a change from baseline is the first clue. Mania is a distinct period of abnormally elevated, expansive, or irritable mood plus persistently increased activity or energy, lasting at least one week (or any duration if hospitalization is required), causing marked impairment or, in some cases, psychotic features. Hypomania is a shorter (at least four days) and milder version of the same picture: a clear change the person or others notice, but without marked impairment or psychosis. These descriptions are for learning; only qualified clinicians make the diagnosis.

The bipolar spectrum: I, II, and cyclothymic disorder

• Bipolar I — at least one full manic episode. Depressive episodes are common but not required for the diagnosis.
• Bipolar II — hypomanic episodes plus at least one major depressive episode, with no full manic episode. (If a full manic episode ever occurs, the diagnosis is no longer bipolar II.)
• Cyclothymic disorder — chronic hypomanic and depressive symptoms for at least two years (one year in children and adolescents), never meeting full criteria for a manic or major depressive episode.

A practical consequence: many people with bipolar II spend far more time depressed than hypomanic, so they can be mistaken for having unipolar depression. Asking about past episodes of unusually high energy, little need for sleep, or rapid talking is part of a careful history.

Mixed features and rapid cycling

Two course patterns deserve special attention. Mixed features means manic and depressive symptoms occur together in the same episode — for example, a person with a depressed mood who is also agitated, sleepless, and racing with thoughts. Mixed states are considered high-risk periods, in part because agitation and hopelessness combine. Rapid cycling means four or more mood episodes within twelve months; it is more common in women and is associated with a more difficult course. Both are course descriptors, not separate diagnoses.

What is known about causes: history and biology

Two strands of evidence shape current understanding. Family and twin studies show that bipolar disorders run in families and that identical twins are more likely to share the condition than fraternal twins, pointing to a strong genetic contribution. Methodological note: twin studies rest on assumptions about shared environments, and their results describe populations, not individuals — they do not predict any one person's outcome. Brain research implicates dysregulation in mood-regulating circuits and neurotransmitter systems, but no single biological explanation exists yet; the cause is understood as a combination of genetic vulnerability and life circumstances.

The lithium story is a landmark worth knowing. In 1949 the Australian psychiatrist John Cade reported that lithium salts calmed manic behavior — first observed in guinea pigs, then in patients. Judged by modern standards the studies were small and uncontrolled, yet the finding launched the modern era of mood-stabilizing treatment. Lithium remains a mainstay of treatment but has a narrow therapeutic range, so it requires blood-level monitoring and provider management. The nurse's role is education and monitoring: explaining why blood draws matter, supporting adherence, and teaching the person to report concerning side effects — never dosing or adjusting medication.

Nursing care across the poles

• During mania — safety first. The person may be impulsive, grandiose, and sleeping almost nothing. A low-stimulation environment, structured routine, and regular meals and fluids are standard supports because people in mania often forget to eat and sleep. Redirect high energy into safe, contained activity; set limits calmly and respectfully; and escalate rising agitation promptly to the provider per facility policy — including any institutional protocol for crisis response.
• During depression — suicide risk is the priority. The nurse assesses for expressed hopelessness or thoughts of self-harm and reports immediately to the provider and treatment team, following facility policy for safety checks and support. (See the Self-Harm and Suicide topic.)
• Across phases — medication adherence teaching, sleep regularity (sleep loss can trigger episodes), education about alcohol and stimulant use, family education, and linkage to follow-up care.

Scope note: assessment, monitoring, safety, education, and reporting are core nursing work; diagnosis, medication selection, dosing, and treatment decisions are provider responsibilities, and every facility has its own policies for escalation, safety checks, and crisis response.

Common Confusions