An Examination of DSM-IV Inhalant Use Disorders Using a Dimensional Approach

Background and purpose: Inhalant use is among the most dangerous and poorly understood forms of substance use. General population, clinic, and criminal surveys consistently show that many youth have used inhalants, but little is known about the structure and validity of DSM-IV inhalant use disorders (IUDs). This information is necessary in order to develop psychometrically sound assessment tools, understand the course of treatment, and develop empirically supported interventions. Therefore, the purpose of this study was to examine the validity of IUDs and whether a distinction between abuse and dependence is empirically supported.

Methods: Data were collected via a cross-sectional survey with structured psychiatric interviews including Diagnostic Interview Schedule assessments of past-year/lifetime IUDs. Current residents (N = 723; 98% response rate) of 32 Missouri Division of Youth Services residential rehabilitation facilities participated. Most youth were male (87 %) and in mid-adolescence (M =15.5, SD = 1.2); 38.6 % (N = 279) had used inhalants. Descriptive statistics were used to summarize the rate of each DSM-IV diagnostic criterion for abuse and dependence among inhalant users. Rasch analysis was used to examine the underlying unobserved latent trait (inhalant use severity).

Results: Among inhalant users, 62 (22.2 %) met DSM-IV inhalant abuse criteria and 79 (28.3 %) met inhalant dependence criteria. Six of 10 DSM-IV IUD diagnostic criteria were met by >10 % of the total sample. The most common abuse criteria were use in physically hazardous situations (32.6%) and recurrent failure to fulfill major role obligations (23.7%). The most common dependence criteria were tolerance (45.5%) and continued use despite knowledge of recurrent physical or psychological problems. Rasch analysis suggested that abuse and dependence criteria represented a single underlying dimension of inhalant use severity. The combined set of items showed a high degree of intercorrelations (alpha = .98) and explained approximately 66% of the variance. Analyses also showed the presence of symptom clusters that included both abuse and dependence symptoms. Clusters included the most common symptoms previously noted, in addition to use despite legal issues and giving up other activities or spending a lot of time obtaining, using and recovering from their effects.

Conclusions and implications: Contrary to prior evidence, this study did not support the distinction between inhalant abuse and dependence. Instead, these results suggest that involvement with inhalants may be best viewed on a single dimension of severity. These results raise important issues respect to assessment and overall need for services related to inhalants. More specifically, the evidence for a single dimension and the observation of symptom clusters raises the possibility that some youth may meet criteria for abuse but have much more serious problems than what the disorder connotes. This could result in an inadequate amount of treatment for a significant number of youth with inhalant-related problems. Social workers should consider issues of inhalant use severity in addition to the current DSM-IV formulation that differentiates abuse from dependence.