Investigational applications of transcranial magnetic stimulation (TMS) in Mood Disorders: Studies from a tertiary care center in India.

The investigational potential of TMS in psychiatry is largely underutilized. In the current article, we present the results of five studies with similar TMS protocols that looked at the investigative applications of TMS via measuring cortical reactivity as potential biomarkers in mood disorders. The first two studies, evaluate potential of TMS parameters and Motor neuron system (MNS) as state or trait markers of BD. Third and fourth studies evaluate these as endophenotypic markers of BD. The fifth study which is an RCT evaluating add-on yoga in UD, evaluates if markers of CI can index the therapeutic response of yoga. In study one MT1 was significantly greater in the SM (symptomatic-mania) group compared to HC (healthy-control) (P=0.032). The cortical inhibition measures SICI was reduced in SM(P=0.021) and BD (remitted Bipolar) (P=0.023) groups compared to HC. LICI was increased in the SM(0.021) and BD(P=0.06) groups compared to HC. In study two, a significant group x time interaction effect was observed indicating higher putative MNS-activity mediation in patients compared to HC on SlCl(P=0.024), LlCl(P=0.033). There were no significant group differences noted in the endophenotype studies. The fifth study showed a significant time X group interaction for CSP, favoring improvement in YG (yoga-group) (p<0.01).No significant change was observed for LICI(p=0.2), SICI(p=0.5). Limitations of these studies notwithstanding, we conclude that cortical reactivity measured using TMS is a potential biomarker across the course of mood disorders, starting from state and trait markers to understanding the therapeutic mechanism of a particular treatment modality in these disorders.

A transdiagnostic evaluation of cortical inhibition in severe mental disorders using Transcranial Magnetic Stimulation.

Multiple lines of investigations suggest the presence of cortical inhibition aberrations as central to the phenotypic manifestations of severe mental disorders. Transcranial Magnetic Stimulation (TMS) combined with electromyography can characterize these inhibitory processes in the motor cortex with satisfactory temporal precision. We examined TMS-evoked short- (SICI) and long-interval intracortical inhibition (LICI) and cortical silent period (CSP) as markers of GABAA- (SICI) and GABAB-mediated (LICI and CSP) cortical neurotransmission in symptomatic individuals with mania (n = 40), schizophrenia (n = 76), unipolar depression (n = 86), and OCD (n = 43), and compared them against similar recordings in healthy subjects (n = 125). We hypothesized transdiagnostic GABAA deficits across all the clinical groups and diagnosis-specific GABAB alterations in mania (increased) and OCD (decreased). After controlling for potential confounder variables (gender, education, benzodiazepine prescription, and motor threshold) using the ANCOVA, we observed no significant group difference in SICI (F = 1.04, P = 0.38), but a significant group effect in LICI (F = 16.29, P < 0.001) and CSP (F = 3.02, P = 0.018). Post-hoc analyses revealed that LICI was significantly reduced in OCD but increased in mania and schizophrenia with reference to the healthy group. Similarly, CSP was significantly reduced in OCD and depression groups as compared to the reference group. We observed that LICI and CSP, both followed similar descending gradients from mania through schizophrenia and depression to OCD; with significant elevation in mania, and reduction in depression and OCD, as compared to the healthy group. This pattern of GABAB-mediated cortical inhibition aberrations needs independent validation as potential state-markers of distinct clinical categories.

Sociodemographic, Legal, and Clinical Profiles of Female Forensic Inpatients in Karnataka: A Retrospective Study.

BACKGROUND: Forensic patients are often admitted to psychiatric hospitals without any details of illness or treatment. They pose a unique challenge for clinical services in the context of diagnosis, management, and particularly legal issues. MATERIALS AND METHODS: We conducted a retrospective chart review using a structured data-extraction tool. A total of 23 female forensic inpatients were admitted under the Department of Psychiatry from January 2006 to June 2016. Data were analyzed by descriptive statistics. RESULTS: The mean age of the patients was 31.3 ± 7.9 years. In total, 82.6% of them were married, 87% were from a nuclear family, and 78.3% were from an urban background. Totally, 73.9% were referred from prison and 26.1% from the court. However, 73.9% were referred for the purpose of diagnosis and treatment and 21.7% for assessment of fitness to stand trial. Moreover, 47.8% had an alleged charge of murder (of killing close family members). A total of 30.4% had schizophrenia and other psychotic disorders, and 47.8% had a mood disorder. The mean duration of inpatient care was 6.2 ± 7.4 weeks, and 87% had shown considerable clinical improvement at the time of discharge. CONCLUSIONS: The majority of female forensic patients were young adults from nuclear families. They had mood disorders, schizophrenia, and other psychotic disorders. They were referred primarily for treatment purposes. Prospective studies are required for a better characterization of the relationship between crime and psychiatric disorders.

Cortical inhibition in symptomatic and remitted mania compared to healthy subjects: A cross-sectional study.

OBJECTIVES: Transcranial magnetic stimulation (TMS)-derived cortical reactivity studies provide a unique opportunity to non-invasively study gamma amino butyric acid (GABA)-mediated inhibitory neurotransmission in bipolar disorder (BD). Earlier studies were conducted in smaller samples and on patients who were on medications that can potentially confound the results. We aimed to study short-interval (SICI) and long-interval intracortical inhibition (LICI) in medication-naïve/free symptomatic (manic) BD patients (n=39), first episode mania (FEM) patients who had recently (≤6 months) remitted with treatment (remitted FEM; n = 28) and healthy subjects (HSs; n = 45). METHODS: Resting motor threshold (RMT), stimulation intensity to elicit a 1-mV motor evoked potential (MEP) (SI1 mV ), SICI and LICI were measured in three groups using single- and paired-pulse TMS. RESULTS: Motor thresholds were higher in the manic BD and HS groups compared to the remitted FEM group (P < .001). SICI was lower (P = .026) but LICI was higher (P = .044) in the manic BD and remitted FEM groups compared to the HS group. CONCLUSIONS: Lower motor thresholds in remitted FEM perhaps reflect the effect of treatment, and could be studied as potential prognostic neuromarkers. Inverse findings for SICI (reduced) and LICI (increased) in BD indicate a possible differential involvement of the GABAA and GABAB subreceptor systems. These could be trait markers as they are impaired in both mania and euthymia.