Discussion

This cross-sectional exploratory study assessed the prevalence and correlates of alcohol drinking and its impact on clinical outcome in patients with schizophrenia. The 12-month prevalence rates of alcohol consumption, hazardous drinking and alcohol dependence were 16.8%, 5.7% and 2.5% respectively. This is lower than the prevalence of hazardous drinking in a primary care setting in Goa (8.2%) ^{Reference D'Costa, Nazareth, Naik, Vaidya, Levy and Patel47} and in people with psychotic disorder from São Paulo, Brazil (7.3%). ^{Reference Menezes and Ratto14} Furthermore, the rates are much lower than the rates of alcohol use disorder in the USA (33.7%) ^{Reference Regier, Farmer, Rae, Locke, Keith and Judd2} and the UK (32%). ^{Reference Menezes, Johnson, Thornicroft, Marshall, Prosser and Bebbington9} This further emphasises that the cultural and regional differences in alcohol use patterns that are prevalent in the community extend to clinical samples of people with severe mental illness. Researchers have argued that the prevalence of substance misuse in severe mental illness is associated with the use and availability of that particular substance in the general population; ^{Reference Menezes, Johnson, Thornicroft, Marshall, Prosser and Bebbington9} the low prevalence of alcohol use disorder in our sample is probably a reflection of the low prevalence of alcohol use disorder in the general population in India (current alcohol use 6%, ^{Reference Ray, Mondal, Gupta, Chatterjee and Bajaj48} alcohol dependence 0.7% ^{Reference Reddy and Chandrashekar49} ).

In our study, males were more likely than females to use alcohol, a finding that has been demonstrated in the general population in Goa ^{Reference D'Costa, Nazareth, Naik, Vaidya, Levy and Patel47} and in people with mental health problems globally. ^{Reference Margolese, Negrete, Tempier and Gill23,Reference Mueser, Yarnold, Rosenberg, Swett, Miles and Hill50} Being unmarried or post-marital was significantly associated with drinking alcohol in our study. This is consistent with similar findings in other community ^{Reference Hall, Teesson, Lynskey and Degenhardt51} and clinic ^{Reference Fowler, Can, Carter and Lewin13} studies. This probably points to the critical role of family and social pressures in substance misuse behaviour. Ongoing family support is known to be associated with substantial reductions in adverse outcomes of substance use. ^{Reference Fischer, McSweeney, Pyne, Williams, Naylor and Blow52} Contrary to earlier reports from high-income countries, ^{Reference Mueser, Yarnold, Levinson, Singh, Bellack and Kee1,Reference Drake and Wallach21,Reference Hall, Teesson, Lynskey and Degenhardt51} in our study people who were economically active and had received formal education were more likely to be drinkers compared with those who were economically inactive and illiterate. A similar association between employment and drinking has been shown in men attending private primary care clinics in Goa, ^{Reference D'Costa, Nazareth, Naik, Vaidya, Levy and Patel47} where men who consumed any alcohol were more likely than abstainers to be employed. In another in-patient-based course and outcome study of substance misuse comorbidity in schizophrenia from India, it was reported that people misusing substances were more likely to be employed compared with those not using any substance. ^{Reference Aich, Sinha, Khess and Singh53} A possible explanation for this could be that in the absence of social security and pension schemes for chronically ill people in India, unlike in many high-income countries, only people with financial resources may be able to procure alcohol in India.

We did not find any significant association between drinking and clinical outcomes in schizophrenia, such as duration of illness, medication dosage or mental health service use. This may possibly be because the drinkers in our study were using alcohol at a less abusive level than the drinkers reported in other studies, especially from the USA. Some of our findings are supported by an Australian study that, despite having a high prevalence of substance misuse, could not demonstrate that substance misuse adversely affects the course of schizophrenia in terms of hospital admissions, suicide attempts or doses of antipsychotic drugs. ^{Reference Fowler, Can, Carter and Lewin13} Nevertheless, there is published evidence that heavy alcohol use is associated with adverse outcomes. In a study of community-dwelling people with chronic mental illness in Massachusetts, USA, ^{Reference Drake and Wallach21} people who misused substances were less able to manage their lives in the community compared with those who were not misusing any substance in terms of maintaining regular meals, adequate finances, stable housing and regular activities. They also showed greater hostility, suicidality and speech disorganisation, had poorer medication adherence and had increased rehospitalisation. A major finding in our study is that drinkers had significantly lower mean BPRS scores compared with non-drinkers. They had significantly low scores on all items that are considered negative symptoms of schizophrenia, namely blunted affect emotional withdrawal and motor retardation. There were also significantly low scores on the tension, uncooperativeness, somatic concerns, conceptual disorganisation and hallucination BPRS items. This may be at odds with earlier reports, ^{Reference Swofford, Scheller-Gilkey, Miller, Woolwine and Mance16,Reference Inderbitzin, Scheller-Gilkey and Lewine17} but some studies have shown low BPRS scores in people with dual diagnosis compared with people with a single diagnosis. ^{Reference Blow, Barry, Bootsmiller, Copeland, McCormick and Visnic54} There is evidence for different patient profiles in dual diagnosis. Some patients have higher symptom levels and poor social skills, but other patients have lower symptom levels, especially negative symptoms, and better social skills compared with people with schizophrenia who do not misuse substances. ^{Reference Arndt, Tyrrell, Flaum and Andreasen55-Reference Salyers and Mueser57} Predominance of negative symptoms in people with schizophrenia who do not misuse substances has been reported from studies in India ^{Reference Aich, Sinha, Khess and Singh53} and other LAMI settings. ^{Reference Menezes and Ratto14} There are also supporters of the self-medication theory, which suggests that by misusing psychoactive substances, people with schizophrenia relieve their negative symptoms. ^{Reference Potvin, Sepehry and Stip58}

From our study, the profile of a person with schizophrenia who drinks alcohol is a single or post-marital male who is economically active, has received formal education, has a lower symptom burden, especially of negative symptoms, and has adverse illness outcomes compared with patients who abstain from drinking. In our opinion, the lower symptom scores on the BPRS and the absence of adverse outcomes in drinkers is not an outcome of drinking behaviour. Cultural context in the use of alcohol may have a role to play. In high-income countries, deinstitutionalisation is considered to have put patients at risk of misusing substances. ^{Reference Menezes, Johnson, Thornicroft, Marshall, Prosser and Bebbington9} In the Indian setting, patients are more often under supervision of their families. Although alcohol is freely available, especially in Goa, drinking is not as ubiquitous in India as in high-income countries. Only patients with fewer deficit symptoms and with financial resources would be able to procure alcohol for consumption. It has been suggested that patients with more severe negative symptoms and premorbid functioning characterised by social isolation may lack the exposure to illicit substances or the social skills necessary to obtain them regularly to develop a drug use disorder. ^{Reference Cohen and Klein59} We can effectively conclude, therefore, that drinking alcohol is a result of better clinical outcomes and consequent better social functioning rather than the other way round.

Although people with schizophrenia who drank alcohol fared better symptomatically than abstainers, the subanalysis of drinkers showed a trend for worse outcomes with rising levels of drinking. Hazardous drinkers in our study had a longer illness duration, had more and longer in-patient admissions, needed more and higher doses of medication, and had higher BPRS scores. The drinking profile also worsens in hazardous drinkers, with hazardous drinkers exclusively drinking spirits and country liquor with a high alcohol content. Hazardous drinking is also more likely to occur in bars, and there are higher reports of morning drinking. These findings are in keeping with earlier studies on hazardous drinking. ^{Reference Gaunekar, Patel and Rane41}

The main limitations of our study relate to the cross-sectional design, which does not allow us to determine the direction of causality of the detected associations. Furthermore, our sample is relatively small, in keeping with the exploratory nature of our study. Finally, the lack of a validated vernacular version of an instrument such as the Structured Clinical Interview for DSM Disorders means that we had to rely on clinical diagnosis to identify people with schizophrenia. Our findings do show certain trends that are different from those seen in studies conducted in high-income countries. This strengthens the case for conducting a more comprehensive study, with a larger sample size, exploring the long-term course and outcomes of people with schizophrenia and comorbid alcohol use in India and other LAMI countries. As our sample was derived from a tertiary care mental health service, there is a potential for selection bias leading to overestimation of prevalence rates, as is common in specialist clinic-based studies. Since Goa is a small state, with the tertiary care hospital being easily accessible to the whole population, however, it is possible that our findings will be a true reflection of alcohol use in a community sample of people with psychotic disorders. The reliability of responses given in interviews to sensitive questions about one's alcohol use is uncertain. The data in our study were built on standardised assessment instruments such as the AUDIT and BPRS, which have established reliability allowing direct comparisons with other studies. Finally, because of the stigma attached to mental health problems, there is the possibility of underreporting of use of mental health services by the participants. There could also have been underreporting of alcohol consumption, especially since the data collectors were also involved in the clinical care of some of the participants. Alternative methods for independent verification of self-reports of such sensitive behaviours would not have been cost-effective, feasible or ethical, however. The alternative of using a self-administered questionnaire would have come with the attendant disadvantage of poor response rates.