Multidimensional sensory phenomena in antipsychotic-induced akathisia

The primary distinguishing features of akathisia in comparison with other extrapyramidal syndromes are the prominent subjective manifestations, which include various sensory symptoms. The sensory symptoms are multidimensional in nature and encompass various forms of bodily and mental sensations. The purpose of the present study was to elucidate the multidimensional aspects of the sensory phenomena associated with antipsychotic-induced akathisia. Seventy stable and chronic schizophrenic subjects receiving maintenance antipsychotic treatment were evaluated for akathisia and other extrapyramidal side effects. Subjective sensory phenomena were evaluated in 3 dimensions (ie, bodily sensations, mental sensations, and autonomic sensations). The frequency of each dimension of these sensory phenomena was compared between the groups with and without akathisia using chi test with Bonferroni correction. The akathisia group (n = 29) reported significantly more frequent focal or generalized bodily sensations than the non-akathisia group (n = 41) (P < 0.001). The akathisia group also showed significantly more frequent mental sensations such as mental urge and a feeling of inner tension/pressure (P < 0.001). In autonomic phenomena, there was a trend for the akathisia group to show more frequent autonomic sensations. The most common autonomic phenomena associated with akathisia were palpitation and difficulty breathing. The results of the present study suggest that the sensory phenomena of antipsychotic-induced akathisia are characterized by multidimensional features such as bodily sensations, mental sensations, and several autonomic sensations. The assessment of these multidimensional sensory phenomena would be useful in evaluating the important phenotypic features of akathisia.