What is Akathisia?
Akathisia is a movement disorder characterized by severe inner restlessness and an urgent need to move, commonly manifesting as pacing, rocking, or fidgeting—most frequently caused by antipsychotic medications and often misinterpreted as worsening psychiatric symptoms or anxiety. 1, 2
Clinical Presentation
Akathisia consists of both subjective and objective components that must be recognized to avoid misdiagnosis:
Subjective symptoms:
- Inner restlessness and mental unease 2
- Urgent, compelling need to move 2
- Dysphoria and significant distress 3
- Critical distinction: absence of constant pain (if constant pain is present, consider alternative diagnoses like musculoskeletal pain or dystonia) 2
Objective motor signs:
- Pacing or inability to remain seated 4
- Rocking while standing or sitting 5
- Shifting weight from foot to foot 4
- Crossing and uncrossing legs repeatedly 5
- Marching in place or shuffling feet 6
Common Causes and Risk Factors
Antipsychotic medications are the primary culprit, with prevalence rates of 5-36.8% among treated patients 2, 5. Importantly, even second-generation antipsychotics with minimal extrapyramidal effects (clozapine, quetiapine, aripiprazole, cariprazine) can induce akathisia 3.
Other causative medications include:
- SSRIs, particularly fluoxetine (associated with increased suicidality risk) 1, 2
- Antiemetics like metoclopramide and prochlorperazine 6
- SNRIs, stimulants, mirtazapine, and tetrabenazine 3
High-risk populations:
- Children and adolescents (higher risk than adults) 1, 7
- Young males (increased risk for acute dystonic reactions) 1
- Patients with history of dystonic reactions 8
Critical Diagnostic Pitfall
The most dangerous error is misinterpreting akathisia as psychotic agitation, anxiety, or worsening psychiatric illness, which leads clinicians to inappropriately increase the causative antipsychotic dose—thereby worsening the condition 8, 1, 2. This is a common reason for medication noncompliance and can lead to aggression, violence, and suicide in severe cases 2.
How to Assess Akathisia
Use the Barnes Akathisia Scale to systematically evaluate and objectively track symptoms 2. Differentiate from restless legs syndrome, which specifically involves unpleasant leg sensations that worsen at rest and improve with movement 2.
Treatment Approach
First-Line Management
Reduce or discontinue the offending medication if clinically feasible 8, 1, 7. If antipsychotic continuation is necessary, switch to lower-risk agents like quetiapine or olanzapine 1, 7.
Pharmacological Treatment Algorithm
Step 1: Beta-blockers (most consistently effective)
- Propranolol 10-30 mg two to three times daily is the gold standard 1, 5, 9
- Other lipophilic beta-blockers are alternatives 5
Step 2: Benzodiazepines (if beta-blockers fail or for anxiety component)
- Clonazepam provides symptomatic relief and addresses anxiety 1, 9
- Particularly useful when subjective distress persists 5
Step 3: Mirtazapine (low-dose)
- Well-studied alternative with good evidence 3, 9
- Serotonin 2A receptor antagonist properties may be beneficial 4
Step 4: Additional options if above fail
- Amantadine (mild dopaminergic agent, limited evidence) 1, 5
- Gabapentin or pregabalin (voltage-gated calcium channel blockers) 3
- Clonidine 5, 9
Important caveat: Anticholinergic agents (benztropine, trihexyphenidyl) are NOT consistently helpful for akathisia specifically, despite being effective for other extrapyramidal symptoms like dystonia and parkinsonism 8, 1, 7. They should be avoided, especially in patients with underlying Parkinson's disease 7.
Special Considerations
SSRI-induced akathisia carries critical suicide risk, particularly with fluoxetine—systematically assess suicidal ideation before and after treatment initiation 1, 2.
Prophylactic antiparkinsonian agents should not be routinely prescribed except in high-risk patients (history of dystonic reactions, paranoid patients with compliance concerns) 8, 1, 7. Reevaluate need after the acute phase, as many patients no longer require them during long-term therapy 8, 1.
In patients with underlying Parkinson's disease, avoid anticholinergics and focus on beta-blockers or benzodiazepines for symptomatic relief 7.