Most side effects of mood stabilizers are transient, meaning they get better or go away after a few weeks, but some persist. They are generally reversible after the medication is discontinued. Common side effects include:

• Gastrointestinal complaints (e.g., nausea, vomiting, diarrhea). A very common side effect that generally improves if the medication is taken with meals.
  
  
• Fine tremor. Shakiness or unsteadiness, particularly of the hands. This tends to get better when the medication dosage is reduced.
  
  
• Rash. Many mood stabilizers may cause a rash or acne. Medication may be discontinued depending on the type of mood stabilizer used and the severity of the rash. For instance, the anticonvulsants carbamazepine and lamotrigine are often discontinued if a rash occurs, because rashes can become severe or progress to Stevens-Johnson syndrome, a potentially fatal skin disease.
  
  
• Changes in blood chemistry. Most mood stabilizers require frequent blood tests to monitor chemical and compositional levels (e.g., calcium levels, white blood cell count, red blood cell count). Most of these changes are harmless, but some can be quite dangerous. Valproate can reduce the ability of the blood to clot in some patients. In rare cases, carbamazepine can result in significant and dangerous drops in levels of white or red blood cells.

Some side effects of lithium include:

• Headache and back pain
• Fatigue
• Weight gain
• Hair thinning and loss
• Increased urination and thirst
• Memory impairment
• Hypothyroidism (underactive thyroid)
• Osteoporosis (deterioration of bone)
• Hypertension (high blood pressure)
• Progressive deterioration of the kidney (rare)

Other side effects of anticonvulsant mood stabilizers include:

• Drowsiness
• Weight gain
• Hair loss
• Dizziness
• Lack of coordination
• Blurred vision