Akathisia is a neuropsychiatric disorder that causes both intense feelings of restlessness and repetitive limb movement, according to Current Psychiatry. It is most commonly a side effect of antipsychotic medication, although substance abuse disorders or withdrawal from an antipsychotic can also cause it.
Typically, akathisia causes restlessness in the legs, with many patients exhibiting involuntary leg shifting, foot shifting, pacing, fidgeting and leg crossing, notes Current Psychiatry. The symptoms of akathisia often overlap with those of other psychiatric disorders, making it difficult to properly diagnose. It occurs in both acute and chronic forms, and it may increase dysphoria, anxiety and suicidal ideation.