Pharmacological modelling of dissociation and psychosis: an evaluation of the Clinician Administered Dissociative States Scale and Psychotomimetic States Inventory during nitrous oxide ('laughing gas')-induced anomalous states.

RATIONALE: A significant obstacle to an improved understanding of pathological dissociative and psychosis-like states is the lack of readily implemented pharmacological models of these experiences. Ketamine has dissociative and psychotomimetic effects but can be difficult to use outside of medical and clinical-research facilities. Alternatively, nitrous oxide (N2O) - like ketamine, a dissociative anaesthetic and NMDAR antagonist - has numerous properties that make it an attractive alternative for modelling dissociation and psychosis. However, development and testing of such pharmacological models relies on well-characterized measurement instruments. OBJECTIVES: To examine the factor structures of the Clinician Administered Dissociative States Scale (CADSS) and Psychotomimetic States Inventory (PSI) administered during N2O inhalation in healthy volunteers. METHODS: Secondary analyses of data pooled from three previous N2O studies with healthy volunteers. RESULTS: Effect sizes for N2O-induced dissociation and psychotomimesis were comparable to effects reported in experimental studies with sub-anaesthetic ketamine in healthy volunteers. Although, like ketamine, a three-factor representation of N2O-induced dissociation was confirmed, and a more parsimonious two-factor model might be more appropriate. Bayesian exploratory factor analysis suggested that N2O-induced psychosis-like symptoms were adequately represented by two negative and two positive symptom factors. Hierarchical cluster analysis indicated minimal item overlap between the CADSS and PSI. CONCLUSION: N2O and ketamine produce psychometrically similar dissociative states, although parallels in their psychosis-like effects remain to be determined. The CADSS and PSI tap largely non-overlapping experiences under N2O and we propose the use of both measures (or similar instruments) to comprehensively assess anomalous subjective states produced by dissociative NMDAR antagonists.

Causes of hospitalisation among a cohort of people with HIV from a London centre followed from 2011 to 2018.

BACKGROUND: We describe the spectrum of ICD-10 classified causes for hospitalisations occurring between 2011 and 2018 in a cohort of people living with HIV (PLHIV). METHODS: This sub-study includes 798 PLHIV participating in the Antiretroviral, Sexual Transmission Risk and Attitudes (ASTRA) questionnaire study who were recruited from a large London centre. A medical record review identified the occurrence and causes of hospitalisation from the date of questionnaire completion (February-December 2011) until 1 June 2018. Up to five causes were classified by an HIV clinician using the ICD-10 system. RESULTS: There were 274 hospitalisations in 153 people (rate = 5.8/100 person-years; 95% CI: 5.1, 6.5). Causes were wide-ranging; the most common were circulatory (16.8%), digestive (13.1%), respiratory (11.7%), infectious diseases (11.0%), injury/poisoning (10.6%), genitourinary diseases (9.9%) and neoplasms (9.1%). A tenth (27/274) of hospitalisations were related to at least one AIDS-defining illness. Median duration of hospitalisation was 5 days (IQR 2-9). At the time of hospitalisation, median CD4 count was high (510 cells/µl; IQR: 315-739), while median CD4 nadir was relatively low (113 cells/µl; IQR: 40-239). At admission, half of individuals (51%) had a previous AIDS-defining illness and 21% had viral load > 50 copies/ml. Individuals admitted for infectious diseases were particularly likely to have unfavourable HIV-related clinical characteristics (low CD4, viral non-suppression, not on antiretroviral therapy (ART), previous AIDS). CONCLUSIONS: In the modern combination antiretroviral therapy era, the spectrum of causes of hospitalisation in PLHIV in the UK is wide-ranging, highlighting the importance of holistic care for PLHIV, including prevention, early detection and treatment of comorbidities.

Prospective association of social circumstance, socioeconomic, lifestyle and mental health factors with subsequent hospitalisation over 6-7 year follow up in people living with HIV.

BACKGROUND: Predictors of hospitalisation in people with HIV (PLHIV) in the contemporary treatment era are not well understood. METHODS: This ASTRA sub-study used clinic data linkage and record review to determine occurrence of hospitalisations among 798 PLHIV from baseline questionnaire (February to December 2011) until 1 June 2018. Associations of baseline social circumstance, socioeconomic, lifestyle, mental health, demographic and clinical factors with repeated all-cause hospitalisation from longitudinal data were investigated using Prentice-Williams-Peterson models. Associations were also assessed in 461 individuals on antiretroviral therapy (ART) with viral load ≤50 copies/ml and CD4 count ≥500 cells/ µl. FINDINGS: Rate of hospitalisation was 5.8/100 person-years (95% CI: 5.1-6.5). Adjusted for age, demographic group and time with diagnosed HIV, the following social circumstance, socioeconomic, lifestyle and mental health factors predicted hospitalisation: no stable partner (adjusted hazard ratio (aHR)=1.59; 95% CI=1.16-2.20 vs living with partner); having children (aHR=1.50; 1.08-2.10); non-employment (aHR=1.56; 1.07-2.27 for unemployment; aHR=2.39; 1.70-3.37 for sick/disabled vs employed); rented housing (aHR=1.72; 1.26-2.37 vs homeowner); not enough money for basic needs (aHR=1.82; 1.19-2.78 vs enough); current smoking (aHR=1.39; 1.02-1.91 vs never); recent injection-drug use (aHR=2.11; 1.30-3.43); anxiety symptoms (aHRs=1.39; 1.01-1.91, 2.06; 1.43-2.95 for mild and moderate vs none/minimal); depressive symptoms (aHRs=1.67; 1.17-2.38, 1.91; 1.30-2.78 for moderate and severe vs none/minimal); treated/untreated depression (aHRs=1.65; 1.03-2.64 for treated depression only, 1.87; 1.39-2.52 for depressive symptoms only; 1.53; 1.05-2.24; for treated depression and depressive symptoms, versus neither). Associations were broadly similar in those with controlled HIV and high CD4. INTERPRETATION: Social circumstance, socioeconomic disadvantage, adverse lifestyle factors and poorer mental health are strong predictors of hospitalisation in PLHIV, highlighting the need for targeted interventions and care. FUNDING: British HIV Association (BHIVA) Research Award (2017); SMR funded by a PhD fellowship from the Royal Free Charity.

Recreational drug use and use of drugs associated with chemsex among HIV-negative and HIV-positive heterosexual men and women attending sexual health and HIV clinics in England.

BACKGROUND: There is little information on the prevalence of recreational drug use among UK heterosexual men and women, in particular on use of drugs associated with 'chemsex' within gay communities. The aim of this study was to examine among HIV-negative and HIV-positive heterosexual men and women in England: (i) the prevalence of recreational drug use (including use of drugs associated with chemsex), (ii) socio-economic/lifestyle correlates of drug use, and (iii) the association of drug use with sexual behavior measures and mental health symptoms. METHODS: Data are from the AURAH study of HIV-negative individuals attending sexual health clinics across England (2013-2014) and the ASTRA study of HIV-positive individuals attending HIV outpatient clinics in England (2011-2012). Prevalence of recreational drug use (past three months) and associations are presented separately among the four sample groups: HIV-negative (N = 470) and HIV-positive (N = 373) heterosexual men and HIV-negative (N = 676) and HIV-positive (N = 637) women. RESULTS: The age standardized prevalence of any drug use was 22.9%, 17.1%, 15.3%, and 7.1% in the four sample groups respectively. In all groups, cannabis was the drug most commonly used (range from 4.7% to 17.9%) followed by cocaine (1.6% to 8.5%). The prevalence of use of drugs associated with chemsex was very low among HIV-negative participants (1.0% heterosexual men, 0.2% women) and zero among HIV-positive men and women. In age-adjusted analysis, factors linked to drug use overall and/or to cannabis and cocaine use specifically in the four sample groups included Black/mixed Caribbean and white (vs. Black/mixed African) ethnicity, lower level of education , cigarette smoking, and higher risk alcohol consumption. Associations of recreational drug use with measures of condomless sex, depression, and anxiety were observed in the four groups, but were particularly strong/apparent among women. CONCLUSION: Providers need to be aware of cannabis and cocaine use and its potential link with sexual risk behavior and symptoms of depression and anxiety among heterosexual men and women attending sexual health and HIV clinics.

Multicenter European Prevalence Study of Neurocognitive Impairment and Associated Factors in HIV Positive Patients.

We conducted a cross-sectional study in 448 HIV positive patients attending five European outpatient clinics to determine prevalence of and factors associated with neurocognitive impairment (NCI) using computerized and pen-and-paper neuropsychological tests. NCI was defined as a normalized Z score ≤-1 in at least 2 out of 5 cognitive domains. Participants' mean age was 45.8 years; 84% male; 87% white; 56% university educated; median CD4 count 550 cells/mm3; 89% on antiretroviral therapy. 156 (35%) participants had NCI, among whom 26 (17%; 5.8% overall) reported a decline in activities of daily living. Prevalence of NCI was lower in those always able to afford basic needs (adjusted prevalence ratio [aPR] 0.71, 95% confidence interval [CI] 0.54-0.94) or with a university education (aPR 0.72, 95% CI 0.54-0.97) and higher in those with severe depressive symptoms (aPR 1.53, 95% CI 1.09-2.14) or a significant comorbid condition (aPR 1.40, 95% CI 1.03-1.90).

RESUMEN: Reportamos un estudio de tipo corte transversal que incluye 448 pacientes VIH seropositivos vistos en cinco clínicas especializadas en Europa con el objetivo de medir la prevalencia del trastorno neurocognitivo asociado al VIH (NCI por sus siglas en inglés) y los factores de riesgo asociados a éste. Se usaron pruebas neuropsicológicas computarizadas y en papel para determinar la presencia de NCI, definido como puntuación Z ≤ 1 en al menos 2 de los 5 dominios cognitivos evaluados. La media de edad de los pacientes fue 45,8 años, 84% eran hombres, 87% blancos y 56% tenían educación universitaria. La media de CD4 fue de 550 cel/mm3 y 89% de los pacientes recibían terapia antiretroviral. Un total de 156 (35%) participantes tenían NCI, de los cuales 26 (17%, 5,8% de la población de estudio) reportaron deterioro en actividades de la vida diaria. La prevalencia de NCI fue menor en participantes capaces de cubrir sus necesidades básicas (Razón de prevalencia ajustada [aPR] 0,71; Intervalo de confianza del 95% [95% CI] 0,54-0,94) o con educación universitaria (aPR 0,72; 95%CI 0,54-0,97) pero fue mayor en aquellos con síntomas de depresión severa (aPR 1,53; 95%CI 1,09-2,14) o alguna comorbilidad importante (aPR 1,40; 95%CI 1,03-1,90).

Minimal cognitive impairment in UK HIV-positive men who have sex with men: effect of case definitions and comparison with the general population and HIV-negative men.

BACKGROUND: To determine the prevalence of neurocognitive impairment (NCI) in UK HIV-positive and HIV-negative men who have sex with men (MSM). METHODS: HIV-positive and HIV-negative participants were recruited to a cross-sectional study from 2 London clinics and completed computer-assisted neuropsychological tests and questionnaires of depression, anxiety, and activities of daily living. Published definitions of HIV-associated neurocognitive disorders (HAND) and global deficit scores were used. Age- and education-adjusted neuropsychological test scores were directly compared with reference population data. RESULTS: A total of 248 HIV-positive and 45 HIV-negative MSM participated. In the HIV-positive group, median time since diagnosis was 9.4 years, median CD4 count was 550 cells per cubic millimeter, and 88% were on antiretroviral therapy. Prevalence of HAND was 21.0% in HIV-positive MSM (13.7% asymptomatic neurocognitive impairment, 6.5% mild neurocognitive disorder, and 0.8% HIV-associated dementia). Using a global deficit score threshold of 0.5, the prevalence of NCI was 31.5% (when averaged over 5 neuropsychological domains) and 40.3% (over 10 neuropsychological test scores). These results were not significantly different from the HIV-negative study sample. No consistent pattern of impairment was seen in HIV-positive patients relative to general male population data (n = 380). CONCLUSIONS: We found a prevalence of HAND and degree of impairment on neuropsychological testing of HIV-positive MSM that could represent a normal population distribution. These findings suggest that NCI may be overestimated in HIV-positive MSM, and that the attribution of NCI to HIV infection implied by the term HAND requires revision.

Recreational drug use, polydrug use, and sexual behaviour in HIV-diagnosed men who have sex with men in the UK: results from the cross-sectional ASTRA study.

BACKGROUND: Recreational drug use in men who have sex with men (MSM) is of concern because it might be linked to the transmission of HIV and other sexually transmitted infections. Evidence about drug use in HIV-diagnosed MSM in the UK is limited by representativeness of the study populations. We describe patterns of drug use and associations with sexual behaviours in HIV-diagnosed MSM in the UK. METHODS: We used data from the cross-sectional ASTRA study, which recruited participants aged 18 years or older with HIV from eight HIV outpatient clinics in the UK between Feb 1, 2011, and Dec 31, 2012. We examined data for MSM, assessing the prevalence of recreational drug use and polydrug use in the previous 3 months and associations with sociodemographic and HIV-related factors. We examined the association of polydrug use with measures of condomless sex in the previous 3 months and with other sexual behaviours. FINDINGS: Our analysis included data for 2248 MSM: 2136 (95%) were gay, 1973 (89%) were white, 1904 (85%) were on antiretroviral treatment (ART), and 1682 (76%) had a viral load of 50 copies per mL or lower. 1138 (51%) used recreational drugs in the previous 3 months; 608 (27%) used nitrites, 477 (21%) used cannabis, 460 (21%) used erectile dysfunction drugs, 453 (20%) used cocaine, 280 (13%) used ketamine, 258 (12%) used 3,4-methylenedioxy-N-methylamphetamine (MDMA), 221 (10%) used gamma-hydroxybutyrate or gamma-butyrolactone, 175 (8%) used methamphetamine, and 162 (7%) used mephedrone. In the 1138 individuals who used drugs, 529 (47%) used three or more drugs and 241 (21%) used five or more. Prevalence of injection drug use was 3% (n = 68). Drug use was independently associated with younger age (p < 0·0001), not being religious (p = 0·001), having an HIV-positive stable partner (p = 0·0008), HIV-serostatus disclosure (p = 0·009), smoking (p < 0·0001), evidence of harmful alcohol drinking (p = 0·0001), and ART non-adherence (p < 0·0001). Increasing polydrug use was associated with increasing prevalence of condomless sex (prevalence range from no drug use to use of five or more drugs was 24% to 78%), condomless sex with HIV-seroconcordant partners (17% to 69%), condomless sex with HIV-serodiscordant partners (10% to 25%), and higher-HIV-risk condomless sex after taking viral load into account (4% to 16%; p ≤ 0·005 for all). Associations were similar after adjustment for sociodemographic and HIV-related factors. Methamphetamine was more strongly associated with higher-HIV-risk condomless sex than were other commonly used drugs. INTERPRETATION: Polydrug use is prevalent in HIV-diagnosed MSM and is strongly associated with condomless sex. Specialist support services for MSM with HIV who use recreational drugs might be beneficial in the reduction of harm and prevention of ongoing transmission of HIV and other sexually transmitted infections. FUNDING: National Institute for Health Research.