Clinical profile of participants in a brief intervention program for cannabis use disorder

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1 Journal of Substance Abuse Treatment 20 (2001) 45± 52 Regular article Clinical profile of participants in a brief intervention program for cannabis use disorder Jan Copeland a, *, Wendy Swift a, Vaughan Rees b a National Drug and Alcohol Research Centre, University of New South Wales, Sydney 2052, Australia b University of Boston, Boston, MA, USA Received 18 February 2000; received in revised form 30 June 2000; accepted 20 August 2000 Abstract The increasing demand for cannabis dependence treatment has led to the identification of significant gaps in the knowledge of effective interventions. A randomized controlled trial of brief cognitive ±behavioral interventions (CBT) for cannabis dependence was undertaken to address this issue. A total of 229 participants were assessed and allocated to either a 6-session CBT program, a single-session brief intervention, or a delayed-treatment control group. This paper demonstrates that individuals with cannabis use disorder will present for a brief intervention program. While they report similar patterns of cannabis use to nontreatment samples, they report a range of serious health and psychosocial consequences. While they appear relatively socially stable, they typically demonstrated severe cannabis dependence and significantly elevated levels of psychological distress, with the most commonly cited reason for cannabis use being stress relief. There were clinically relevant gender differences among the sample. This study provides more evidence of the demand for, and nature of issues relevant to, interventions for cannabis use disorders, and supports the need for further research into how best to assist individuals with these disorders. D 2001 Elsevier Science Inc. All rights reserved. Keywords: Marijuana; Dependence; Treatment; Psychological co-morbidity; Gender 1. Introduction * Corresponding author. Tel.: ; fax: address: j.copeland@unsw.edu.au (J. Copeland). Population-based studies have consistently revealed that cannabis is the most widely used illicit substance in many Western countries, with one third to one half of adults having tried it (Australian Institute of Health and Welfare, 1999; Hall, Johnston, & Donnelly, 1999). While the existence of cannabis dependence has been a contentious issue for some years, there is now a growing body of evidence that suggests there is a cannabis dependence syndrome comprising symptoms consistent with drugs such as alcohol and the opiates (Anthony & Trinkoff, 1989; Kandel, Chen, Warner, Kessler, & Grant, 1997; Swift, Hall, Didcott, & Reilly, 1998). Despite this, there has been a paucity of clinical research into its assessment or treatment. Major epidemiological studies of the prevalence of mental disorders in the United States (e.g., Anthony, Warner, & Kessler, 1994; Robins & Regier, 1991), Australia (Hall, Teesson, Lynskey, & Degenhardt, 1998) and New Zealand (Wells, Bushnell, Hornblow, Joyce, & Oakley- Browne, 1989) reveal cannabis to be the most common illicit drug dependency among adults, with a lifetime prevalence in the range of 2±5%. Based on the epidemiological literature, Hall, Solowij, and Lemon (1994) estimated the risk of developing cannabis dependence among those who had ever tried it as approximately one in ten. This risk increases with frequency of cannabis use, so that among those who have used it more than a few times, the risk ranges from one in five to one in three. Recent research on a nontreatment sample of long-term Australian users found 92% met lifetime DSM-III-R criteria for cannabis dependence (Swift, Copeland, & Hall, 1998). While many people with a substance use disorder do not seek assistance from a health professional (Anthony & Helzer, 1991; Hall et al., 1998), recent data indicate substantial increases in the number of cannabis smokers seeking professional assistance to quit, or to manage cannabisrelated problems. The 1995 Australian census of clients of treatment service agencies found that there had been a 60% /01/$ ± see front matter D 2001 Elsevier Science Inc. All rights reserved. PII: S (00)

2 46 J. Copeland et al. / Journal of Substance Abuse Treatment 20 (2001) 45±52 increase in clients principally seeking help for cannabis problems, compared with the previous survey in 1992 (from 4.1% to 6.7%) (Torres, Mattik, Chen, & Baillie, 1995). Similar data are reported in the United States. The US Treatment Episode Data Set reported a doubling in admissions for primary cannabis problems from 1992 to 1996 (SAMHSA, 1999), with some groups reporting that cannabis accounts for 20±41% of primary drug of abuse among treatment admissions (NIDA, 1998). Despite the increased understanding of the potential for cannabis-related harms (Kalant, Corrigall, Hall, & Smart, 1999) and the growing demand for treatment there is little known about the characteristics and intervention needs of cannabis users seeking treatment. Stephens, Roffman, and Simpson (1993) reported that among 382 adults seeking treatment specifically for cannabis (76% male), the majority were not currently abusing other substances, although formal diagnostic criteria were not reported. The participants reported many negative consequences of their cannabis use, including an inability to stop using and numerous failed quit attempts, withdrawal symptoms, family members complaining, and financial difficulties. They also reported clinically significant levels of psychiatric distress. A later study by Budney, Radonovich, Higgins, and Wong (1998) compared 62 adults seeking treatment for cannabis dependence with 70 individuals seeking cocaine dependence treatment on sociodemographic characteristics, substance use history, psychosocial functioning, psychiatric symptoms, and health status. The majority of the cannabisdependent sample were male (87%), at least high schooleducated (83%), and employed full-time (58%). They reported cannabis-related problems similar to those described by Stephens and colleagues (1993) and were more ambivalent and less confident of stopping cannabis use than the cocaine group were of abstaining from cocaine (Budney et al., 1998). While there has been a range of therapies applied to the treatment of drug dependence, there has been very little systematic development of interventions designed for cannabis dependence. Two randomized trials of cognitive ± behavioral therapy (CBT) for cannabis dependence, the latter including a control group, have been performed recently in the United States (Stephens, Roffman, & Simpson, 1994, cited in Budney et al., 1997). These studies have compared CBT with a basic skills training approach, both of which were tailored specifically to meet the unique demands of cannabis-dependent clients. They offer a promising, empirically verifiable approach to the treatment of cannabis dependence, and clearly warrant further investigation. This paper reports on the clinical characteristics of a group of adults seeking treatment for cannabis use disorders in Sydney, Australia. The design of the study was an adaptation of the study by Stephens and colleagues (1994) to an Australian context, using a briefer, individualized CBT approach in a randomized controlled trial. 2. Materials and methods 2.1. Participants Participants were 229 adults recruited between November 1996 and June 1998 via advertisements in local newspapers and radio interviews that promoted a treatment research program for persons seeking assistance in abstaining from cannabis use. The recruitment efforts generated 1075 telephone calls which yielded 510 eligible and interested participants. The vast majority of ineligible calls were from parents concerned about their child's cannabis use or individuals enrolled in methadone maintenance. The majority of those who chose not to make an appointment were provided with a pamphlet on quitting cannabis. Of that group of 510, 285 made appointments to attend and 238 presented for assessment. Of the 238 that completed screening procedures, a further nine were excluded prior to randomization because they were classified as having scored more than the cutoff score for alcohol use disorder as described below Inclusion/exclusion criteria Participants had to be at least 18 years old and be English literate, due to the demands of the therapy and the need to complete research instruments. Participants were not required to meet DSM-IV criteria for cannabis abuse or dependence in the past 12 months to be eligible, but must have expressed a desire to cease cannabis use. Individuals who reported using drugs, other than nicotine or alcohol, more than weekly in the past 6 months were also excluded. Their levels of alcohol use were assessed using the Alcohol Use Disorders Identification Test (AUDIT) (Saunders, Aasland, Babor, de la Fuente, & Grant, 1993). Scores in excess of 15, previously associated with alcohol-related social problems, resulted in exclusion from the study (Conigrave, Hall, & Saunders, 1995). Potential participants were also excluded if they had received a formal intervention for cannabis dependence in the past 3 months, or were currently engaged in treatment for any other substance use problem. Those who currently qualified for a DSM-IV Axis I diagnosis were eligible for the program if their symptoms were currently stable or sufficiently mild so as to cause no impact on their ability to participate satisfactorily. No participants were excluded on these grounds Design Following the assessment procedure described below, participants were randomized to one of three conditions: (a) a six-session intervention package incorporating a motivational interview and a standard relapse prevention intervention; (b) a one-session version of the more intensive intervention with a self-help booklet; and (c) assessment and placement in a 24-week delayed-treatment control group.

3 J. Copeland et al. / Journal of Substance Abuse Treatment 20 (2001) 45±52 47 Assessment and therapy were provided by one male and two female registered clinical psychologists Procedure Assessment This project received the required ethics approval from the University of New South Wales Committee on Experimental Procedures Involving Human Subjects. The assessment comprised a structured, clinical interview, in which key data pertaining to demographics, drug use, family history of substance use and psychological problems, pattern and history of cannabis use, cannabis dependence, past treatment experiences, and criminal history were obtained. In addition, participants were required to complete a number of self-administered instruments Psychometric instruments DSM-IV dependence in the past year was assessed using the Composite International Diagnostic Interview, 12-month version (CIDI) (World Health Organization, 1997). The five-item Severity of Dependence Scale (SDS) (Gossop, Griffiths, Powis, & Strang, 1992), originally developed to measure concern over impaired control over opiate use, was adapted to measure cannabis dependence. The use of all four of these instruments in diagnosing cannabis dependence is described in detail elsewhere (Swift et al., 1998). The instruments which were self-administered were: Symptom Checklist-90 (Revised Version SCL-90-R) (Derogatis, 1994) Beck Depression Inventory (BDI) (Beck & Steer, 1987) Cannabis Situational Confidence Questionnaire, and Cannabis Problems Questionnaire The last two instruments were developed for this study. The Situational Confidence Questionnaire was a measure of confidence in resisting cannabis use in a variety of situations or mood states, and was based on the scale developed by Annis and Graham (1988). The Problems Questionnaire was a global measure of cannabis-related problems (adapted from Williams & Drummond, 1994). These are being developed in further research to establish their psychometric properties Analyses The analyses are primarily descriptive in nature and were performed using SPSS for Windows (version 9). Means (SD), and medians for highly skewed data, are reported for continuous data. Categorical variables are described in percentages. When the gender comparisons were carried out, t tests are used for comparisons between normally distributed continuous data; the equivalent nonparametric tests were used for categorical data. Given the exploratory nature of the study, the Bonferroni correction was not applied for the number of comparisons. 3. Results 3.1. Sociodemographics The sociodemographic characteristics of the sample are shown in Table 1. Approximately two thirds of participants were male, with a mean age of 32.3 years. The majority were non-indigenous and Australian-born. Two thirds were in a relationship and only a minority lived alone. More than half of the participants had completed 6 years of secondary school, with only 6.1% not completing the minimum 4 years required. Clients were most commonly employed full-time or in self-employment and reported that they earned their income from employment Cannabis use history and patterns As seen in Table 2, the median age of first cannabis use was 15 years for men and women. The most commonly reported reasons for initial use were curiosity, availability Table 1 Socio-demographic characteristics of the sample, by gender (n = 229) Variable Total (n = 229) Male (n = 159) Female (n = 70) Gender (%) 100% Age (yrs) Mean (SD; range) (7.9; 18±59) (8.3; 18±59) (6.6; 20±50) Country of birth (%) Australia, non-atsi* Australia, ATSI Overseas Education (%) Did not complete secondary school Completed secondary school University ** 35.7 qualification (%) Marital status (%) Married/defacto Relationship, not living together Separated/divorced Single/never married Employment status (%) Full-time/ self-employment Part-time/ casual employment Unemployed Government benefit/pension Student * ATSI: Aboriginal or Torres Strait Islander. ** Significant at P<0.05.

4 48 J. Copeland et al. / Journal of Substance Abuse Treatment 20 (2001) 45±52 Table 2 Patterns of cannabis use, by gender (n = 229 unless specified) Variable Total n = 229 Male n = 159 Female n =70 Age first cannabis use (yrs) Median (range) 15 (7±45) 15 (8± 45) 15 (7± 23) Age first weekly use (yrs) (n = 226) Median (range) 18 (11±47) 17 (11 ± 47) 18 (12±30) Most frequent use in last year (%) (n = 207) Almost daily ± 4 days per week Daily consumption in last month (water pipes) (n = 228) Median (range) 8 (0.1± 125) 8.2 ( < 1± 125) 7.5 (0.1±45) Percentage of weekly income spent on cannabis Mean (SD; range) 27.3 (24.2; 0 ±100) 27.9 (24.6; 0 ±100) 26.0 (23.6; 0 ±100) Number of DSM-IV symptoms among dependent clients (n = 212) Mean (SD; range) 5.9 (1.1; 3 ± 7) 5.9 (1.1; 3 ±7) 6.0 (1.1; 4 ±7) SDS score Mean (SD; range) 9.6 (2.8; 3 ± 15) 9.3 (2.7; 3 ±15) 10.3* (3; 3±15) * P = and peer pressure. Regular weekly cannabis use commenced approximately 3 years later. In the last year, the most frequent use pattern was 5±7 days per week for all but 3 people (1.4%), who were smoking 3±4 days per week. Virtually all (98.7%; n = 226) participants had smoked cannabis in the month prior to assessment, consuming the equivalent of a median of 8 water pipes per day. Cannabis was mixed with tobacco (mean = 38.1%, S.D. =15.1; range = 1±90%) by the majority of clients (91.2%). Smoking cannabis in water pipes was the most common method of use (73.7%), with clients favoring the more potent heads of the plant (93.4%). Cannabis was typically smoked at home (93.0%) in the evening or night (53.7%), although 20.1% usually smoked anytime, and 11% smoked all day. Few reported they usually smoked in the morning (10%). Participants tended to smoke alone (79.5%), and approximately one third (36.1%) of those with partners smoked with them. Women were more likely to smoke with their partners than men (62.8 vs. 25% of men with partners; c 2,1df = 18.8, P<0.001), whose partners were more likely than women's to disapprove of their smoking (61.5% of men in a relationship vs. 34.9% of women; c 2,1df = 8.7, P=0.003). More than half (59.6%) reported they ``sometimes'' or ``often'' exhibited compulsive use patterns, continuing to smoke beyond the stage where they had achieved the desired effect. Three quarters (76.7%) of the sample reported that more than half of their friends used cannabis, with men more likely to report this than women (84.2% vs. 59.4%; c 2,1df = 16.4, P< 0.001). Most cannabis was purchased from a dealer (54.9%) or from friends/relatives (42.9%), with only 21.0% growing at least some of their requirements. A current DSM-IV dependence diagnosis was almost universal (96.4%). Seven participants (3.1%) met criteria for DSM-IV cannabis abuse. The most frequently reported dependence symptom was cannabis withdrawal (95.5%). There were no significant gender differences in severity of DSM-IV cannabis dependence. All clients were dependent according to the Severity of Dependence Scale although women displayed significantly more concern over their use than men. Approximately one in five participants (18.1%) had a cannabis conviction, primarily for possession (14.1%) or growing (6.2%). Convictions were significantly more likely among men than women (22.9% vs. 7.1; c 2, 1df =8.2, P=0.004). However, two thirds (69%) of clients had engaged in nondetected, cannabis-related criminal activity, primarily growing (54.9%) or dealing (37.8%). A further 20.7% had a non-cannabis-related criminal conviction. A small proportion of participants (4.4%) had served time in jail (range of less than a week to 120 months) or juvenile detention (2.6%) Cannabis-related problems Clients were asked to nominate any health problems or benefits they believed they had experienced in the past year due to their cannabis use. Two thirds (69.3%) reported cannabis-related health benefits, overwhelmingly stress relief (80.4% of those who cited benefits). A minority claimed it made them feel good (24.1%) or aided sleep (17.2%). More than three quarters (83.3%) experienced cannabis-related health problems, most commonly respiratory symptoms such as a cough, bronchitis, or asthma (59.5% of those citing problems); psychological problems such as anxiety, depression, or psychosis/paranoia (31.1%); demotivation (30.0%); and memory problems (21.6%). The most commonly endorsed problems ( > 50% of the sample) in the last 6 months using the Cannabis Problems Questionnaire are displayed in Table 3. They centered on: using cannabis in inappropriate situations, interactions with other people, psychological and motivational concerns, physical health, money, and neglect of, or loss of interest in, other activities. In addition, more than one third (37.3%) of parents reported their children had criticized their smoking. Forty

5 J. Copeland et al. / Journal of Substance Abuse Treatment 20 (2001) 45±52 49 Table 3 Those items of the Cannabis Problems Questionnaire endorsed by at least 50% of participants by gender (%) Item Total n = 198 Male n = 136 Female n =62 Driving while stoned (n = 196) Lack of motivation Feeling paranoid or antisocial after smoking (n = 197) Spent more time with smoking friends than other friends Tending to smoke on own more than previously Worried about feelings of personal isolation or detachment (n = 197) Physical neglect (n = 196) Worried about losing touch with friends or family Difficulty getting same enjoyment from interests (n = 196) Worrying about meeting strangers when stoned Pains in chest/lungs after a smoking session Debts Feeling depressed for more than a week Given up hobbies because of smoking (n = 197) Poorer than usual general health (n = 197) Been criticized by friends for smoking too much (n = 196) Making excuses about money (n = 197) Of those in a relationship (n = 93) Spouse complained about smoking (n = 91) Argued with spouse over smoking Of those in employment (n = 152) Gone to work stoned (n = 151) Found work less enjoyable than usual (n = 151) N.B.: relates to the previous 6 months. percent (39.4%) of participants reported they had felt so depressed they felt like doing away with themselves Other drug use A lifetime history of polydrug use was common: Clients had tried on average 6.3 (S.D. =1.8; range = 0±10) drugs other than cannabis. Only 1 client had only used cannabis in their lifetime. More than 50% had tried alcohol (99.1%), tobacco (94.3%), amphetamines, hallucinogens (each 90.8%), and cocaine (81.1%). However, only alcohol and tobacco had been used by more than half the participants (each>75%) on at least a monthly basis. Current drinkers reported a median daily consumption of 0.6 (range = < 1±9.3) standard drinks and those who had consumed alcohol in the past year received an average AUDIT score (possible range = 0 ±40) of 6.0 (S.D. = 3.5; range = 1±15). While there were no gender differences in daily consumption, men received significantly higher AUDIT scores than women (mean of 6.5 vs. 5.1 for women; t 140 = 2.8, P=0.006). Applying the Australian cutoff (Conigrave et al., 1995), 43.6% met the criteria for potentially harmful consumption. Forty-three percent of the sample were current tobacco smokers with a mean daily consumption of 13.6 cigarettes (S.D. = 11.2, range = < 1±50). Males had significantly higher tobacco consumption scores than females (mean of 15.5 vs. 9.7 cigarettes per day; t 96 = 2.44, P<0.02). Smokers received a mean FagerstroÈm Dependence Score of 4.6 (S.D. = 2.1; range = 1±10) (FagerstroÈm & Schneider, 1989). One in five (20.5%) clients reported having experienced a problem with a drug other than cannabis in their lifetime, typically more than 1 year ago. These drugs were most frequently alcohol, tobacco, heroin, and amphetamine. Two thirds (65.9%) reported a family history of alcohol and other drug problems, predominantly alcohol (42.2%), tobacco (40.8%), and cannabis (15.2%) Psychological functioning Psychological screening scales indicated a substantial degree of current psychological distress among trial participants. The mean score on the Beck Depression Scale was 17.2 (S.D. = 10.7; range = 0±40), which exceeds the cutoff Table 4 SCL-90-R raw scores and t scores by gender (n = 199) Scale Raw score (t score a ) Male n = 129 Female n =61 Somatization 1.03 (68)* 1.01 (62) Obsessive± compulsive 1.52 (71)* 1.56 (66)* Interpersonal sensitivity 1.33 (70)* 1.19 (66)* Depression 1.48 (72)* 1.60 (67)* Anxiety 1.18 (72)* 1.07 (66)* Hostility 1.32 (69)* 1.10 (67)* Phobic anxiety 0.51 (68)* 0.57 (62) Paranoid ideation 1.16 (66)* 0.98 (63)* Psychoticism 0.86 (70)* 0.79 (67)* Global severity index (GSI) 1.20 (74)* 1.16 (67)* a Based on adult nonpatient norms for males and females. * Denotes a score significantly higher than the relevant normative nonpatient sample (Derogatis, 1994).

6 50 J. Copeland et al. / Journal of Substance Abuse Treatment 20 (2001) 45±52 of 10 indicative of a clinically significant depression (Beck & Steer, 1987). Scores on the SCL-90-R were similarly elevated. Men and women had significantly higher average scores on a global measure of distress (GSI) than the normative sample of nonpatient adult men and women (Derogatis, 1994). The majority (84.5% of men and 77.0% of women) displayed a clinically significant pattern of scores sufficient to be classified as psychological ``cases'' (see Table 4) (Derogatis, 1994). 4. Discussion Individuals with serious cannabis use disorders, but no other current substance abuse, were attracted to a brief intervention for their cannabis use problems. The demographic profile of the trial participants was consistent with those reported in similar studies, despite differences in sampling and entry criteria. The sample was predominantly male, although there was a higher proportion of females than previously reported (Budney et al., 1998; Stephens et al., 1993). This one-third female representation is more typical of an illicit drug treatment population in Australia (Torres et al., 1995). In general, the sample were aged in their early thirties, and were well educated, in a stable relationship and employed. This high level of social stability is consistent with previous studies of cannabis-dependent individuals in treatment but unlike the typical illicit drug treatment population (Darke, Hall, Heather, Wodak, & Ward, 1992). As seen in other research on substance use disorder treatment-seekers, the majority reported a family history of alcohol and other drug problems (Fletcher, Price, & Cook, 1991). Participants in the trial had typically first used cannabis at age 15 and commenced weekly use around 3 years later. This is 3 years younger than the average age of commencement of cannabis use in the 1995 Australian National Household Survey (Makkai & McAllister, 1997) but similar to the most recent study of cannabis users in treatment (Budney et al., 1998). Almost all of the sample smoked cannabis 5±7 days a week and typically consumed eight water pipes per smoking day. Similarly, they almost universally met diagnostic criteria for cannabis dependence and, with a mean of around 6, criteria fell into the severely dependent range. This pattern of cannabis use is not dissimilar to studies of non ±treatment-seeking samples of cannabis users (Reilly, Didcott, Swift, & Hall, 1998; Swift, Hall, & Copeland, 1998). Given that length and frequency of use do not appear to significantly differ between treatment and nontreatment samples of cannabis users, it is worthwhile to investigate the factors that may lead heavy cannabis users to seek treatment. While there have been no studies addressing this question, it may be the serious constellation of cannabis-related problems that this group reported that differentiates this community from treatment-seeking, heavy, long-term cannabis users. More than three quarters of the sample reported cannabis-related health problems, most commonly respiratory symptoms. While only 43% of the sample were current tobacco smokers with low levels of dependence, the contribution of tobacco to the respiratory symptoms reported by this group is unknown. Psychological problems were also common among the participants with measures of psychological functioning indicating a substantial degree of psychological distress. These include clinically significant depression as measured by the Beck Depression Inventory (Beck & Steer, 1987) and the SCL-90-R (Derogatis, 1994). The latter measure also indicated that the majority of the sample met criteria for psychological ``cases.'' In a further measure, almost 40% of participants reported they felt so depressed they felt like doing away with themselves. This pattern of significant psychological distress has also been reported by the two other studies of cannabis users in treatment (Budney et al., 1998; Stephens et al., 1993). The Cannabis Problems Questionnaire developed for the study also showed a range of psychosocial and healthrelated harms associated with cannabis use in the previous 6 months. These include using in inappropriate situations such as driving and working while stoned, detrimental effects on relationships with others Ð including children, psychological and motivational concerns, physical health, financial problems, and neglect of activities such as hobbies or work. Financial and legal problems were also a feature among this sample, with participants spending approximately a quarter of their income on cannabis and only 21% growing even some of their cannabis requirements. Approximately one in five participants had a cannabis-related conviction but more than two thirds reported they had engaged in nondetected cannabis-related criminal activity. Similar studies have also reported that financial and legal problems featured as reasons for wanting to reduce or abstain from cannabis use (Budney et al., 1998; Stephens et al., 1993). Consistent with similar studies, this group had a lifetime history of polydrug use with only one participant having only ever used cannabis. The patterns of current substance use, however, were constrained by the exclusion criteria applied in this study. Despite this, more than 40% of participants were drinking alcohol at potentially harmful levels. There were a number of clinically relevant gender differences found within the study group that have not previously been reported in the cannabis treatment literature. Consistent with other substance use treatment studies, women were significantly more likely to have a cannabisusing partner than were males, and as a consequence were significantly less likely to have a partner who disapproved of their cannabis use (Macdonald, 1987). Interestingly, women were also significantly less likely to have a heavy cannabis-using social network. This may be reflective of the

7 J. Copeland et al. / Journal of Substance Abuse Treatment 20 (2001) 45±52 51 greater social stigma experienced by women with substance use disorders (Copeland & Hall, 1992). Finally, while women had similar patterns of cannabis use, they had significantly higher SDS scores, which reflects a greater concern about their cannabis use and the perceived difficulty of quitting. On the other hand, males had significantly higher levels of alcohol and tobacco use, more criminal convictions, and higher levels of psychological distress as measured by the SCL-90-R. These findings suggest that treatment providers would benefit from ensuring that they assess and intervene in those issues which are particularly gender-sensitive, such as relationships, concerns over use, legal problems, and patterns of other substance use. 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