Should lithium be continued in a patient who still has gambling problems and whose bipolar diagnosis is uncertain?

Discontinue Lithium and Reassess the Diagnosis

If lithium has shown no effect on gambling behavior and the bipolar diagnosis is uncertain, lithium should be discontinued. The patient's gambling disorder appears to be the primary clinical problem requiring targeted treatment, not a manifestation of bipolar disorder.

Clinical Reasoning

Lithium's Specific Indication

Lithium is FDA-approved exclusively for bipolar disorder—specifically for treating manic episodes and maintenance therapy to reduce frequency and intensity of manic episodes 1. The drug has no indication for gambling disorder as a primary condition. If the bipolar diagnosis is questionable and lithium has demonstrated no therapeutic benefit, continuing it exposes the patient to unnecessary risks without clinical justification.

Evidence for Lithium in Gambling Disorder

The only scenario where lithium shows efficacy for gambling is when gambling disorder co-occurs with confirmed bipolar spectrum disorder. A 2005 randomized controlled trial found that sustained-release lithium significantly reduced gambling severity in pathological gamblers with bipolar spectrum disorders, with 83% of completers responding versus 29% on placebo 2. Critically, improvement in gambling correlated directly with improvement in mania ratings 2. This means lithium treats the underlying bipolar disorder, which secondarily improves gambling behavior—it does not treat gambling disorder itself.

A 2014 case report similarly demonstrated lithium's effectiveness only in gambling patients with comorbid bipolar spectrum conditions and euphoric temperament 3.

The Diagnostic Imperative

Without a confirmed bipolar diagnosis, lithium has no role. The patient's lack of response suggests either:

1. No underlying bipolar disorder exists (most likely given your uncertainty)
2. The gambling is not secondary to mood instability
3. Lithium is simply ineffective for this individual's bipolar disorder

What Should Happen Next

Immediate steps:

• Discontinue lithium to avoid unnecessary side effects (tremor, polyuria, weight gain, renal effects) 4
• Conduct formal diagnostic reassessment for bipolar disorder using DSM-5 criteria
• Screen for other psychiatric comorbidities common in gambling disorder: depression (30%), anxiety disorders, ADHD, substance use disorders (56% nicotine, 18% alcohol abuse) 5

If bipolar disorder is ruled out:

• Refer for evidence-based gambling disorder treatment: cognitive behavioral therapy and psychoeducation 5
• Consider pharmacotherapy targeting gambling disorder specifically (not lithium)
• Note that gambling disorder is now classified as an addiction disorder, not an impulse control disorder

If bipolar disorder is confirmed:

• Lithium remains the gold standard for bipolar maintenance treatment 6
• Ensure adequate therapeutic levels (requires monitoring)
• Recognize that gambling may improve only if it's secondary to mood episodes

Critical Pitfall to Avoid

Do not continue lithium "just in case" or based on vague diagnostic uncertainty. Lithium requires regular laboratory monitoring, has significant side effects, and carries risks including renal impairment and thyroid dysfunction 1. The WHO guidelines explicitly state lithium should only be initiated "in those settings where personnel and facilities for close clinical and laboratory monitoring are available" 6. Without a clear indication, this burden is unjustified.

The "Dopamine and Serotonin" Hypothesis

Your mention of "lack of dopamine and serotonin" suggests consideration of depression or other neurotransmitter-based disorders. This further supports discontinuing lithium, as it is not a first-line treatment for unipolar depression or primary neurotransmitter deficiency states. If depression is suspected, SSRIs would be more appropriate—but only after establishing the correct primary diagnosis.

Bottom line: Stop the lithium, clarify the diagnosis, and treat what's actually present.