Research Helps Demystify Tardive Dyskinesia

We all know that exposure to certain medications, primarily dopamine receptor blocking agents (DRBAs), can lead to tardive dyskinesia (TD).

The incidence of TD varies, but analysts figure that it affects 15 percent to 40 percent of U.S. patients taking DRBAs. It manifests through involuntary movements such as stereotypies, dystonia, myoclonus, akathisia, and chorea, impacting various body parts and functions.

What’s less understood is how to forecast it accurately, assess it efficiently, and treat it effortlessly.

To that end, The Journal of Clinical Psychiatry has published several papers over recently that attempt to answer these lingering questions. Here are summaries as well as links to these studies for further review.

Survey Reveals Tardive Dyskinesia’s Sweeping Impact

In April of last year, JCP published a study that examined the overall impact of tardive dyskinesia (TD) on U.S. patients across physical, psychological, social, and professional domains.

Working from April 2020 to June 2021, researchers drafted and distributed an online survey aimed at TD patients aged 18 and older with co-existing schizophrenia, bipolar disorder, or major depressive disorder (MDD). The teams tasked participants with grading the seven-day impact of TD using Likert scales. They also had them fill out the Work Productivity and Activity Impairment Questionnaire.

Results from the 269 respondents exposed a substantial burden across the board, with schizophrenia patients reporting the highest severity.

TD also significantly hampered work productivity, with employed patients experiencing considerable absenteeism (29.1 percent) and presenteeism (68.4 percent). More than a third of patients reported altering or discontinuing antipsychotic medication because of their TD, which undermined the effective management of their underlying condition. Coping mechanisms included both nonpharmacologic strategies and medication use.

The study underscores the profound and diverse impact of TD and highlights the importance of prioritizing TD in treatment decisions for underlying psychiatric conditions.

Future research should explore interventions to mitigate TD’s burden and boost patient outcomes.

A New Clinical Tool for Gauging Tardive Dyskinesia

Accurate TD diagnosis remains crucial for identifying patients who could benefit from treatment, especially with the availability of FDA-approved medications. However, existing assessment tools, such as the Abnormal Involuntary Movement Scale (AIMS), have limitations.

To address these limitations, researchers developed a new diagnostic tool – the Clinician’s Tardive Inventory (CTI). Their goal? To better assess TD symptoms and their functional influence. It includes six anatomically defined symptom domains and rates symptom frequency and functional impairments on a scale from 0 to 3. The designers developed CTI to be user-friendly for clinicians of varying expertise levels and to facilitate documentation of TD examinations.

Subsequently, researchers conducted a study to evaluate CTI’s reliability. Expert clinicians assessed video recordings of TD examinations using the CTI, which revealed “good to excellent” reliability in identifying TD symptoms and functional impairments. They also determined that test-retest reliability also appeared to be “fair to very good.”

However, they also identified some challenges related to assessing subjective experiences such as symptom bother, which dampened reliability scores.

Despite limitations – whether it’s a heavy reliance on video assessments or variations in symptom presentation – the CTI showed promise.

The study authors add that future studies could help validate the CTI further and compare it to existing assessment scales. Additionally, efforts to develop updated versions of existing scales like AIMS are already underway to address the evolving understanding of TD phenomenology.

Do Long-Acting Injectable Antipsychotics Offer Relief?

In August 2002, JCP published a paper that attempted to investigate the association between long-acting injectable antipsychotics (LAI-APs) and TD using the Japanese Adverse Drug Event Report database.

The authors pulled data from April 2004 to February 2021. The teams sorted through info from nearly 8,500 patients who received LAI-APs or equivalent oral antipsychotics (O-APs). Specifically, the team focused on LAI haloperidol, fluphenazine, aripiprazole, risperidone, and paliperidone.

The study results suggested that TD patients reported significantly fewer symptoms with LAI paliperidone compared to oral paliperidone. Other LAI-APs showed numerically lower reporting frequency of TD compared to equivalent O-APs.

Additionally, the researchers linked:

• LAI second-generation antipsychotics (LAI-SGAs) to a significantly lower reporting frequency of TD than LAI first-generation antipsychotics (LAI-FGAs).
• LAI-SGAs to significantly lower TD symptom frequency than LAI fluphenazine.
• LAI fluphenazine to a higher reporting frequency of TD than LAI haloperidol.

Additionally, they found that LAI paliperidone had a significantly lower reporting frequency of TD compared to LAI aripiprazole.

Finally, the study authors acknowledged limitations, including inherent biases in the database, inability to accurately evaluate TD risk, and lack of detailed antipsychotic treatment data. Despite this, the findings suggest that LAI-APs, particularly LAI-SGAs, might carry a lower risk of TD compared to O-APs.

However, clear evidence regarding the association between LAI-APs and TD severity remains elusive, and the authors suggested that clinicians monitor TD development closely during LAI-AP treatment.

Further Reading

Diagnostic and Treatment Fundamentals for Tardive Dyskinesia

Prevalence of Tardive Dyskinesia in an Electronic Medical Record Study at a Large Community Mental Health Treatment Center

Measurement-Based Diagnosis and Treatment for Tardive Dyskinesia