Akathisia (IPA: /æ.kə.ˈθɪ.si.ə/) is a movement disorder[5] characterized by a subjective feeling of inner restlessness accompanied by mental distress and/or an inability to sit still.
[2] The most severe cases may result in poor adherence to medications, exacerbation of psychiatric symptoms, and, because of this, aggression, violence, and/or suicidal thoughts.
[4][7] Other agents commonly responsible for this side-effect may also include selective serotonin reuptake inhibitors, metoclopramide, and reserpine, though any medication listing agitation as a side effect may trigger it.
However, despite a lack of historical association between restless leg syndrome and akathisia, this does not guarantee that the two conditions do not share symptoms in individual cases.
[2] The antidepressant mirtazapine, although paradoxically associated with the development of akathisia in some individuals, has demonstrated benefit,[5] as have diphenhydramine, trazodone, benzatropine, cyproheptadine, and beta blockers, particularly propranolol.
[5] Symptoms of akathisia are often described in vague terms, such as feeling nervous, uneasy, tense, twitchy, restless, and unable to relax.
[1][2] Visible signs of akathisia include repetitive movements, such as crossing and uncrossing the legs and constant shifting from one foot to the other.
For example, while mania, agitated depression, and attention deficit hyperactivity disorder may present like akathisia, movements resulting from them feel voluntary, rather than being due to restlessness.
[17] Jack Henry Abbott, who was diagnosed with akathisia, described the sensation in 1981 as: "You ache with restlessness, so you feel you have to walk, to pace.
Even so, drugs with successful therapeutic effects in the treatment of medication-induced akathisia have provided additional insight into the involvement of other transmitter systems.
[24] Akathisia involves increased levels of the neurotransmitter norepinephrine, which is associated with mechanisms that regulate aggression, alertness, and arousal.
[5] The primary distinguishing features of akathisia in comparison with other syndromes are primarily subjective characteristics, such as the feeling of inner restlessness and tension.
[28][29] Akathisia can commonly be mistaken for agitation secondary to psychotic symptoms or mood disorder, antipsychotic dysphoria, restless legs syndrome, anxiety, insomnia, drug withdrawal states, tardive dyskinesia, or other neurological and medical conditions.