Researchers of a longitudinal study of 200 patients in remission from first-episode psychosis examined whether antipsychotic plasma concentrations could better predict movement disorders and cardiometabolic adverse effects than prescribed doses. Over a median follow-up of 6 months, higher plasma concentrations were associated with greater odds of parkinsonism (odds ratio, 1.81; 95% confidence interval, 1.27-2.57), while no significant associations were found with tardive dyskinesia, akathisia, or tardive dystonia. Plasma concentrations also showed moderately better predictive performance than prescription dose for identifying parkinsonism risk. This suggests that therapeutic drug monitoring may provide clinically useful information beyond dose alone for some patients.

The findings were more nuanced for cardiometabolic effects. Among patients taking olanzapine, higher plasma concentrations were associated with greater odds of parkinsonism as well as higher glucose, total cholesterol, and non-high-density lipoprotein cholesterol levels. However, prescription dose generally predicted several cardiometabolic outcomes better than plasma concentration. The authors suggest that therapeutic drug monitoring may be most useful for evaluating antipsychotic-related parkinsonism, particularly with agents associated with higher parkinsonism risk, rather than for managing cardiometabolic adverse effects. Interpretation is limited by the modest sample size, relatively few repeated measurements for many participants, and insufficient numbers to analyze most individual antipsychotics separately.

Reference: Liu Y, Sommer IE, Schoretsanitis G, et al. Antipsychotic plasma concentration as predictor of movement disorders and cardiometabolic side-effects: A comparison with prescription dose. Eur Neuropsychopharmacol. 2026 Apr;105:112769. doi: 10.1016/j.euroneuro.2026.112769. 

A large real-world study compared adults with tardive dyskinesia (TD) who initiated a vesicular monoamine transporter 2 (VMAT2) inhibitor with those who initiated an anticholinergic agent. After propensity-score matching, 2,749 patients were included in each group. VMAT2 inhibitor use was associated with significantly lower risks of falls (HR, 0.83), injuries (HR, 0.77), fractures (HR, 0.82), and mortality (HR, 0.71). Secondary outcomes also favored VMAT2 inhibitors, including lower risks of delirium, dementia, and arrhythmia. The findings are particularly relevant because anticholinergics remain commonly prescribed despite not being considered evidence-based treatments for TD and may worsen tardive symptoms in some patients.

For nurse practitioners and physician associates managing adults with TD, the results highlight the importance of considering broader safety outcomes when evaluating treatment strategies, especially in older patients or those already at risk for falls, cognitive impairment, or polypharmacy. Associations generally remained consistent across sensitivity analyses and age and sex subgroups, although some subgroup estimates were not statistically significant. Because the study relied on retrospective electronic health record data, residual confounding remains possible, including the possibility that anticholinergics were prescribed for coexisting drug-induced parkinsonism rather than TD itself. The authors therefore call for longer-term, prospectively validated research before concluding that VMAT2 inhibitors directly reduce these adverse outcomes.

Reference: Hsu TW, Hsu CW, Tseng PT, et al. Adverse outcomes between VMAT2 and anticholinergics in tardive dyskinesia: A target trial emulation. Psychiatry Clin Neurosci. 2026 Aug;80(8):637-644. doi: 10.1111/pcn.70056.

Real-world data from the ongoing IMPACT-TD Registry suggest that tardive dyskinesia (TD) can carry substantial burden across adulthood, including in younger patients with mood disorders. Among 211 VMAT2 inhibitor-naïve adults with TD and concomitant mood disorders, moderate-to-severe global impact was reported across age groups and was especially high among adults aged 18 to 29 (85%) and 50 to 59 (87%). Psychological impact was also pronounced in younger adults: 77% of those aged 18 to 29 reported moderate-to-severe psychological effects despite having lower mean Abnormal Involuntary Movement Scale scores than older groups.

The findings also point to a potential recognition and diagnosis gap in younger patients. Only 23% of participants aged 18 to 29 and 35% of those aged 30 to 39 had a formal TD diagnosis, compared with higher rates in older groups, and the average interval from recognition of involuntary movements to formal diagnosis exceeded 3.5 years. Although the youngest subgroup was small (n=13), the results suggest that TD burden may not always track with movement severity alone and reinforce the importance of screening for functional and psychological impact, not just visible symptoms, across the adult age spectrum.

Reference: Kuntz L. New Data From IMPACT-TD Registry: Only 23% of Young Adults With Mood Disorders and Tardive Dyskinesia Symptoms Are Formally Diagnosed. Psychiatric Times. Published May 18, 2026. Accessed September 4, 2026. https://www.psychiatrictimes.com/view/new-data-from-impact-td-registry-only-23-of-young-adults-with-mood-disorders-and-tardive-dyskinesia-symptoms-are-formally-diagnosed