A 10-year retrospective study of inpatient adolescents with schizophrenia/schizoaffective disorder and substance use

Abstract

The comorbidity of schizophrenia/schizoaffective disorder and substance use is a major psychiatric concern that is associated with aggressive and suicidal behavior. This study investigated the clinical correlates and characterizes adolescent psychotic inpatients with and without comorbid substance use. We performed a retrospective study of 188 adolescent inpatients who were admitted between the years 1994 and 2004 to the inpatient unit of Geha Mental Health Center and who were diagnosed as suffering from either schizophrenia or schizoaffective disorder. The substance-using psychotic inpatients were found to have more relatives with substance-related disorders, fewer comorbid anxiety disorders, lower scores on the Brief Psychiatric Rating Scale and Hamilton Scale for Depression, higher scores on the Overt Aggression Scale, and they were more suicidal than the nonsubstance using inpatients. Adolescent inpatients with schizophrenia and schizoaffective who use substances possess differential clinical characteristics and particular correlates that justify adopting a specific approach to this high-risk clinical subgroup.

Introduction

The comorbidity of schizophrenia and substance abuse is well documented, with up to 60% of the patients being reported using or abusing illicit drugs [1], [2], [3], [4]. The rates in inpatient settings are in the same range and are sometimes even higher [4], [5], [6], [7], [8].

Substance abuse among patients with schizophrenia is considered a major clinical and public health concern [9]. Apart from tobacco consumption (over 70%), the most frequently used substances are alcohol (37%), cannabis (23%), and stimulants or hallucinogens (13%) [10], [11], [12], [13]. The abuse of most of these substances has been linked to psychotic symptom exacerbation, repeated hospitalizations, poor social functioning, homelessness, increased suicide risk, and poor response to treatment [5], [14], [15], [16].

To better understand the relationship between schizophrenia and the use and abuse of substances at rates far exceeding those found in the unaffected population, several models have been proposed [9], [17], [18], [19], [20]. The etiological model hypothesizes that drug abuse is a causative factor in the development of this disease in a subgroup of patients with schizophrenia [21], [22], [23], [24]. Alternatively, the dopamine model suggests that disturbances in the reinforcement and reward function of the dopamine-producing areas of the brain may increase the vulnerability to both schizophrenia and drug abuse in some patients [25]. A third model, the socializing effects paradigm, considers drug use by patients with schizophrenia to be interpersonally reinforcing as it renders handicapped and isolated patients' social identity and group [26]. Finally, the self-medication model suggests that patients suffering from schizophrenia may use drugs to ameliorate depression [27], negative symptoms [28], or neuroleptic-induced extrapyramidal side effects [29].

A prospective study in adults has found that substance abuse in patients with schizophrenia is associated with suicidality and impulsivity, but the data collected revealed no correlation with scores on the Chapman Physical Anhedonia Scale, the Positive and Negative Syndrome Scale, the Clinical Global Improvement scores, or with treatment response and demographic variables [30]. Another recent study found that schizophrenic patients with substance use were younger, more likely to be male, had a shorter duration of illness, and had more police contact, but symptoms, service use, or social functioning were only minimally affected [31]. A schizophrenic patient's history of substance use was shown to be among the predicting factors of aggression during hospitalization [32] and has been reported to be associated with an earlier age of onset of the psychotic disorder [33], [34]. Finally, a longitudinal study of adult schizophrenia and schizoaffective inpatients found that substance abuse among this group was correlated with fewer negative and positive symptoms, better sexual adjustment, worse school performance during adolescence, and greater family histories of drug abuse [5]. Cannabis, alcohol, and cocaine were the most commonly used drugs in that cohort. The authors concluded that patients with schizophrenia who abuse drugs may represent a subgroup with a different prognosis.

To the best of our knowledge, similar studies have not been performed in adolescents. The developmental phase of adolescence is regarded as a time of vulnerability to the adverse effects of misused substances upon psychological functioning [35]. Drugs and alcohol may interfere with learning, social and personal development, may aggravate preexisting emotional distress, and may lead to a progression to the use of other substances, possibly in increased doses. These implications may well be more severe in adolescent patients with schizophrenia.

A review of the literature regarding suicidality and substance abuse indicates that drug and alcohol use was found to be associated with suicidal behavior not only in adults [36], [37] but also in adolescents as well [38], [39], [40], [41]. Schizophrenia by itself is associated with an increased rate of suicidality; thus, substance use in these patients is expected to further increase the risk of potentially lethal self-injurious behavior. We have been unable to find a comprehensive study on the effect of substance use on suicidal behavior among adolescent inpatients with schizophrenia.

The issue of the underrecognition of substance use and abuse by medical staff has been dealt with previously [42], [43]. For example, it has been noted recently that although substance misuse is very common in psychiatric patients [3], most patients were not questioned about such behavior by admitting psychiatrists [44]. General physicians were reported long ago to be poor at taking substance use and abuse histories and alcohol history in many clinical settings [45]. This finding emphasizes the importance of obtaining more data on the clinical features of substance-using and substance-misusing adolescent patients.

We performed a retrospective study of inpatient adolescents with schizophrenia and schizoaffective disorder. The goal of this study was to identify the clinical correlates and to characterize adolescent psychotic inpatients with and without comorbid substance use.