Mr. A was a 46-year-old single, male.
Chronic pain in the left maxillary and right mandibular molar regions (according to him, due to gingival recession caused by periodontal treatment), occlusal discomfort (specific teeth unidentified), extracted teeth, teeth sticking to the lips, occlusal instability, difficulty in opening the mouth, eating, and speaking.
None.
He began visiting a nearby dental clinic in 2018. On May 7, 2019, he was referred to the clinic of periodontics at the Tokyo Medical and Dental University dental hospital by the nearby dentist due to problems with oral hygiene instructions owing to complaints such as "gingival damage due to tooth brushing" and many other complaints (e.g., occlusal instability, difficulty eating, difficulty speaking). At the clinic, he mentioned that his teeth were sensitive to cold water and did not understand the explanation of the lack of identifiable causes requiring treatment. Thereafter, he had repeated unscheduled visits and phone consultations with the clinic to present with complaints such as "I feel some teeth are missing," "I can no longer chew with the left teeth." In July, periodontal scaling was initiated. However, his complaints increased and worsened (e.g., "gingival recession," a tingling sensation and numbness," and "the lower teeth are damaged by the upper teeth"). He began visiting the clinic approximately once or twice a week. During 3 months after August, he lost 20 kgs due to "hip pain" and "difficulty walking." From October, he was unable to work and took leave. The Department of Psychiatry, to which he was recommended by his younger sister, suspected he had somatic symptom disorder after excluding psychotic disorders, depression, and bipolar disorder. However, the psychiatric treatment was discontinued because he remained highly dissatisfied with the dental treatment.
On November 26, 2019, he visited our clinic (Department of Psychosomatic Dentistry) for the first time. However, the examination did not reveal any findings correlated with his complaints (Figure 1). Mr. A was diagnosed with AO, regarding that his pain was limited around his teeth (however, moving beyond nerve distribution), not provoked by jaw movement and failed to respond to every conventional dental treatment. However, based on the previous treatment process and his attitude, underlying developmental disorders were suspected. Hence, effects of amitriptyline and so on were not anticipated. He was referred to the outpatient department of SK, who is familiar with the treatment of developmental disorders in the Department of Anesthesiology, The University of Tokyo Hospital; at this point, the patient declined the referral.
However, given his continued complaint calls and letters regarding "incidents at the periodontics clinic" to the chief of periodontics clinic, our dental hospital director issued a treatment refusal document and send it to the patient in April. In response to our letter, the patient made repeated visits and phone consultations with our department, asking "What should I do with my teeth?" Therefore, he was advised to seek treatment at the University of Tokyo Hospital. Despite reluctance, on March 6, he eventually agreed to the referral. He was referred to Dr. SK a psychiatrist at the Department of Anesthesiology and Pain Relief Center, on April 24, 2020 (day 0). The timeline for this patient is shown in Figure 2. During the examination, he was suspicious of the treatment in the primary referral hospital and made unsolicited complaints without listening to the advice of Dr. SK. A structured interview, the Mini-International Neuropsychiatric Interview, was conducted to differentiate comorbid psychiatric disorders. He did not have a major depressive episode with hypochondriac delusions or other melancholy-type features, a manic episode, or psychotic disorder. He displayed gender-atypical gestures and abnormal eye contact and ritualized patterns of verbal or non-verbal behavior (his speech was excessively formal and polite). He was overly particular about Dr. SK's wording and frequently corrected his expressions. He had highly restricted and fixated interests in gingival pain and was hyperreactive to sensory input. Hence, he was diagnosed with ASD according to the diagnostic criteria of the DSM-5. He was highly educated and employed in a highly structured, professional occupation, and did not have severe impairment in social functioning due to ASD prior to the onset of AO.
Based on hyperactivity and impulsivity symptoms observed (fidgeting with hands and squirms in seat, blurting out answers, interrupts others), the long version of the Conners' Adult ADHD Rating Scale (CAARS-S) and the observer-rated (CAARS-O) questionnaire were administered to examine the suspected comorbidity of ADHD. Mr A's percentiles of the subscale of the CAARS-S were: E. DSM-IV Inattentive Symptoms, 90; F. DSM-IV Hyperactive-Impulsive Symptoms, 98; G. DSM-IV ADHD Symptoms Total, 96; H. ADHD Index, 88. According to ADHD symptoms in the CAARS, Mr. A's ADHD symptoms were at the clinical level of psychiatry (Table 1). In addition, according to the CAARS-O completed by his younger sister, the percentile of the subscale D. Problems with Self Concept was 99, indicating low self-esteem related to ADHD symptoms. His developmental and life history was obtained and evaluated with the CAARS using the Diagnostic Interview for Adult ADHD. The results indicated inattention: poor listening to others since childhood; avoiding tasks requiring sustained mental effort, poor logical thinking; easily distracted by ambient noise; forgetful in daily activities. Accordingly, he was diagnosed with ADHD, predominantly inattentive type in the DSM-5 (day 26).
During each examination, the pain numerical rating scale (NRS), the Hospital Anxiety and Depression Scale (HADS), and Pain Catastrophizing Scale (PCS) were administered. Subjective pain intensity was assessed using the numerical rating scale (NRS). Regarding the changes in NRS scores, the minimum clinically important difference is called MCID, decreases of-2 points (or-33.0%) or more in NRS is considered to be substantial or optimal. The average pain NRS score of Mr. A was high (7 points).
Symptoms of anxiety and depression were assessed using the Hospital Anxiety and Depression Scale (HADS). Based on previous studies, the MCID of HADS is set at 1.5. Mr. A's HADS results revealed clinical anxiety and depression symptoms (HADS-A, 15 points; HADS-D, 12 points).
Catastrophic thinking related to pain was evaluated using the Pain Catastrophizing Scale (PCS). It has been reported that strong catastrophizing thoughts leads to increased pain and disability possibility, resulting in chronic pain. The MCID of PCS can be improved by 38-44%. Mr. A's PCS results (PCS score 30 points) indicated clinically catastrophic thinking. Changes in pain NRS, HADS, and PCS during treatment course are shown in Figure 2.
Mr. A exhibited strong anger and suspicion at the periodontist who performed scaling. Dr. SK identified the uncontrollable temper outbursts and aggression as ASD irritability and prescribed risperidone (1 mg/day) (day 39). In addition, atomoxetine was initiated at 10 mg to treat severe anxiety and fear due to hyperarousal of ADHD that may contribute to irritability. At the subsequent examination (day 69), the patient responded to medication and stated that "pain was reduced." Temper outbursts and frequent suspicions and complaints of scaling in the primary referral hospital were reduced and Mr A was more polite and considerate. To prevent discontinuation of medication due to side effects, atomoxetine was carefully increased to 20 mg.
During the examination 2 weeks later (day 83), he was calmer, and his facial expression was less grim, and the amount complaints regarding the symptoms he faced had reduced. Therefore, atomoxetine was increased to 30 mg. During the examination 2 weeks later (day 97) he did not mention anger or suspicion of previous treatments except one mention of oral discomfort. He requested consultation on more practical topics such as the preparation of the document for sickness and injury allowance. Therefore, atomoxetine was increased to 40 mg. During the examination 2 weeks later (day 110), pain and numbness were almost resolved. He stated, "Lately, I have been very stable mentally." Additionally, he wanted to discuss with his boss when he would return to work, so the doctor created a medical certificate permitting him to return to work. Thereafter, atomoxetine was increased by 10 mg at ~2-week intervals, leading to reduced pain and numbness and improved mental health status. He returned to work after the administration of the maximum dose of atomoxetine (120 mg/day) (day 226) with no side effects indicating discontinuation. He stated, "I am able to set up my work better than before because of the medication I have been taking." Re-administration of the CAARS-S at day 324 showed the following percentiles for the subscale of the CAARS-S and improved ADHD symptoms: E. DSM-IV Inattentive Symptoms, 60; F. DSM-IV Hyperactive Impulsive Symptoms, 21; G. DSM-IV ADHD Symptoms Total, 36; and H. ADHD Index, 26 (Table 1). Pain NRS (4 points) improved by 3 points, HADS-A (7 points) improved by 8 points, HADS-D (8 points) improved by 4 points, and PCS (16 points) improved by 14 points (46.7%) from the first visit. Clinically significant improvement was observed exceeding MCID on all scales. Thereafter, he continued to visit the clinic once a month to receive medication. Regardless of the presence of mild pain, he continued his work and achieved social integration. He stated that "the pain has improved, and I am now able to do my hobby of reading, which I had to interrupt because of the pain."