Repetition-Dependent Adaptation and Prediction Error Signalling in Schizophrenia Patients With Auditory Hallucinations: A Roving Mismatch Negativity Study.

BACKGROUND: Dysregulated prediction error-signalling may explain auditory hallucinations in schizophrenia (SZ-AH). Roving mismatch negativity (rMMN) is an event-related potential (ERP) index where the deviant tone becomes the new standard with repetitions. Longer repetitions of standard stimuli yield a more positive sensory-adaptation response (Repetition Positivity-RP), elicit a stronger deviance-detection when interrupted (deviant negativity-DN), and the difference waveform between them reflects the strength of prediction-error signalling (mismatch negativity-MMN). METHODS: Twenty-three SZ-AH patients and twenty-three healthy controls (HC) underwent rMMN assessment. Various standard stimuli were repeated in sets of 3, 8 and 33 yielding three components for RP (RP3, RP8, RP33), DN (DN3, DN8, DN33), and MMN (MMN3, MMN8, MMN33). Amplitudes and latencies were compared across groups. Correlation between (a) rMMN amplitudes and latencies, and clinical variables in SZ-AH, and (b) the RP-DN amplitude pair for all three repetition sets (3, 8, 33) were also examined. RESULTS: All DN and MMN33 amplitudes were significantly suppressed in SZ-AH, while RP amplitudes were not. MMN33 latency was significantly longer in SZ-AH than HC. A few amplitudes and latencies significantly correlated with the frequency of AH. HC showed a significant positive correlation between RP-DN amplitude pairs for sets of 3 and 8 but not for 33; SZ-AH group's correlation profile was opposite to this. DISCUSSION: The link between repetition-dependent sensory-adaptation and deviance-detection is perturbed in SZ-AH. The unimpaired RP profile in SZ-AH is due to potential interference of AH with auditory information processing, and does not indicate a preserved short-term plasticity of the echoic memory trace.

A Primer on Interoception and its Importance in Psychiatry.

Interoception is the perception of signals from inside the body. It plays a significant role in the nervous, cardiovascular, respiratory, gastrointestinal, genitourinary, and endocrine systems. It is also closely related to the autonomic nervous system and inflammatory pathways and plays a significant role in our optimal functioning. Recently, interoception has gained more attention in neuropsychiatric research. Anatomical and physiological aspects of interoception like relevant brain areas, the role of the vagus nerve, and the autonomic nervous system are gradually being understood. Different facets of interoception like interoceptive attention, detection, magnitude, discrimination, accuracy, awareness, and appraisal have been proposed and their assessments and importance are being evaluated. Further, interoception is often dysregulated or abnormal in psychiatric disorders. It has been implicated in the psychopathology, etiopathogenesis, clinical features and treatment of mood, anxiety, psychotic, personality and addiction-related disorders. This narrative review attempts to provide a nuanced understanding of the pathway(s), components, functions, assessments, and problems of interoception and will help us to detect its disturbances and evaluate its impact on psychiatric disorders, leading to a better perspective and management. This will also advance interoception-related research.

Pheniramine dependence in obsessive-compulsive disorder: A case report.

BACKGROUND: Pheniramine abuse is reported not only in patients with psychiatric disorders but also in the general population. CASE REPORT: We report a case of pheniramine dependence in a patient with obsessive-compulsive disorder. The patient took about 250 mg orally daily and injected about 90 mg every week from the last six months. It reduced his anxiety, was cheaper than his other psychiatric medications, and free of stigma. He had lethargy, headache, uneasiness, anxiety, and poor sleep as withdrawal symptoms. RESULTS: This case highlights the vulnerability of those with psychiatric disorders towards pheniramine abuse. Hence, this report advocates the strict evaluation of over-the-counter drugs for patients with pre-existing psychiatric disorders.

Concurrent conventional & high-definition transcranial direct current stimulation for treatment of schizophrenia with co-morbid obsessive-compulsive disorder: A case report.

Non-invasive brain stimulation techniques such as conventional transcranial direct current stimulation (tDCS) and high definition tDCS (HD-tDCS) are increasingly being used as add-on treatment options in schizophrenia and obsessive-compulsive disorder (OCD). This is reporting of the use of a novel accelerated, symptom-specific, add-on tDCS (combining conventional and high definition) protocol in a patient with both schizophrenia and OCD. The intervention showed clinical utility by reducing both schizophrenia and OCD symptoms.

Risk mitigation with the use of clozapine - Quo vadimus.

The risk of neutropenia decreases significantly after the first year of clozapine initiation, and indefinite hematological monitoring is increasingly questioned. Despite comparable risks of neutropenia, the guidelines for antithyroid drugs - carbimazole and propylthiouracil do not recommend routine hematological monitoring. Assuming a similar pathogenic mechanism, data from antithyroid drugs indicate that neutropenia develops rapidly, and indefinite hematological monitoring misses a large majority of cases in the pre-symptomatic phase. Hence, a more pragmatic strategy of intensive hematological monitoring in the first year of clozapine initiation followed by selective haematological monitoring in case of febrile illnesses or pharyngitis needs to be explored.

Does lunar synodic cycle affect the rates of psychiatric hospitalizations and sentinel events?

The lunar synodic cycle is often believed to be associated with psychiatric emergencies and exacerbation in various countries, including India. However, the scientific literature regarding this matter is inconclusive. We aimed to evaluate the relationship between lunar cycle phase and admission rates plus occurrence of sentinel events in the psychiatric ward of a tertiary care general hospital in India. All admissions and transfer-ins (N = 780) to the Department of Psychiatry between August 1st, 2016 and July 31st, 2017 were evaluated from hospital records by a blinded author to obtain sentinel events, like requirement of physical restraint (PR) and chemical restraint (CR), occurring on full moon days (FM), new moon days (NM), and control days (CD). Statistical analysis was done by comparison of proportions. Significant positive differences were found when CR applied exclusively [p = .0008] on FM and NM days, and its frequency [p < .0001] in comparison to CD. Frequencies of parenteral [p = .0001] and per oral [p = .0064] modes of CR applied on FM and NM days showed significant positive results when compared with CD. Use of all restraints (PR plus CR) [p = .0017] and their frequencies [p < .0001] on FM and NM days were also positively significant. Sentinel events, such as use of restraints, especially chemical ones, in psychiatry in-patients are significantly more common during full moon and new moon phases.