A 38-year-old female client with a history of chronic schizophrenia, paranoid type, is currently an outpatient at the local mental health and mental retardation clinic. The client comes in once a week for medication evaluation and/or refills. She self-administers haloperidol 5 mg twice a day and benztropine 1 mg once a day. During a recent clinic visit, she says to the nurse, I can't stay still at night. I toss and turn and can't fall asleep."The nurse suspects that she may be experiencing:"