Psychosis in HD is defined by the presence of delusions and/or hallucinations that are not caused by other illness (like infection or trauma) that can have features of psychosis with confusion. Psychosis of HD is reported less commonly than other neuropsychiatric symptoms in HD, but some experts thought it may be underdiagnosed. Psychosis is a severe symptom that imposes significant burden on both the individual with HD and carers. Its treatment in HD is similar to treatment of psychosis in other diseases.

Clinical Practice Guidelines for Psychosis in HD

General Recommendations

  1. Identify and treat medical reasons for psychosis (like infection, trauma, toxins, drug or substance use, etc)
  2. Identify and treat other neurospychiatric symptoms of HD (like sleep disorders and obsessive perseverative behaviors) that can impact the severity of and distress caused by psychosis in HD
  3. Identify and modify external factors that can contribute to the distress of psychosis (excessive noise or overstimulation, pain, unmet needs)

Drug Recommendations

  1. An antipsychotic drug is first-line treatment for psychosis in HD. (Though most experts (83%) preferred the newer 2nd generation drugs, others used first generation drugs particularly if chorea was problematic)
  2. If the first antipsychotic drug does not adequately treat psychosis, an alternative antipsychotic should be used
  3. Clozapine (Clozaril®) should be used only after other antipsychotics have failed, and only in situations where interval blood testing is performed
  4. Higher than drug company recommended doses of an antipsychotic drug is discouraged
  5. Combining of antipsychotics is discouraged except in severe presentations of psychosis
  6. If symptoms of psychosis improve, consider lowering the dose of antipsychotic (because drug side effects cannot be differentiated from disease progression)

Authors comment: Experts also suggested that the goal of treating psychosis in HD is to decrease the severity of distress for the individual with HD or carers. Lower grade psychotic symptoms often persist despite adequate treatment. Over use of antipsychotics in this situation, and treatment with multiple antipsychotics at the same time occurs with some frequency in long term care facilities.