Akathisia: Definition, Causes, and Clinical Relevance in Mental Health

Akathisia is a psychomotor syndrome characterized by a subjective sense of inner restlessness and an overwhelming, often distressing urge to move. The term derives from the Greek a- (without) and kathisis (sitting), literally meaning "inability to sit." Individuals experiencing akathisia frequently pace, shift weight from foot to foot, rock while seated, or cross and uncross their legs repeatedly. Critically, akathisia is not simply physical agitation — it involves a deeply uncomfortable internal sensation that patients often describe as feeling "crawling out of my skin" or an unbearable need to keep moving.

Akathisia is most commonly encountered as an adverse effect of psychotropic medications, particularly antipsychotic drugs (both first-generation and second-generation), though it can also occur with SSRIs, SNRIs, antiemetics, and other dopamine-blocking agents. It is classified among extrapyramidal symptoms (EPS) — a group of movement disorders caused by disruption of dopaminergic pathways in the basal ganglia.

Akathisia can be categorized by timing of onset:

• Acute akathisia: Develops within days to weeks of starting or increasing a medication
• Tardive akathisia: Emerges after prolonged medication use (months to years) and may persist even after the causative drug is discontinued
• Withdrawal akathisia: Occurs upon reduction or discontinuation of a medication

Prevalence estimates vary widely depending on the medication and population studied, but research suggests that 20–45% of patients taking first-generation antipsychotics experience some degree of akathisia. Second-generation antipsychotics carry a lower but still significant risk.

Akathisia is clinically significant for several reasons. First, it is a leading cause of medication nonadherence — the distress it produces can be so severe that patients discontinue treatment without guidance, risking relapse of the underlying psychiatric condition. Second, akathisia is frequently misdiagnosed as worsening anxiety, psychotic agitation, or behavioral disturbance, which can lead clinicians to increase the very medication causing the problem. Third, emerging evidence links untreated akathisia to increased suicidal ideation, aggression, and emotional dysregulation, making accurate identification essential for patient safety.

Assessment tools such as the Barnes Akathisia Rating Scale (BARS) help clinicians distinguish akathisia from other causes of restlessness and quantify its severity.

• Extrapyramidal symptoms (EPS): A broader category of movement disorders caused by dopamine-blocking drugs, including dystonia, parkinsonism, and tardive dyskinesia
• Tardive dyskinesia: Involuntary, repetitive movements (especially of the face and tongue) resulting from long-term antipsychotic use
• Psychomotor agitation: A state of restless, purposeless physical activity driven by mental tension — overlaps symptomatically with akathisia but has different causes
• Restless legs syndrome (RLS): A neurological condition involving uncomfortable leg sensations and an urge to move, primarily at rest and during the evening; distinct from akathisia but sometimes confused with it

Anyone who experiences new-onset restlessness, an inability to sit still, or intense inner discomfort after starting or changing a psychiatric medication should contact their prescribing clinician promptly. These symptoms should never be ignored or self-managed by abruptly stopping medication. A qualified provider can evaluate whether the experience is consistent with akathisia and adjust the treatment plan accordingly — options may include dose reduction, medication switching, or the addition of adjunctive agents to manage symptoms.