Irritability can occur in HD before motor symptoms and at all stages of disease after motor diagnosis. It can take the form of impatience, intolerance and reduced control over temper, and difficulty in letting go of the anger. Individuals experience irritability differently: some "feel" irritable, some express mild irritability, while in others it can escalate to anger and physical aggression. Early recognition and treatment of irritability is vital for prevention of more severe behaviors.

Irritability does not increase with disease duration.

Irritability often co-occurs with other symptoms including depression, anxiety, obsessive compulsive behaviors (perseveration). Irritibility interferes with sleep and poor sleep in turn can cause irritability. Frequently irritability may be the result of frustration due to the increased difficulty the individual experiences with performing routine physical and mental tasks or being unable to communicate needs such as hunger or pain.

Clinical Practice Guidelines for Irritability in HD Note that this author has changed some of the wording that appears in the journal article for purposes of making it more user friendly. If you wish to share with your medical provider, it would be best to copy the journal link [Groves M 2011] for the doctor's review.

General recommendations

  1. Make sure irritability is not being caused by factors not related directly to HD. (Fever, infection, trauma, new drug, etc)
  2. Identify and promptly treat other neuropsychiatric symptoms of HD (depression, anxiety, obsessive perseverative behaviors and poor sleep) that can cause or worsen irritability behaviors
  3. Identify and modify environmental factors like excessive noise or other over-stimulation, or unmet needs such as hunger or pain that may have caused irritability

Behavior recommendations

  1. Provide educational information about strategies that may lessen or prevent irritability (keep to routines, don't over-stimulate, maintain personal space. (The medical provider should help identify a cause for irritabilty behaviors and recommend changes)
  2. The first step in treating irritability is to provide a quiet and safe place to calm down

Drug recommendations (note that treatment of severe irritabilty (agitation) is different that of milder irritability symptoms)

  1. For severe irritability that has progressed to agitation that is not responding to calming down strategies, a benzodiazepine like lorazepam (Ativan®) or an antipsychotic like olanzapine (Zyprexa®) or haloperidal (Haldol®) can be used short-term
  2. For milder expressions of irritability, the first choice drug is an SSRI (like sertraline (Zoloft®) or citalopram (Celexa®) whether it occurs as a single symptom or occurs with depression, anxiety or obsesseive perseverative behaviors (because this type of drug treats all three of these symptoms)
  3. Warning should be given that anxiety may worsen briefly after starting an SSRI. (Best to start with a low dose). If worsening of anxiety occurs when starting an SSRI, adding a benzodiazepine short term may be helpful
  4. If the initial SSRI is not helpful or gives unacceptable side effects, alternative SSRI drugs (a different SSRI, or an NSRI like venlafaxine (Effexor®)) should be tried
  5. If SSRI drugs have failed or not been tolerated, an antipsychotic is the alternative next choice
  6. Mirtazapine (Remeron®) is an option particularly if sleep disorder is present
  7. Clomipramine (Anafranil®) is an option particularly if severe obsessive perseverative symptoms are present
  8. The long term use of a benzodiazepine is discouraged in ambulatory individuals (due to increased risk of confusion and falls) unless all other options have failed

It is important to remember (as in the general recommendations) that drugs used for the treatment of irritability are associated with side effects like apathy, slowed thinking, slowed movement, trouble swallowing and loss of balance leading to falls. A trial of tapering antipsychotic drug is indicated in most situations once irritabiliy has been calmed.

Author's Take Home Points

Early treatment of irritability is the treatment goal for prevention of more severe behaviors. The importance of identifying triggers of irritability behaviors (using a little detective work) is vital. Addressing and modifying the causes of irritability is vital. Treatment often requires a combination of behavior modification and drugs. And if irritability is mild, always start with an SSRI, reserving the antipsychotic for more severe behaviors. Though it cannot be prevented totally, early treatment of irritabilty can reduce the frequency and severity of more extreme and aggressive behaviors. 

References

Groves M, van Duijn E, Anderson K, Craufurd D, Edmondson MC, Goodman N, van Kammen DP, Goodman L. An International Survey-based Algorithm for the Pharmacologic Treatment of Irritability in Huntington's Disease. PLoS Curr. 2011 Aug 30;3:RRN1259. PubMed abstract