¹Ministry of Health of Türkiye, Department of Child and Adolescent Psychiatry, Kocaeli, Turkey

Background: Restless Leg Syndrome (RLS) is a neurological disorder that causes an urge to move the legs, accompanied by unpleasant sensations. Symptoms worsen during rest and improve with movement. It affects %5 of the population. The exact cause of primary RLS is unknown, but some theories suggest that it could be related to problems with iron metabolism or abnormal dopamine neurotransmission. Various psychotropic drugs have been known to cause drug-induced forms (1).

Aims & Objectives: To present a case of risperidone-induced RLS in an adolescent and to highlight the potential therapeutic role of aripiprazole, a dopamine D2 partial agonist.

Method: An 17-year-old female patient was admitted to our outpatient clinic with complaints of depressed mood, anhedonia, fatigue, and difficulty falling asleep, which had been going on for one month. Laboratory investigations, including serum iron, ferritin, serum electrolytes, and thyroid function tests, were performed at this stage and did not reveal any abnormality. She, who had no comorbidities, was diagnosed with major depressive disorder and was started on fluoxetine 20 mg/day. In the interview two weeks later, when it was learned that the self-harming behaviour had been occurring for the last two months, an additional risperidone 1 mg/day was started. In an examination two weeks later, she stated that his depressive complaints had partially regressed. Still, it was learned that she had a feeling of restlessness that decreased when she moved her legs, which started three days after starting risperidone. It was understood that this feeling occurred only at night, and when she moved her legs, her discomfort subsided quickly. Since the patient’s mother also had a history of RLS and had no obvious symptoms during the day, RLS, not Akathisia, was considered as the diagnosis. Risperidone was discontinued, and aripiprazole 5 mg/day was started.

Results: Following the initiation of risperidone, the patient developed nocturnal symptoms consistent with RLS, characterised by an urge to move the legs and relief with movement. Discontinuation of risperidone and initiation of aripiprazole 5 mg/day led to complete resolution of RLS symptoms within three days.

Discussion & Conclusions: Although RLS’s aetiology is unclear, neuropathological studies have shown significant decreases in dopamine D2 receptors in the putamen [2]. A study indicates that risperidone, which has a D2 receptor antagonistic effect, can lead to the development of RLS [3]. Aripiprazole is a drug that has been linked to both causing and improving symptoms of RLS. However, it is believed that aripiprazole can be used as a treatment for RLS because it is a partial agonist of D2 receptors. These receptors are thought to play a role in developing RLS [4]. Although both akathisia and RLS share some similarities, in this particular case, the symptoms appeared only at night, the dysesthesia reduced with movement, and the patient's mother had a history of RLS, which suggests RLS is the more likely diagnosis [5] It was concluded that clinicians should be alert for the development of RLS after antipsychotic use and that aripiprazole can be used as an alternative treatment because its dopamine activity is specific.