Pathophysiology & Risk Factors

Bipolar I disorder is a chronic, lifelong mood disorder that cycles between manic and depressive phases. A manic episode is a distinct period (>=7 days, or any duration if hospitalization is required) of abnormally elevated, expansive, or irritable mood plus increased goal-directed energy. Clients spend the most time in — and carry the greatest illness burden from — the depressive phase, which lasts longer and carries higher suicide risk than mania. Treatment differs fundamentally from unipolar depression: antidepressant monotherapy can trigger a manic switch or rapid cycling, so mood stabilizers form the foundation and maintenance therapy is lifelong.

Signs & Symptoms

Which phase is this? Manic vs depressive discriminator

Manic phaseDepressive phase

Mood / energyElevated/irritable, increased goal-directed energyLow mood, anhedonia, fatigue

SleepDecreased need, feels rested on 2-3 hrsHypersomnia or insomnia

Speech / thoughtPressured speech, flight of ideasSlowed speech, poverty of thought

Risk behaviorsSpending sprees, sexual indiscretionSuicidal ideation

Priority nursing focusSafety, nutrition/hydration, sleep, limitsSuicide risk, adherence, hopelessness

Manic phase

Mood / energy: Elevated/irritable, increased goal-directed energy
Sleep: Decreased need, feels rested on 2-3 hrs
Speech / thought: Pressured speech, flight of ideas
Risk behaviors: Spending sprees, sexual indiscretion
Priority nursing focus: Safety, nutrition/hydration, sleep, limits

Depressive phase

Mood / energy: Low mood, anhedonia, fatigue
Sleep: Hypersomnia or insomnia
Speech / thought: Slowed speech, poverty of thought
Risk behaviors: Suicidal ideation
Priority nursing focus: Suicide risk, adherence, hopelessness

Diagnostics & Labs

1 · Acute mania target (1.0-1.5)

Toxicity threshold

Subtherapeutic

Maintenance range

Above maintenance

Toxic

0.6

1.2

1.5

mEq/L

Interventions & Priorities

ensure safety

impulsivity, aggression, exhaustion

reduce environmental stimuli

dim lights, minimize noise, limit groups

offer portable high-calorie foods and fluids

client too agitated to sit for meals; prevents dehydration

structure designated rest periods

sleep deprivation perpetuates mania

set firm consistent limits

nonpunitive boundaries on unsafe behavior

use brief directive communication

short attention span; do not argue delusions

assess suicide risk in depressive phase

Treatments & Medications

lithium

mood stabilizer; bipolar depression and lifelong relapse prevention

lamotrigine

prevents depressive episodes; slow titration; NOT for acute mania

quetiapine

atypical antipsychotic; FDA-approved for bipolar depression

olanzapine

atypical antipsychotic; metabolic/weight-gain side effects

mood stabilizer foundation Hallmark

any antidepressant must be paired with a mood stabilizer

Patient Teaching

continue medication when feeling well

discontinuation during stable periods is the top relapse cause

maintenance therapy is lifelong

maintain consistent sleep-wake schedule

stabilizes circadian rhythm

maintain adequate fluid intake

dehydration concentrates lithium

do not start a low-sodium diet without provider

sodium depletion raises lithium levels

avoid alcohol

destabilizes mood and disrupts sleep

track individualized early warning signs

sleep, activity, spending changes unique to client

manage weight on antipsychotics with diet and exercise

Report Nowescalate immediately

lithium toxicity signs

nausea, vomiting, diarrhea, worsening hand tremor

dehydration on lithium

concentrates serum lithium toward toxicity

suicidal ideation

highest in the depressive phase

exhaustion or dehydration in acute mania

too distracted to eat, drink, or rest

lamotrigine rash

may signal Stevens-Johnson syndrome

Clinical Pearl

DIG FAST spots the mania; "no antidepressant flies solo" keeps the guardrails on — and on lithium, anything that drops sodium or water (vomiting, sweating, a low-salt diet) drives the level toward toxicity.