Weight gain and bipolar disorder meds

Is there a medication for bipolar disorder that won’t cause weight gain?

The majority of  medications that are used to treat BPD cause weight gain. The only ones that do not cause significant weight gain are the anticonvulsants, but they are not always effective. In addition, the anticonvulsants have other adverse effects like sedation, excess fatigue and drowsiness. BPD is a very difficult disorder to treat because the patients are often non compliant and have other associated disorders. My advice is take the drug given to you by your doctor and if it works, stay with it. In many cases, what works in one patient does not mean it will work for you. 

There is no way around the side effects of antipsychotics; every single medication used to treat mood and behavior disorders is associated with side effects. To avoid weight gain, eat less and walk more.