On average
people with Bipolar I Disorder spend three times more in a depressive episode
than in a manic or hypomanic state; those with Bipolar II Disorder suffer 40
times more in a depressive episode than in a manic or hypomanic state.
According to DSM-5 a bipolar depressive episode and a unipolar depressive
episode have the same diagnostic criteria marked by five of the following nine
symptoms for two weeks:
- Depressed mood
- Loss
of pleasure
- Weight
or appetite change
- Change
in sleep
- Psychomotor
agitation or retardation
- Fatigue
- Feelings of worthlessness
or guilt
- Indecisiveness or trouble
concentrating
- Suicidal
ideation
Bipolar I
patients have had at least one manic episode lasting at least one week during
which time the person feels euphoric and overly optimistic or is
extremely irritable marked by three of the following symptoms:
- Unrealistic,
grandiose beliefs about one’s abilities or powers
- Rapid
speech that makes it difficult for others to keep up
- Acting recklessly without
thinking about the consequences
- Racing thoughts, jumping
quickly from one idea to the next
- Distractibility
marked by poor concentration and attention
- Impulsiveness,
poor judgment, agitation or excessive goal pursuit
- Sleeping
very little but without loss of energy
Bipolar II
patients have had at least one hypomanic episode that differs from mania by
intensity and duration. A hypomanic episode is only required to persist for
four days instead of seven. Those in a hypomanic state can make bad decisions
that harm relationships, careers, and reputations, but they are able to perform
without losing touch with reality.
Three
medications have been approved by the FDA for the treatment of acute bipolar
depressive episodes:
- Seroquel
(quetiapine)
- Symbyax
(a combination of fluoxetine and olanzapine)
- Latuda
(lurasidone)
Seroquel can
contribute to significant weight gain and metabolic syndrome as can Symbyax.
Both Latuda and Symbyax are expensive.
Lithium listed
as first-line treatment for acute bipolar depression in the APA practice
guidelines also has the following advantages:
- FDA approval for acute
manic episodes
- FDA approval for
maintenance treatment for those bipolar patients with a history of mania.
- Frequently used to
augment antidepressants in treatment resistant major depression.
- Works rapidly (1-3 weeks)
- Is inexpensive
- Substantially decreases
suicide risk
- May be useful for
episodic rage, anger or violence unassociated with bipolar illness
- May be useful for
self-destructive behavior found in personality disorders
Lithium is
underutilized. Because lithium is a generic medication pharmaceutical companies
have little incentive to seek FDA approval for Bipolar II depression.
In most cases the
benefits of lithium supersede the risks with the following precautions:
- Regular blood levels are
necessary because toxic levels characterized by nausea, vomiting,
diarrhea, slurred speech, gross tremor and staggering occur close to
therapeutic effects. With proper dosing and monitoring these side effects
rarely occur.
- Should be avoided in
patients with severe kidney disease, dehydration or sodium depletion
- Category D in pregnancy
with positive evidence of risk to human fetus
The initial dose
can be begun at 300 mg 2-3 times daily. Alternatively the cautious clinician
can prescribe 300 mg lithium at night. After one week the dose can be increased
to 600 mg. Following another week the dose can be increased to 900 mg. Baseline
labs and a lithium level can be drawn within a week of starting lithium.
Gradually titration slows the time to response.