A previously healthy 15 year-old female presented with behavioral changes with incoherent speech, restlessness, anxiety, and expressed the feeling that “everything is happening to me” after attending a 2-day spiritual retreat. One week before the presentation of psychiatric symptoms, she had unspecific common cold symptoms, but with no fever. On the second day of psychiatric presentation, she had a transient period of agitation and visual hallucination with spontaneous remission (she saw Jesus and her deceased grandparents). On the third day, she was brought to the emergency room (ER), for the first time, owing to an episode of agitation and speech blockade that happened at school. Concomitantly, she had somatic manifestations, such as swallowing impairment, odynophagia for water and food refusal. She showed regressive behavior, such as asking for help for basic hygiene and refusal to sleep alone. At this point, episodic speech changes, such as echolalia and verbal perseveration and intermediary insomnia were documented. Of note, there were no changes in the flow of thoughts or indication of disorganized behavior. The patient was medicated with risperidone (0.5 mg once a day) by the ER child and adolescent psychiatry attendant, and referred to the Child and Adolescent Psychiatry Outpatient Clinic. However, a few hours later, she was re-admitted in the pediatric ER with panic symptoms (tachypnea, tachycardia, shaking hands, and sweating). She was discharged and medicated with lorazepam (0.5 mg two times a day) and risperidone (1 mg once a day) with no improvement, namely, the visual hallucination persisted. At the first child and adolescent psychiatry outpatient appointment (day 7 after symptoms onset), she was oriented, and presented with unexpressive facial mimicry, provoked speech, and psychomotor retardation. No changes in the form, rhythm or flow of thoughts, or delusions were documented. The patient had anxiety with no mood changes, although she had a regressive attitude. The patient was medicated with anxiolytics (diazepam 5 mg two times a day), and risperidone (1 mg) was increased to twice daily. At the next child and adolescent psychiatry appointment (day 10 of the disease), she maintained episodes of agitation with tremor of the upper limbs, screaming, and a desperation gaze that was attributed to hallucinations, according to her family. During these episodes, the patient said that “they are after me (…) I am a saint (…) nobody will survive…”. On other occasions she would experience periods of elation, with tendency to sing and express grandiose delusions: “I will be the best student at my class”. During the mental state examination she was extremely sleepy, calm with provoked speech, and answered with monosyllables. Therapy was adjusted, and risperidone was replaced with olanzapine (10 mg once a day). She was recommended for hospital admission, but the patient’s family refused this recommendation. On day 18 of the disease, with no signs of clinical improvement, the patient was brought to a new appointment, and admitted in a psychiatry ward. At admission she was oriented to time, place, person and situation but showed periods of negativism, mutism, echolalia, echopraxia, motor agitation, upper limb tremor (that occurred at rest, with sudden onset and remission and disappeared when she was distracted), These symptoms occurred in bursts alternated with periods of normal speech but with pervasive prostration. Also, she was unable to take care of her own hygiene. At physical examination she did not have fever or changes in blood pressure, and cardiac or respiratory frequency. Pulmonary and cardiac auscultation were unremarkable, abdomen examination was also normal, and at the examination she had no changes of the skin and upper and lower limbs. At that point, the following diagnostic hypotheses were considered: prodromal phase of an affective psychosis, anxiety disorder with conversion traits, dissociative disorder (depersonalization disorder), organic disorder, and psychosis with catatonic features. Due to the catatonic symptoms, the diagnosis of neuroleptic malignant syndrome was also raised and a possible treatment with dopamine agonist was considered. However, this specific intervention was deferred since the patient had no fever or changes in the blood pressure, cardiac or respiratory frequency or laboratory imbalance. The diagnostic hypotheses were based on the clinical presentation, physical examination, and mental state examination. We did not apply the mini-mental state examination or any other rating scale for psychosis, mood, cognitive or neurologic symptoms. Laboratory results and brain CT scan were normal. Psychiatric medication for psychosis was started. At day 5 after admission (day 23 of clinical disease), a lumbar puncture was performed with screening for antibodies for anti-NMDA receptors in the spinal fluid. Since the hypothesis of anti-NMDA receptors encephalitis was raised, it is mandatory to first rule out possible underlying neoplasm. Because the patient was female and ovarian teratoma can occur in up to 59 % of cases [], a pelvic ultrasound was performed, but no changes were found. On the same day, the patient experienced tachycardia and decreased consciousness, with the need for intensive care unit (ICU) admission. No rating scale was applied during the stay in the intensive care unit. However, antibodies for NMDA receptors were detected and diagnosis of anti-NMDA receptor encephalitis was established. At the ICU the patient experienced periods of delusion and agitation with loud screaming. She was medicated with midazolam (2 mg intravenous if needed), oral lorazepam (1 mg three times a day), and chloral hydrate (1 g every 6 h). Within the first few hours, risperidone was introduced at 0.5 mg daily and then titrated to 1 mg daily. She was subsequently treated with immunoglobulin (2 mg/kg/day), methylprednisolone (30 mg/kg/day), and plasmapheresis and rituximab (375 mg/m2/week). Regarding the maintenance psychopharmacology, the patient was on risperidone (1 mg two times a day) and lorazepam (2.5 mg if needed). Two months after specific treatment for anti-NMDA receptor encephalitis, the patient still had difficulty with verbal articulation, but there were no changes regarding form, course, rhythm or thought content, and her mood was euthymic. She reported periods of emotional lability, although less frequent than before treatment, and there were no auditory or visual hallucinations. She reported moderate verbal memory impairment, attention and concentration difficulties at school. Although a formal neuropsychological evaluation was not performed, it was known that before disease onset, the patient had no cognitive difficulties at school since her IQ was considered within the normal range, and her grades were average. She started psychotherapy, physiotherapy, and learning support at school. She had progressive clinical improvement but still experienced emotional lability, anxiety, and verbal memory impairment, attention and concentration difficulties at school that justified her enrolment in a vocational educational school. Ten months later she had a seizure episode and a new treatment cycle was started. Since she experienced depressive symptoms after the encephalitis episode, sertraline (25 mg once a day) was added to her medication regimen. As of this writing, she is medicated with oxcarbazepine (450 mg two times a day), quetiapine SR (100 mg at bedtime), sertraline (25 mg once a day) and lorazepam (1 mg if needed). Also as of this writing (almost 3 year after the disease onset), the patient’s psychiatric symptoms have improved, but she still experiences verbal memory impairment, and attention and concentration difficulties.