Understanding substance misuse amongst the mentally ill: an investigation of the context of, and motivations for, drug and alcohol use in an in-patient sample of individuals with psychotic illness

Background: Dual diagnosis (substance misuse and mental illness) is recognised as a significant clinical problem. However there is little evidence contributing to the understanding of what motivates people with psychotic illnesses to use drugs and alcohol, and in what social context. There is still less evidence concerning the correlates of dual diagnosis in in-patient settings including the relationship between mental health service settings and the initiation and maintenance of substance misuse. This study reports the prevalence, social context of, and motivations for substance use in a sample of in-patients with psychotic illnesses.;Methods and measures: Staff on 9 acute mental health wards and 2 psychiatric intensive care units in North London used a Clinician Drug and Alcohol Use Rating Scale to assess whether working age in-patients with psychotic illness also met the criteria for harmful alcohol or drug use, or dependence during the preceding six months. Those meeting the criteria for harmful use or dependence were then approached to participate in the study. Participants were interviewed and asked to report on the nature, extent, social context and attributions of their substance use, and whether they had continued to use whilst an in-patient. Measures used included an Inventory of Alcohol and Drug Use Situations, a Self-Medication Questionnaire, a demographic schedule and a structured set of questions concerning substance use history and it's relationship to mental health service settings.;Results: All working age adult in-patients (264) were screened for a current or recent substance use disorder. One hundred and twenty nine individuals met the study criteria (48.9%), whilst a further 39 (15%) had a substance use history, but no associated impairment of these, 102 agreed to take part in the study (response rate 79%). Those with dual diagnosis were younger on average and more likely to be male, than those with psychosis alone. The majority (76%) suffered from schizophrenia and were detained under the Mental Health Act (1983), with 19% being street homeless. A wide range of substances including opiates, stimulant substances and khat were used by participants, but alcohol, cannabis and cocaine (respectively) were the most frequently used substances. Eighty one percent of the participants reported using on the ward during their current admission, with almost half of the participants buying substances from other in-patients. Methods of using reflected the wide range of substance use reported, and included intravenous injection, chasing, and smoking. A third of participants reported feeling pressurised to buy, or use substances with other in-patients. For the majority substance use was clearly a social activity with three quarters of the participants reporting that they typically used or drank with others. Sixteen percent of the participants reported typically using with other mental health service users. Two principal components analyses of use situations and self medication data each revealed three factors, explaining 68% and 66% of the variance respectively. All factors had high mean scores, and elicited motivations for substance use. They were (use related to): negative personal and social states (48% variance), pleasant social conditions (13% variance), reward (7% variance), social interaction and boredom (41%) social acceptance (14% variance), and medication side effects (9% variance). An exploratory cluster analysis aimed at identifying sub-groups with distinctive patterns of motivations for use. Scores within clusters varied, with the membership of one cluster scoring highly on all factor items while other cluster members scored low on several items, clearly influencing their motivations for use. This exploratory analysis gives some indication that there are a number of distinctive patterns of use, including people who use in a wide range of situations with a variety of motivations, those who primarily use for relief of unpleasant feelings and social anxiety, and those whose use is predominantly social.;Conclusions: Substance misuse is a common problem in users of adult mental health services, and innovative solutions to understand and address these problems are needed. Although it was uncommon for individuals to directly medicate the symptoms of their illness with substances, their motivations for use reflected a range of social difficulties, isolation and other affective problems. Further investigation of demographic variables and substance use motivations in a larger sample may be an effective way of delineating sub groups with distinct motivations and of developing treatment strategies which take these motivations into account