Abstract
Substance misuse and mental health disorders are strongly associated [1]. This is both because psychoactive substances can induce a variety of psychiatric symptoms and syndromes, and because of an increased vulnerability of people with mental disorders to substance misuse [2]. The term ‘dual diagnosis’ is used in this specific sense throughout this paper, although it is recognised that comorbidity of substance misuse and mental disorders only represents one type of dual diagnosis problem.
In people with substance use problems, the most commonly encountered Axis I disorders are anxiety or affective disorders [3],[4], reflecting their high incidence in the general population. In the US Epidemiologic Catchment Area Study [3], 24%% of people with substance abuse or dependence also had a lifetime diagnosis of anxiety disorder (OR = 1.7), and 32%% had an affective disorder at some time in their lives (OR = 2.6). However, these were not the disorders with the highest levels of comorbidity. Antisocial personality disorder had the strongest association: 84%% of people with this diagnosis had a substance use disorder at some time (OR = 29.6). The highest comorbidities in the Axis I group were for bipolar I disorder, 61%% of this group also had substance-related problems (OR = 7.9), and for schizophrenia, where the rate was 47%% (OR = 4.6).
Since a high proportion of those treated by public mental health services have a psychotic disorder, comorbidity in this group has special significance. In a recent Australian sample of outpatients with schizophrenia, the lifetime prevalence of substance abuse or dependence was as high as 60%% [5]. There is now substantial evidence that substance abuse in people with psychiatric disorders leads to poorer functional and symptomatic outcomes, and to higher treatment costs [6–8]. The functional deficits are particularly noticeable in psychotic disorders, where they can occur at relatively low levels of intake or dependence [9]. Substance use in psychosis can lead to housing instability, poorer self-care, concurrent medical disorders, antisocial relationships and disrupted motivation [6]. Higher rates of violence, suicide and other high-risk behaviour [10] among people with substance abuse and psychosis have also been documented. Furthermore, episodes of decompensation may be precipitated by substance misuse, while certain drugs such as cannabis and amphetamines may induce a psychosis in the absence of an underlying psychiatric disorder.
Similar problems are seen with the non-psychotic disorders. Substance abuse may lead to anxiety and depression and these are also exacerbated by intoxication by or withdrawal from several substances [11–13] and in some cases, substantial recovery can be obtained after a period of abstinence from substance use [12]. Similarly, outcomes of personality disorder treatment are affected by the presence of substance abuse [14], and adverse outcomes from drug use tend to be associated with the severity of personality disorder features [15],[16].
The association between substance misuse and mental health disorders is therefore an important and complex one. Although a comorbid disorder may sometimes resolve during treatment of the primary condition, frequently the clinician is faced with the need to manage the two conditions simultaneously. Despite the importance of the issue, the treatment of comorbid substance misuse and mental health problems has attracted very little research [6],[7],[17]. Current data suggest that integrated treatment is critical to effective management [17]. Changes in substance use can impact on psychiatric symptoms or interact with psychotropic medication, and changes in symptomatic status sometimes trigger abrupt changes in substance use [6–8]. The timing and nature of interventions also needs to change, depending on mental status and the effects of intoxication or withdrawal.
The need for coordinated treatment presents great challenges for health workers, and the available data suggest that treatment is often fragmented or inappropriate [8]. This is particularly the case when mental health and alcohol and drug services are functionally, administratively and geographically separated, as typically occurs both in Australia and overseas. Substance abuse is often missed by mental health staff [18], and clients with comorbid disorders are often excluded from programs that could have helped them [8]. A recent survey of 338 mental health staff in Sydney found that 82%% reported that dealing with dual diagnosis clients was moderately or very difficult [19]. However, that study did not identify specific service-related problems, focusing instead on perceived and actual knowledge in dealing with dual diagnosis. More specific Australian data on the specific challenges facing therapists was required.
In 1997, a Dual Diagnosis Consortium of health workers, support organisations and carers was established in south-east Queensland to examine current issues in the management of comorbidity and to recommend service initiatives. A series of focus groups identified areas that were thought to present problems for service delivery. In order to test whether these areas were seen as issues by the staff of governmental health services across the state, a survey was widely distributed to hospital units and community centres offering mental health or alcohol and drug services. The survey had three main aims: (i) to determine which client management or service delivery issues represented the greatest problems for staff; (ii) to examine whether a set of potential solutions to these problems was seen as practical; and (iii) to examine perceived differences in problem or solution ratings between the mental health and alcohol and drug sectors, and between respondents in regional areas and those in the Brisbane metropolitan area.
The survey encouraged respondents to consider comorbidity of substance abuse or dependence with any Axis I or Axis II disorder except for antisocial personality disorder and developmental disability. The last two conditions were excluded because of the different treatment challenges that they pose in comparison with other diagnoses.
Method
Participants
The survey population comprised all clinical staff who were appointed at Level 2 or higher on nursing or professional awards in community mental health centres, alcohol and drug services or inpatient psychiatric units. Coordinators for data collection at each site identified the number of questionnaires that would be required. This resulted in a distribution of 186 questionnaires to alcohol and drug services and 1081 to mental health services across Queensland. These estimates probably resulted in some double counting of staff who serviced more than one centre (e.g. visiting psychiatrists). An attempt was made to check on the accuracy of local staff estimates from other sources, but these were also found to have limitations, generally because they also included less senior staff and casual employees.
Survey instrument
Issues for management of dual diagnosis clients that were covered in the survey
A later segment of the survey instrument asked respondents to rate the practicability of 16 ideas for potential service improvement that had been derived by the Consortium and by its focus groups. Each of these items took the form: ‘Would it be practical…?’ (e.g. ‘to establish a dual diagnosis team in your district, using existing staff resources’). Participants rated the potential solutions from 0 (not at all practical) to 3 (very practical).
The questionnaire also asked respondents to report their professional training, years of experience and whether their primary client group was children, adolescents or adults. They estimated the percentage of dual diagnosis clients on their caseload and the proportions of these clients who were from indigenous and non-English-speaking backgrounds.
Procedure
Questionnaires were distributed by the site coordinators, and were collected by them in sealed envelopes to preserve the anonymity of the respondent. Respondents who preferred not to route their response through the site coordinator mailed their surveys directly to the Consortium. Surveys did not have individual identifiers, but respondents did report data that would identify their workplace (postcode of the service; mental health or alcohol/drug service; adult, adolescent or child specialty). They were assured that ratings of specific workplaces would not be identified in reports of the results. In order to maximise the response rate, site coordinators were asked to follow up any staff who had not returned the survey within 1 month of the distribution, and additional copies of the instrument were sent if required to replace lost surveys.
Data entry, checking and analysis
The questionnaire data were checked by hand and by inspection of outliers. Data on the rating of items by the sample as a whole were analysed without substitutions for missing data. On analyses of group effects, the average item score across all respondents was substituted for any missing data. This procedure provided a conservative estimate of group effects. Data were analysed using SPSS 9.0.1 (SPSS Inc., Chigago, IL, USA). Results on individual variables were analysed using ANOVAs (or Chi-squared tests in the case of dichotomous data). Results across multiple variables utilised MANOVAs with a design of 2 (service sectors) X 2 (regions).
Results
Sample characteristics
Response rates
Five hundred and forty-four questionnaires were returned. Despite the use of assertive data collection methods, the estimated return rates from mental health services in two health districts in south-west Queensland were low (mental health, 16%%; alcohol/drug, 44%%). We therefore omitted responses from these districts (n = 52) from the analyses. This left a total of 112 surveys from alcohol and drug staff (79%% return rate) and 380 surveys from mental health services (42%% return rate). Across the reduced sample, 47%% of the distributed surveys were returned. In the Greater Brisbane area, 90%% of the alcohol and drug staff and 48%% of mental health staff completed the survey, whereas in regional Queensland the response rates were 63%% and 37%% respectively. Inspection of regional data from mental health services showed that the response rate from the western segment of the state (60%%) was higher than in northern coastal districts (32%%), allowing a comparison of responses from districts with higher versus lower return rates.
Professional mix and client focus
Seventy (32%%) of respondents from mental health services in Brisbane and 21 (12%%) of those from regional areas worked in specialist child and adolescent services. Only five respondents worked in specialist services for adolescents. For the purposes of analysis, responses were aggregated across adult services and, child and adolescent services. Every professional group participated in the survey. Nursing was the most prevalent profession in both service sectors, comprising 45%% of the overall sample. Medical staff formed 14%%, psychologists 17%%, and 22%% were from other allied health groups. In Brisbane, there was a significant difference between services in the professional mix of respondents (χ2 = 15.2, df = 3, p < 0.01), with alcohol and drug services having a higher proportion of nursing staff than mental health services. This was not seen in regional areas.
Staff experience
Fifty-eight per cent of the sample had over 10 years in professional practice, and only 22%% had less than 5 years of experience. In Brisbane there was a significant difference in experience between sectors (χ2 = 6.2, df = 2, p < 0.05), with more alcohol and drug workers than mental health staff in the most experienced category (67%% vs 53%%). This was not seen in regional areas.
Estimated client mix
Respondents from mental health services estimated that 21%% of their clients had comorbid substance misuse, compared with the estimate from staff of the alcohol and drug services that 33%% of clients had comorbid mental health disorders (F = 6.6, df = 1,437, p < 0.001). The estimated proportion of clients with comorbid disorders was also higher in regional areas than in Brisbane (F = 4.1, df = 1,437, p < 0.05). There was no interaction between sector and region.
The percentage of dual diagnosis clients from a non-English-speaking background was estimated to be 7%%, and the percentage from indigenous groups was 6%%. Rates of non-English-speaking clients did not significantly differ between services or regions. The rate of indigenous clients was judged to be highest in regional alcohol and drug services (20%%) and lowest in alcohol and drug services in Brisbane (2%%).
Issues for the management of clients with dual diagnosis
A primary focus of the survey was to identify management problems that had arisen in the previous year with dual diagnosis clients. Issues were considered to have produced a substantial difficulty if they were rated at or above the midpoint of the scale (which ranged from no difficulty to extreme difficulty). At least one issue was reported to have produced a substantial problem by 98%% of respondents, and on average almost half of the 45 problems were rated as substantial (mean = 21.1, SD = 9.7).
Issues rated as substantial by a majority of both service sectors or of neither sector
Table 2 also lists the issues that were not rated as substantial by a majority of staff from either service. It is noteworthy that all client management problems in the survey were rated as substantial by at least 25%% of the respondents. Resources for therapists on mental health problems and crisis intervention by mental health services were seen as presenting the least difficulty. Over half of the issues presenting a low level of difficulty involved the alcohol and drug services, which were seen as relatively responsive to requests for assessment, information and crisis intervention. Surprisingly, the geographical separation between centres was not seen as a problem by the majority of staff, despite the large distances between some Queensland centres.
Differences in problem ratings between professions, service sectors and regions
Analyses were conducted to examine whether the respondents' professional discipline should be included as an independent variable in the main analyses of problem and solution ratings. Professions were divided into nurses and other professions (resulting in a nearly even split). Neither the multivariate interactions nor the main effects were significant, and no individual issues were significant on univariate analysis (p < 0.001). Accordingly, profession was omitted from the analyses of group differences.
Issues on which there were differences between service sectors or regions
Six issues were rated as being substantially more problematic for mental health staff than for those from alcohol and drug services, but 17 were rated as posing a greater management problem by staff from alcohol and drug services. One difference between the sectors was moderated by an interaction between service sector and region: the availability of services for alcohol and drug problems was seen as a greater issue by mental health staff, but only in regional areas. Five issues posed more of a problem for staff in regional areas than in Brisbane. These primarily involved decreased access to specialist resources in regional areas. No issues posed a greater problem for staff from the Brisbane area.
Perceived solutions to problems
Numbers and proportions of respondents rating solutions as practical
Respondents from the alcohol and drug sector saw the full set of proposed solutions as significantly more practical than did staff from mental health services (F = 2.4, df = 16,423, p = 0.002). There was no significant main effect for region and no significant interaction. Alcohol and drug respondents gave higher practicality ratings than mental health staff to cross-sector services such as delivery of assessment, consultation, client management or treatment at the other service's centres (p < 0.001).
Discussion
The overall response rate in the study (47%%) was lower than we would have preferred, but was comparable to or greater than many other surveys of busy health practitioners [20–22]. The participation level of alcohol and drug staff in the survey (79%% overall) gives confidence that the results from these services are highly representative of that whole sector. The response rates in the mental health sector were lower, especially in regional north-east Queensland. Because of the problems eliminating double-counted staff and staff on leave from the estimates of available staff at each centre, all of the obtained response rates were likely to be underestimates. However, we remained concerned about the representativeness of ratings from mental health staff in regional areas. Given that the response rate from mental health staff in western districts (60%%) was higher than in the north-east (32%%), we checked whether the responses to the survey differed between these two zones. Each zone contained regional centres and very remote areas. Despite the large number of comparisons, only 1 of the 61 survey items showed a significant difference between zones (uncorrected p < 0.05). Exchanging client information between services was seen as more practical by staff in the northern zone. These results suggested that responses from mental health staff in areas with a lower response rate were substantially the same as those from areas with a higher response rate. This gives confidence that the overall results were not substantially biased by non-representativeness in some segments of the sample.
The size of the sample also means that large numbers of staff were endorsing specific items. All of the issues in Table 2 were rated as substantial problems by at least 200 health service staff, as were all of the solutions in Table 4. The top four problems and the top seven solutions were all rated above the midpoint by over 300 staff. This represents a potential impact on a substantial number of clients.
Both staff of mental health services and those of alcohol and drug services identified several issues as having posed substantial problems for their management of people with comorbid substance misuse and mental health problems in the previous year. The most difficult were generally not related to the direct clinical management of clients, but more to their aftercare and rehabilitation. They included their clients' finding appropriate work, their ability to identify and access rehabilitation programs, and the existence of limited availability of recreational activities that did not involve drug use. Another set of issues centred on accommodation and respite care, including rejection of clients from accommodation. Both sets of issues may be seen as a matter of additional resources, for example involving the provision of more accommodation or the establishment of ‘damp houses’ [23]. However, it is also possible that a more inclusive policy towards comorbid clients by existing services would help to alleviate many problems.
The issue of respite care was also linked to another theme in the results: the need for greater support for families. Other closely associated issues were a need for support groups and for relevant information and other resource materials. These issues were also strongly endorsed in parallel consultations with carers. These problems were even more pronounced in regional areas than in south-east Queensland, and innovative approaches including carer support groups connected by the Internet or teleconferences may be required.
Three specific gaps in services were identified: (i) a lack of dual diagnosis services for adolescents; (ii) a lack of alcohol and drug services after business hours; and (iii) a lack of specialist services for chronic dual diagnosis clients. All of these require additional targeted resources to fully rectify the problems, but a partial solution to these and many other problems may be found through cross-training of staff in the specialty of the complementary service. A need for cross-training and for other resource materials was identified by both services as a significant issue, and while several workshops and training places have already been offered to staff, there was clearly a need for training programs to be more widely available. Access to training in regional areas has been assisted by the use of video-conferencing links and regional workshops, but more extensive training in distance education mode is needed.
A prominent feature of the results was the report by respondents of insufficient collaboration between service sectors in managing dual diagnosis clients. This observation was of significant concern, given that integration of services for this population is the one well-established feature of an effective management approach [17]. The lack of integration included a lack of joint case conferences, significant problems obtaining assessments or inpatient treatment and problems obtaining information on the progress of clients from the complementary service. For more than half the sample, the problems extended to disputes over case management and transferring duty of care.
Understandably, both service sectors reported greater difficulty dealing with problems in the other sector's specialty area than in their own. However, alcohol and drug staff reported a greater range and intensity of difficulties dealing with mental health problems and accessing mental health services than mental health staff had with access to services in the alcohol and drug area. Alcohol and drug staff had a problem activating legal provisions. Focus groups indicated that a particular problem was obtaining involuntary treatment through the Mental Health Act for intoxicated clients who were currently suicidal or violent. Whether such patients were seen as mentally ill within the meaning of the Act appeared to depend on local policy and on the particular staff rostered for duty. Solution of this problem is likely to require that a clarification of the relevant legal provisions be communicated to admission staff, and that local solutions be developed to the significant management problems that are posed by these patients.
Part of the reason for the greater intersectoral problems reported by staff of the alcohol and drug service may have been that the majority of mental health problems which emerged in alcohol and drug treatment settings tended to be anxiety or depressive disorders. The frequency of these disorders is both because of their relative frequency across the community in comparison with psychosis [4], and because dysphoria is commonly associated with intoxication or withdrawal from a number of substances [11]. In recent years, anxiety and non-psychotic depression have frequently been seen as outside the priority areas for adult mental health services, either because they have not been sufficiently severe in intensity, or because the priority given to ‘serious mental disorders’ by mental health services has often been understood by alcohol and drug staff as excluding most of their clients from consideration. In either case, the broader interpretation of serious disorders in the Second National Mental Health Plan [24] may help to remedy this problem.
Another explanation may be that the staff of mental health services are more confident in dealing with dual diagnosis without cross-sectoral referral. If so, this greater confidence could be due to access to a greater number or range of consultants who are available within the service or to a higher average level or breadth of staff training. Alternatively, a broad-based case management model may have habituated mental health workers to dealing with a very wide range of client issues. The survey was not designed to test these hypotheses. If differences in training underpin the greater perceived difficulty by staff of alcohol and drug services, the provision of cross-training and consultation might particularly focus on the needs of these services. However, a greater perceived difficulty may not necessarily reflect a relative deficiency in knowledge or skills: higher levels of confidence can sometimes be misplaced [25].
Mental health staff respondents provided a relatively low estimate of the prevalence of the dual disorders (21%%). This was approximately the same as recent Australian data on an unselected sample of outpatients with schizophrenia, which suggested a current comorbidity rate of 27%% [5]. On the other hand, it was considerably below data obtained by the authors from a local study of inpatients with early psychosis, which found comorbidity in 65–70%% [26]. While the inpatient setting of the local study and the relatively young age of its participants may have inflated its estimate of comorbidity [6],[27], a tendency to under-report substance abuse in mental disorders would be consistent with other observations that dual diagnosis tends to be missed in mental health assessments [18],[28], partly because of inadequate screening procedures. We asked survey respondents whether it would be feasible to institute routine screening of clients for mental health and alcohol and drug problems at intake or assessment. Eighty-three per cent of respondents said that it would be feasible to do this, and our research team is currently conducting field trials of screening instruments to detect alcohol and drug use and mental health problems in this population.
Routine screening was only one of a raft of potential solutions that were considered feasible by the respondents. Staff reported that there were a number of ways that collaboration between the service sectors could be improved. Ideas that were favoured by respondents included free exchange of client information, joint case conferences, development of shared treatment plans and provision of consultation or supervision to each other. These ideas could broadly be grouped into the development of more effective intersectoral communication and processes to increase skills in the management of comorbidity. Respondents also said that local interagency networks to address dual diagnosis could be established, and that they could facilitate the formation of dual diagnosis support groups. Formation of specialist dual diagnosis teams failed to be rated as practical by a majority of respondents. However, that proposal was rated in terms of existing staff being used to provide the services. Even within that context, the idea was favoured by 45%% of respondents.
Both the problem areas and solutions that were identified by respondents need to be evaluated in the context of the current client mix within the surveyed services. It may be that a survey of general practitioners, for example, may highlight a different set of issues and solutions. The same might be said for a survey that focused on specific disorders, communities or ethnic groups. However, a theme through the results is one of commonality. While some differences between services and regions emerged, there was agreement about a central group of problems and solutions that appeared to have broad relevance to people with significant levels of comorbidity. Addressing the issues raised by this survey is likely to provide a solid basis for the development of targeted responses to specific problems.
The current survey appears to be the most comprehensive of its kind so far conducted in Australia. It suggests that there are significant challenges faced by services in dealing with people with comorbid substance use and mental health problems, but that many of these challenges can be addressed with greater collaboration of services and an allocation of greater priority to servicing this very needy population. Results of the survey have been communicated to service directors across Queensland, and several units are currently assessing aspects of its recommendations that they might implement. One aspect that is receiving strong support is the adoption of routine screening for dual diagnosis and the presentation of workshops and training programs on the topic.
The enthusiasm for potential solutions by the survey respondents and by health services is substantial cause for optimism. So are other developments that have been occurring contemporaneously, including the mention of comorbid substance abuse as an area of special need in the Second National Mental Health Plan [24], and the appointment of staff to develop dual diagnosis programs in three states. While there clearly is much more to be done, these developments bode well for the future. Comorbidity is clearly now on the agenda.
Footnotes
Acknowledgements
This work was in part supported by the Community Services Program of The Prince Charles Hospital and Health Service District. We thank Elizabeth Leitch, Suzanne Rimland, Maria Makowska and Ken Pullen for their contributions to the Working Party that designed the survey and arranged collection of the data, Linda Boyce for data entry, and Ross Young for comments on the survey and on the paper. We gratefully acknowledge the work of the 58 site coordinators for data collection, and the assistance of all staff who completed the surveys.