Apathy Symptoms:  Apathy is a symptom that occurs in at least 50% or more of HD people [Paulsen 2001].  Symptoms include lack of interest and motivation, inability to start activities, social withdrawal, and emotional flatness. Though many of these symptoms are similar to those that occur in depression, apathy is often present in HD even after depression is treated.  Studies in HD mice suggest that treatment of insomnia will lessen apathy [Pallier 2007].

Apathy Treatments:  Antidepressants should always be used because depression may be causing or worsening apathy symptoms. Even when depression is not present, treatment with antidepressants can treat apathy directly, at least in other neurologic diseases like Alzheimer's and Parkinson's [Boyle 2004]. Improving sleep patterns with sedative drugs may be helpful.  In other studies, psychostimulant or activating drugs (like Ritalin® and Dexedrine®) have been helpful in Parkinson's [Chatterjee 2002], and Alzheimer's [Jansen 2001], but have not been studied in HD.  Atomoxetine (Strattera®) is a psychostimulant drug that is being studied primarily for cognitive benefit in an ongoing clinical trial for Huntington's.

Stimulant drugs can increase anxiety, irritability and cause agitation. Close follow-up with your doctor is important. There can also be loss of appetite, elevation of blood pressure and headache.

Commonly Used Apathy Medications

Atomoxetine (Strattera®): This is a selective norepinephrine reuptake inhibitor. Doses start at 40 mg/day and are increased slowly over weeks of time. If this drug is used with paroxetine (Paxil®) or fluoxetine (Prozac®), lower dose adjustment is necessary.

Dextroamphetamine (Dexedrine®): Dosages start at 10 mg/day, and can be increased in weekly intervals. This drug has high addictive potential.

Modafinil (Provigil®): Dosage starts as 100-200 mg/day. This drug is also used for treatment of fatigue in Multiple Sclerosis. Headache is a frequent side effect of higher dose therapy. This drug has lower side effect potential for agitation or insomnia.

References

Paulsen JS, Ready RE, Hamilton JM, Mega MS, Cummings JL. Neuropsychiatric aspects of Huntington's disease. J Neurol Neurosurg Psychiatry 2001 Sep;71(3):310-4. PubMed abstract

Pallier PN, Maywood ES, Zheng Z, Chesham JE, Inyushkin AN, Dyball R, Hastings MH, Morton AJ. Pharmacological imposition of sleep slows cognitive decline and reverses dysregulation of circadian gene expression in a transgenic mouse model of Huntington's disease. J Neurosci 2007 Jul 18;27(29):7869-78. PubMed abstract

Boyle PA, Malloy PF. Treating apathy in Alzheimer's disease. Dement Geriatr Cogn Disord 2004;17(1-2):91-9. PubMed abstract

Chatterjee A, Fahn S. Methylphenidate treats apathy in Parkinson's disease. J Neuropsychiatry Clin Neurosci 2002;14(4):461-2. PubMed abstract

Jansen IH, Olde Rikkert MG, Hulsbos HA, Hoefnagels WH. Toward individualized evidence-based medicine: five "N of 1" trials of methylphenidate in geriatric patients. J Am Geriatr Soc 2001 Apr;49(4):474-6. PubMed abstract