Changes in psychological characteristics of drug abusers in a group counselling programme

Sections

ABSTRACT
Introduction
The group counselling programme
Methodology
Discussion

Details

Author: T. H. ONG
Pages: 35 to 47
Creation Date: 1994/01/01

Changes in psychological characteristics of drug abusers in a group counselling programme

T. H. ONG
Senior Lecturer, Department of Social Work and Psychology, National University of Singapore, Kent Ridge, Singapore

ABSTRACT

One hundred male ex-addicts who were provided with an indigenized group counselling programme in after-care service during their two-year compulsory supervision were administered two psychological tests at the beginning and the end of the programme. The tests were eight rating scales on attitudinal and psychological characteristics and the 16 PF questionnaire. t tests show that the successes have changed their attitude towards drug-taking from "favourable" to "unfavourable", and that they have improved in their psychological state and functioning.

Introduction

A number of researchers have studied biosocial variables of drug abusers in successful treatment [ 1] - [ 4] . Furthermore, some other studies looked into personality traits of successes and failures in drug rehabilitation programmes [ [ 5] - [ 13] ] (see table 1). They appeared to show that ex- addicts who had a low level of defensiveness, anxiety, frustration and aggressiveness and a high personality integration tended to succeed in their treatment programme. However, comparatively fewer researchers investigated further the changes in drug addicts who had been treated in any rehabilitation programme. Nevertheless, all of them showed that treated ex-addicts were more likely to become better adjusted and to make improvements in their psychological functioning [ [ 14] - [ 17] ].

The present paper attempts to find out what changes there were in a group of ex- addicts who had completed a group counselling programme in aftercare service during their two -year compulsory supervision.

The group counselling programme

In the programme or model, trained group leaders conduct weekly one-hour sessions for drug supervisees (ex-addicts who are placed under two-year compulsory supervision after discharge from drug rehabilitation centres (DRCs)) for the first six months followed by fortnightly one -hour sessions for another three months. This amounts to a total of about 30 sessions or hours for the whole programme. Each group starts with about 10 drug supervisees without replacement throughout the whole period. Topics to be discussed are decided by the group itself according to the priority of the current needs of the supervisees. Each of them requires a number of sessions for thorough exploration before going to the next. Topics such as employment, interpersonal relationships, family troubles, health concerns, financial problems, and supervision and urine -test issues are usually covered. Members of the group should have opportunities to learn coping and social skills throughout the programme.

Table 1. Relevant studies on psychological variables of successes and failures in drug treatment programmes

Authors

Year

Subjects

Instruments

Findings

G. E. English and
1972
190 male federal prisoners,
Lexington personality inventory
Opiate addicts with high drug association,
J. J. Monroe [5]
 
66 per cent completed probation
 
depression and emotional deprivation scores
   
289 opiate addicts, 47.4 per cent
Jones verbal facility test
were more likely to fail
   
were treated successfully
   
       
Opiate addicts with middle-class values, social
       
desirability and defensiveness were more likely
       
to succeed.
E. L. Edelstein [6]
1976
44 consecutive patients
10 predictive factors:
23 out of 44 with high scores on thew 10 factors
   
seeking assistance at a
Diagnostic categories other
were taken in therapy and the success rate was
   
drug abuse clinic
than sociopathy
unusually high
     
Short duration of addiction
 
     
Severity of addiction
 
     
Social and work function
 
     
Ability for some introspection
 
     
Ability to continue treatment session
 
     
Ability to postpone satisfaction
 
     
Frustration and anxiety level not too low
 
     
Low self-destructive tendencies
 
     
Some indication that indulgence in
 
     
drugs serves some temporary self-
 
     
therapeutic device
 
H. IC Wexler and
1977
809 residents who were
MMPI
Drop-outs were generally more defensive and
G. de Leon [7]
 
primarily male and black
Beck depression inventory-
disturbed
     
shortened manifest anxiety scale
 
R. Bradley and
1978
20 male airmen,
16 PF questionnaire
The sensation-seeking scale has the best
D. L Redfering [8]
 
mean age = 20.6 yrs,
Tennessee self-concept scale
potential value in predicting successful
   
successfully completed
Sensation-seeking scale
rehabilitation of military drug abusers
   
a treatment programme
   
K. Goodkin and
1982
52 opiate addicts,
Rokeach dogmatism scale
Abstainers were characterized by less dogmatism,
K. E. Wilson [9]
 
all adults
Reid-Ware three-factor internal-
higher education and personality integration,
   
external scale
fewer aggressive incidents, and previous drug
 
     
Tennessee self-concept scale
arrests and older age
F. Biasco,
1983
71 residents in a therapeutic
MMPI
Successfully treated males scored significantly
C. O. Fritch and
 
community,
 
higher on hypochondriasis, hysteria and
D. L. Redfering [10]
 
median age = 23 years
 
masculinity-femininity
       
Successfully treated females scored significantly
       
higher on social introversion
       
Unsuccessfully treated females scored significantly
       
higher on masculinity-femininity than successfully
       
treated females
R. J. Craig and
1988
94 programme completers,
Adjective check-list
Drop-outs had higher needs for autonomy and
E. Olson [11]
 
22 programme drop-outs,
 
aggression, and lower needs for deference,
   
all treated in a Veteran's
 
nurturance and affiliation
   
Administration facility
   
M. J. Stark and
1988
100 consecutive admissions
Millon clinical multiaxial inventory
The high early attrition rate was due more to the
B. K Campbell [12]
 
to a community drug abuse
 
nature of the disorder rather than its severity
   
treatment centre, aged
   
   
14-46 years
   
T. H. Ong [13]
1990
Experimental group
8 rating scales on attitudinal and
Successful ex-addicts tend to be mature, realistic,
   
= 100 ex-addicts
psychological characteristics
emotionally stable (C), trusting (L), and less
   
mean age = 27 years
Part of 16 PF
anxious (Q11)
   
Control group
   
   
= 89 ex-addicts
   
   
mean age = 25 years
   
Note:MMPI = Minnesota multipersonality inventory.

The rationale of the model is that statistically, about half of the drug supervisees are re-admitted to DRCs, or arrested for drug-related criminal acts, or default within one year after release from DRCs, and another 25 per cent in the following year [ 18] . According to the volunteer after-care officers who are helping them, more drug supervisees tend to relapse within six months after leaving DRCs mainly because they are usually overwhelmed by their difficulties and problems as well as feelings of frustration and inferiority. Thus, the first six months of supervision should be considered an extremely critical period for drug supervisees. It is during that period of time that they need the most help. Programmes that are able to meet the needs of clients at the right time are more likely to be helpful and effective.

Methodology

Subjects

In the pilot project for the programme, a total of 189 ex -addicts who were English-speaking and without individual aftercare service were selected from 2,776 male drug supervisees in November 1984 [ 4] . These ex-addicts were subsequently assigned at random to the experimental and control groups respectively. The former consisted of 100 ex-addicts because 10 formed a group for a group leader, while the controls were 89 ex -addicts.

In the study, only the 100 ex-addicts of the experimental group were involved. They were provided with the group counselling programme. Their detailed bio-social data are listed in table 2.

Of the 100 ex-addicts, 45 were Chinese, 39 Malays, 12 Indians and 4 others. All were male and citizens or permanent residents of Singapore, an island State, which is a multiracial, multicultural, multireligious and multilingual society. The ethnic composition includes Chinese (76 per cent), Malays (15 per cent), Indians (7 per cent), Eurasians and others (2 per cent). The majority of the Chinese are Buddhists, Taoists or ancestor worshippers, while others are Christians or Catholics. The Malays are Muslims who adhere to Islamic laws. The Indians tend to believe in Hinduism. Some of them are Christians or Muslims. In formal education, they have been educated in their mother tongue and/or English for six years in primary schools and 4 to 6 years in secondary education.

Table 2. Selected social data on subjects (N = 100)a/

Item

Number of subjects

Item

Number of subjects

A. Demographic profile of subjects
 
B. Institutional experience of subjects
 
Age b/
 
1.Treatment history
 
20 and below
4
DRC admissions
 
20-24
26    
25-29
43 1 14
30-34
19 2 38
35-39
7 3 41
40+
1 4 5
    5+ 2
Marital status:
     
   
Length of supervision
 
Single
78    
Married
20
6-9 months
0
Divorced/widower
2
10-13 months
21
   
14-17 months
19
Education:
 
18-21 months
40
   
22-24 months
20
None
0    
Primary
34
2 Criminal history
 
Secondary
65    
Post secondary
1
Criminal offences
 
Ethnic group:
 
None
33
   
Related to drugs
53
Chinese
45
Robbery, theft, gambling etc.
14
Malay
39    
Indian
12
Previous convictions
 
Others
4    
Employment
  1 35
    2 18
Employed, full-time
51 3 7
Employed, part-time
4 4 2
Unemployed
45 5 5
a/ Two were later enlisted into national service during the project.
b/ Range - 17-42: average - 27.

Instruments

A set of eight rating scales on attitudinal and psychological characteristics and part of the 16 PF questionnaire (form A) were used. The eight Likert-type rating scales which were constructed for studying the personality traits of drug abusers include such characteristics as attitude towards drug-taking, interpersonal relationships, self-image, personal values, risk-taking tendency, motivation, rebelliousness and pleasure- seeking [ 19] . Each scale consists of 12 times. The possible lowest score of each scale is 12 points, the possible highest is 60, while the mid-score is 36. All scales have been shown to have satisfactory face validity and content validity as well as high reliability ranging from .83 to .98. In other words, the test is reliable and able to measure properly and accurately the psychological characteristics of drug abusers.

The 16 PF was partially employed to measure mainly two characteristics: emotional stability and anxiety. The factors related include C (emotionally less stable versus emotionally stable), H (shy, timid versus uninhibited, socially bold), L (trusting versus suspicious), 0 (secure, self - assured versus insecure, self -reproaching), Q3 (undisciplined, following own urges versus controlled, exacting will power), Q4 (relaxed, composed versus tense, frustrated), and Q11 (low anxiety versus high anxiety). The score of each factor ranges from 1 to 10, with 1 to 3 as low, 5 to 6 as average and 8 to 10 as high.

Procedure

The two tests were administered to all the 100 subjects at the commencement of the group counselling programme in November 1984 at their various urine-test centres. However, 92 subjects (or 94 per cent) completed them and had a full set of test scores on both tests for analysis (see table 3). Later, it was found that they included 50 successes and 42 failures.

At the end of the group counselling programme in 1985, the same tests were given again but only to those who were still available in the group (known as success cases at that point in time). The number was 60, for 45 of whom complete data from both tests were available. Again it was found later in the follow-up that there were 39 successes and six failures.

The successes comprise ex-addicts who have not been arrested for drug-taking or drug-related crimes, or have not absconded or defaulted during the period under study. Otherwise, they are considered failures.

t tests, a method in statistics used to find out how much two or more groups of people or things are different from each other, were employed to examine the differences in the 15 psychological characteristics between groups or subjects at different points in time.

Table 3. Number of subjects and full set of test data available at different points in time

Time

Number of subjects

Full test data

Percentage

November 1984
100 a/
92 94
   
50 (successes)
 
   
42 (failures)
 
October 1985
     
Successes
60 (61%)
39 65
Failures
38 (49%)
6 16
October 1986
     
Successes
52 (53%)
   
Failures
46 (47%)
   
a/ Two of them were later enlisted into national service (during the project).

Findings

At the beginning of the programme, there were significant differences between successes and failures in factors C, L and Q11. They show that the successes were more stable emotionally, mature, calm, realistic and trusting, but less anxious than were the failures (see table 4). However, both groups did not differ significantly from each other at the end of the nine-month programme (see table 5).

As shown in table 6, the successes had significant changes in some psychological characteristics during the group counselling programme. The changes included:

  1. Attitude towards drug-taking. The success cases indicated less favourable attitudes towards using illicit drugs, their legalization and their effects at the end of the programme;

  2. H (shy versus socially bold). The successes displayed a change from being, shy, timid and threat-sensitive to becoming venturesome, uninhibited and socially bold towards the end of the programme;

  3. O (secure versus insecure). The successful ex-addicts also experienced a change from feeling insecure, apprehensive, self - reproaching, worrying and troubled to feeling secure, self - assured, complacent and secure during the programme;

  4. Q11 (low anxiety versus high anxiety). The successes also changed during the programme from a higher level of anxiety to a lower level of anxiety.

Table 4. t test an psychological characteristics between successes and failures of the subjects at the beginning of the group counselling programme (1984)

 

Success cases (N=52)

Failures (N=40)

Item

X

S.D

X

S.D

t

Attitude towards drug- taking
25.7 7.1 25.7 6.6 0.00
Interpersonal relationships
44.3 5.8 44.1 5.9 .16
Self-concept
42.0 7.6 42.6 7.0 -.38
Personal values
47.6 5.6 45.8 5.0 1.58
Risk- taking tendency
30.0 7.6 29.8 5.3 .14
Motivation
42.3 5.4 41.6 4.7 .65
Rebelliousness
28.6 5.4 29.4 6.0 -.66
Pleasure-seeking
28.9 7.3 30.8 6.9 -1.25
Emotional instability versus stability (C)
4.9 1.9 3.9 1.6 2.65 a/
Shy versus socially bold (H)
4.6 1.7 4.4 1.5 .58
Trusting versus suspicious (L)
6.1 1.7 6.9 1.6 -2.27 b/
Secure versus insecure (0)
6.8 1.7 7.2 1.9 - 1.05
Undisciplined versus controlled (Q3)
5.4 1.5 5.1 1.8 .86
Relaxed versus tense (Q4)
5.6 1.8 6.3 1.9 -1.79
Low anxiety versus high anxiety (Q11)
6.3 1.7 7.2 1.6 -2.55 b/
Notes:
N
Number of cases or persons under study.
X
Mean, the average of scores.
S.D.
Standard deviation, a measure of variation.
 
It measures the average variations from the mean. The greater the variability around the mean of a distribution of scores, the larger the S.D. Therefore, S.D. = 5.0 indicates greater variability than S.D. = 3.0.
t test
A statistical method used to determine whether the mean performances of two groups are significantly different. The two groups in this study refer to success and failure cases.
p<.05
This is related to the level of significance. P is the symbol used to show probability levels. When the chance probability of an event's occurrence is 5 in 100, it is said that the event is statistically significant at 5 per cent or .05 level. It is written as p<.05, which means that there are less than 5 chances in 100 that the results are accidental. Therefore, in the present study it means that there are less than 5 chances in 100 that the difference in a trait between successes and failures determined by t test will occur by accident or chance factors. In other words, there is more than 95 per cent confidence in getting the result not by chance. Therefore, the difference obtained is significant.
p<.01
Same as above, meaning that there is less than one chance in 100 that the difference in a trait between successes and failures determined by t test will occur by accident or chance factors. In other words, there is more than 99 per cent confidence in getting the difference not by chance. Therefore, the difference obtained is very significant.
df=90
df = degree of freedom refers technically to freedom of variation among a set of scores. If there is a sample of six scores, then five are free to vary while only I is fixed by value. Therefore, in a single sample of subjects, df = N-1 = 5. In table 4, there are 2 samples, N = 52 and N = 40, so df = 52 + 40 - 2 = 90. df varies directly with sample size and goes to determine the sample of the sampling distribution of differences. The larger the sample size, the greater the df. The greater the df, the closer the distribution of differences comes to an approximation of the normal curve, which is usually bell-shaped.
a/ p<.01 df = 90. b/ p<.05 df = 90.
 

Table 5. t test on psychological characteristics between successes and failures of the experimentals at the end of the group counselling programme (1985)

 

Success cases (N=39)

Failures (N=6)

 

Item

X

S.D

X

S.D

t

Attitude towards drug-taking
22.2 7.1 21.5 9.6 .21
Interpersonal relationships
46.7 6.6 47.3 5.9 -.21
Self-concept
44.2 6.7 43.8 5.7 .14
Personal values
48.1 6.3 47.7 5.8 .14
Risk-taking tendency
29.9 6.6 26.3 4.7 1.26
Motivation
42.9 5.6 41.8 2.6 .46
Rebelliousness
26.8 7.3 25.5 5.9 .41
Pleasure-seeking
26.7 8.2 28.7 2.8 -.58
Emotional instability versus stability (C)
5.3 1.5 4.7 1.2 .91
Shy versus socially bold (H)
5.0 1.7 4.0 2.2 1.26
Trusting versus suspicious (L)
5.9 1.5 5.8 1.3 .15
Secure versus insecure (0)
6.0 1.9 7.5 1.2 -1.84
Undisciplined versus controlled (Q3)
6.0 2.3 6.2 1.7 -.20
Relaxed versus tense (Q4)
5.1 1.8 5.5 1.0 -.52
Low anxiety versus high anxiety (Q11)
5.6 1.7 6.3 0.8 -.97
Note:See table 4 for notes.

Table 6. t test on psychological characteristics of successes between the beginning (1984) and the end (1985) of the group counselling programme

 

Success cases at beginning of group counselling (N=39)

Success cases at end of group counselling (N=39)

 

Item

X

S.D

X

S.D

t

Attitude towards drug-taking
26.1 7.3 22.2 7.1 2.36 a/
Interpersonal relationships
44.3 5.9 46.7 6.6 -1.67
Self-concept
41.6 7.9 44.2 6.7 -1.55
Personal values
47.4 5.9 48.1 6.3 -.50
Risk-taking tendency
30.9 7.8 29.8 6.6 .66
Motivation
41.6 5.6 42.9 5.6 -1.01
Rebelliousness
29.5 5.2 26.8 7.3 1.86
Pleasure-seeking
29.9 7.5 26.7 8.2 1.78
Emotional instability versus stability (C)
4.9 2.0 5.3 1.5 -.99
Shy versus socially bold (H)
4.1 1.6 5.0 1.7 -2.38 a/
Trusting versus suspicious (L)
6.3 1.6 5.9 1.5 1.12
Secure versus insecure (0)
6.9 1.7 6.0 1.9 2.18 a/
Undisciplined versus Controlled (Q3)
5.2 1.5 6.0 2.3 -1.80
Relaxed versus tense (Q4)
5.7 1.9 5.1 1.8 1.41
Low anxiety versus high anxiety (Q11)
6.5 1.7 5.6 1.7 2.31 a/
Note: See table 4 for notes.
a/ p<.05 df = 76.

As with the successes, the failures also showed significant changes during the programme (see table 7). The changes included:

  1. 04 (relaxed versus tense). The failures experienced a change from a state of being tense, frustrated, driven and overwrought to a state of being relaxed, unfrustrated, composed and tranquil;

  • Q11 (low anxiety versus high anxiety). The failures felt more anxious at the beginning of the programme and less anxious at the end of it.

Table 7. t test on psychological characteristics of failures at the beginning (1984) and the end (1985) of the group counselling programme

 

Failure cases at beginning of group counselling (N=6)

Failure cases at end of group counselling (N=6)

 

Item

X

S.D

X

S.D

t

Attitude towards drug-taking
24.8 3.4 19.8 8.5 1.22
Interpersonal relationships
42.8 7.8 47.3 5.9 -1.03
Self-concept
41.3 8.3 43.8 5.7 -.56
Personal values
43.7 7.4 47.7 5.8 -.95
Risk- taking tendency
28.2 4.4 26.3 4.7 .66
Motivation
42.5 4.5 41.8 2.6 .30
Rebelliousness
27.8 7.7 25.5 5.9 .53
Pleasure-seeking
27.3 6.1 28.7 2.8 -.47
Emotional instability versus stability (c)
3.7 1.9 4.7 1.2 -1.00
Shy versus socially bold (H)
4.3 1.9 4.0 2.2 .23
Trusting versus suspicious (L)
6.5 1.9 5.8 1.3 .68
Secure versus insecure (0)
7.7 0.8 7.5 1.2 .31
Undisciplined versus Controlled (Q3)
4.5 1.2 6.2 1.7 -1.83
Relaxed versus tense (Q4)
7.0 1.1 5.5 1.0 2.26 a/
Low anxiety versus high anxiety (Q11)
7.7 1.0 6.3 0.8 2.45 a/
Note: See table 4 for notes.
a/ p<.05 df = 10.

Discussion

Obviously, the results of the study indicate two changes in the successful ex-addicts who have gone through an indigenized group counselling programme in after-care service:

  1. A change in attitude. The ex-addicts had a less favourable attitude towards drug-taking at the end of the programme. That is a positive change;

  2. An improvement in psychological state and functioning. The ex-addicts became more sociable, secure, confident and less anxious at the end of the programme. That improvement has been shown in other studies [15-17].

In the programme, the ex-addicts had ample opportunities to discuss the problems and difficulties that they were facing, to explore different ways of dealing with them, and to learn coping skills from other members and the group leader. Throughout the programme, they also had chances to exchange views and experiences with each other as well as to give and receive support to and from each other. In the group, they also found that other members like themselves had various problems or troubles and wanted to change for the better. That not only helped them to calm down and feel comfortable, secure and less anxious, but also to become more confident in tackling their problems. With group cohesiveness and support, they became more positive towards life.

Surprisingly, it was also found that the failures changed. They became more relaxed, unfrustrated and less anxious at the end of the programme. However, caution must be exercised since the group size is small (N=6). Why they failed could be due to other factors, either psychological or social characteristics, or both.

In that context, it would be interesting to know at what point the failures drop out of the programme and what changes they may have undergone. Such questions could provide areas of study for future research. Furthermore, a more comprehensive design of future research should include more directly relevant psychosocial factors such as education, employment, criminality, drug experience, anxiety, attitude towards drug-taking and other personality variables.

In conclusion, the ex-addicts who were provided with group counselling during the period of their supervision tend to benefit from the service, since they need help most on discharge from drug rehabilitation centres.

References

001

R. Stephens and E. Cottrell, "A follow-up study of 200 narcotic addicts committed for treatment under the Narcotic Addict Rehabilitation Act", British Journal of Addiction, vol. 67, 1972, pp. 45-53.

002

D. Waldorf and P. Biernacki, "Natural recovery from heroin addiction: A review of the incidence literature", Journal of Drug Issues, vol. 9, No. 2 (1979), pp. 281-289.

003

N. R. Mann, V. D. Charuvastra and V. Y. Murthy, "A diagnostic tool with important implications for treatment in addiction: identification of factors underlying relapse and remission time distribution", The International Journal of the Addictions, vol. 19, 1984, pp. 25-34.

004

T. H. Ong, "A follow-up study on the drug supervisees who have gone through an indigenized group counselling programme in Singapore", paper presented at the International Conference for the Advancement of Counselling, Helsinki, 1990.

005

G. E. English and J. J. Monroe, "A comparison of personality and success rates of drug addicts under two outpatient supervisory systems", The International Journal of the Addictions, vol. 7, No. 3 (1972), pp. 451-460.

006

E. L. Edelstein, "Treatability of addicts: hypothesis and results", British Journal of Addiction, vol. 71, No. 3 (1976), pp. 281-284.

007

H. K. Wexler and G. de Leon, "The therapeutic community: multivariate prediction of retention", American Journal of Drug and Alcohol Abuse, vol. 4, No. 2 (1977), pp. 145-151.

008

R. Bradley and D. L. Redfering, "Drug abuses in the military: correlates of successful rehabilitation", Journal of Clinical Psychology, vol. 34, No. 1 (1978), pp. 233-237.

009

K. Goodkin and K. E. Wilson, "Amenability to counselling of opiate addicts on probation or parole", The International Journal of the Addictions, vol. 17, No. 6 (1982), pp. 1047-1053.

010

F. Biasco, C. 0. Fritch and D. L. Redfering, "Personality differences between successfully and unsuccessfully treated drug abusers", Social Behaviour and Personality, vol. 11, No. 1 (1983), pp. 105-111.

011

R. J. Craig and R. E. Olson, "Differences in psychological need hierarchy between program completers and dropouts from a drug abuse treatment program", American Journal of Drug and Alcohol Abuse, vol. 14, No. 1 (1988), pp. 89-96.

012

M. J. Stark and B. K. Campbell, "Personality, drug use, and early attrition from substance abuse treatment", American Journal of Drug and Alcohol Abuse, vol. 14, No. 4 (1988), pp. 475-485.

013

T. H. Ong, "The differences in psychological characteristics between success and failure cases in a group counselling programme in aftercare service", Paper presented at the 12th IFNGO International Conference, Singapore, 12-16 November 1990.

014

R. Harris and M. W. Linn, "Differential relapse of heroin and non- heroin abusers to inpatient treatment", American Journal of Drug and Alcohol Abuse, vol. 15, 1978, pp. 179-190.

015

G. deLeon and N. Jainchill, "Female drug abusers: social and psychological status 2 years after treatment in a therapeutic community", paper presented at the National Alcohol and Drug Conference, Washington D.C., 1980.

016

A. McLellan and others, "A prospective study of patient-treatment matching", Journal of Nervous and Mental Disease, vol. 171, 1983, pp.597-605.

017

R. J. Craig, R. Olson and G. Shalton, "Improvement in psychological functioning among drug abusers: in-patient treatment compared to outpatient methadone maintenance', Journal of Substance Abuse Treatment, vol. 7, No. 1 (1990), pp. 11-19.

018

Ministry of Home Affairs, Review of a Drug Programme (Singapore, 1987), a restricted report.

019

T. H. Ong, "Construction of rating scales for measuring attitudinal and psychological characteristics of drug abusers", The International Journal of the Addictions, vol. 23, No. 9 (1988), pp. 967-989.