Transcranial Alternating Current Stimulation (tACS) as a Tool to Modulate P300 Amplitude in Attention Deficit Hyperactivity Disorder (ADHD): Preliminary Findings.

Studies examining event-related potentials (ERP) in patients affected by attention deficit/hyperactivity disorder (ADHD) have found considerable evidence of reduced target P300 amplitude across different perceptual modalities. P300 amplitude has been related to attention-driven context comparison and resource allocation processes. Altered P300 amplitude in ADHD can be reasonably assumed to be related to ADHD typical cognitive performance deficits. Transcranial alternating current stimulation (tACS) can increase the amplitude of endogenous brain oscillations. Because ERP components can be viewed as event-related oscillations (EROs), with P300 translating into the delta (0-4 Hz) and theta (4-8 Hz) frequency range, an increase of delta and theta ERO amplitudes by tACS should result in an increase of P300 amplitudes in ADHD patients. In this pilot study, 18 adult ADHD patients (7 female) performed three consecutive blocks of a visual oddball task while the electroencephalogram (EEG) was recorded. Patients received either 20 min of tACS or sham stimulation at a stimulation intensity of 1 mA. Individual stimulation frequency was determined using a time-frequency decomposition of the P300. Our preliminary results demonstrate a significant increase in P300 amplitude in the stimulation group which was accompanied by a decrease in omission errors pre-to-post tACS. However, studies including larger sample sizes are advised.

A comparison of two psychiatric service approaches: findings from the Consultation vs. Liaison Psychiatry-Study.

BACKGROUND: Psychiatric comorbidities are common in somatically ill patients. There is a lack of data that can provide clear insights into substantial comparative advantages of different Consultation/Liaison Psychiatry (CLP) services. METHODS: The Consultation versus Liaison Psychiatry-Study collected and analyzed data of 890 primarily somatically ill hospital inpatients presenting with psychiatric symptoms in a prospective observational study design. One group was treated via a liaison-model (LM) with regular consultation hours, the other via an on-demand-model (ODM) with individually requested consultations. RESULTS: Five hundred forty-five LM and 345 ODM patients were compared. Patients in the LM were, on average, older compared to the patients of the ODM. The vast majority (90.8%) of individuals for whom a psychiatric consultation was requested came from internal medicine. The most common diagnoses were affective disorders (39.3%), organic mental disorders (18.9%), alcohol-induced mental disorders (11.3%) and reactions to severe stress/adjustment disorders (10.4%). Organic mental disorders were significantly more common in patients seen in the LM (24.0% vs. 10.3%, p < 0.001) while affective disorders were more frequently diagnosed in the ODM (46.6% vs. 34.8%, p = 0.001). Patients seen in the ODM were, on average, more severely affected compared to patients seen in the LM and required more extensive treatment. 16.3% of ODM patients were regarded as potentially suicidal; among these, 3.5% were acutely suicidal and 12.8% latently suicidal. Any form of further treatment was required by 93.0% of ODM patients compared to 77.8% in the LM. Pharmacological treatment with benzodiazepines, usually used as short-term treatment, was more frequently prescribed to patients seen in the ODM while patients seen in the LM were more often started on selective serotonin reuptake inhibitors, indicative of long-term treatment. CONCLUSIONS: Patients in need of less acute treatment were considerably less common in the ODM. The data indicate a possible risk of such patients to remain unrecognized. A quasi-liaison model is recommended to be the best suitable and cost-effective way of providing psychiatric care to somatically ill patients with psychiatric comorbidities.

Synthetic Cannabinoid Use in a Psychiatric Patient Population: A Pilot Study.

BACKGROUND: Consumption of natural cannabis (NC) and synthetic cannabinoids (SCs) has been associated with psychotic disorders. We compared the prevalence of use, consumer profiles, and psychosis-inducing potential of NC and SCs in a specific high-risk population. METHODS: This prospective pilot study included 332 patients (18-64 years, mean 36.83, SD 13.33). Patients' sociodemographics and medical histories as well as illicit substance use and psychiatric symptom histories were collected using a drug consumption survey that assessed the use of new psychoactive substances and the Psychotic Symptoms Interview. RESULTS: In total, 7.2% of all patients, 10.6% of psychotic patients, and 4.5% of nonpsychotic patients reported SC consumption. Compared with SCs, NC was consumed much more frequently by its users (mean 222.73, SD 498.27). NC and SC use induced persistent psychosis. Psychotic symptoms were first experienced by patients with a history of NC or SC use during intoxication and persisted after cessation (>1 year) of drug use. Positive and negative symptoms tended to be more severe in SC and NC users, respectively. CONCLUSIONS: NC and SCs may cause different symptom clusters. These relationships should be further evaluated.