Transitions from first substance use to substance use disorders in adolescence: Is early onset associated with a rapid escalation?

Abstract

Background

Early substance use (SU) in adolescence is known to be associated with an elevated risk of developing substance use disorders (SUD); it remains unclear though whether early SU is associated with more rapid transitions to SUD.

Objective

To examine the risk and speed of transition from first SU (alcohol, nicotine, cannabis) to SUD as a function of age of first use.

Methods

N = 3021 community subjects aged 14–24 years at baseline were followed-up prospectively over 10-years. SU and SUD were assessed using the DSM-IV/M-CIDI.

Results

(1) The conditional probability of substance-specific SU-SUD transition was the greatest for nicotine (36.0%) and the least for cannabis (18.3% for abuse, 6.2% for dependence) with alcohol in between (25.3% for abuse; 11.2% for dependence). (2) In addition to confirming early SU as a risk factor for SUD we find: (3) higher age of onset of any SU to be associated with faster transitions to SUD, except for cannabis dependence. (4) Transitions from first cannabis use (CU) to cannabis use disorders (CUD) occurred faster than for alcohol and nicotine. (5) Use of other substances co-occurred with risk and speed of transitions to specific SUDs.

Conclusion

Type of substance and concurrent use of other drugs are of importance for the association between age of first use and the speed of transitions to substance use disorders. Given that further research will identify moderators and mediators affecting these differential associations, these findings may have important implications for designing early and targeted interventions to prevent disorder progression.

Introduction

Early onset of substance use (SU) is related to an elevated risk of substance use disorder (SUD) (Grant and Dawson, 1997, DeWit et al., 2000, Breslau et al., 1993, Chen et al., 2005). Available data though suggest that the relationship is complex and our knowledge about the speed of transition from first use to DSM-IV abuse or dependence in adolescence and particularly of age at first use and its relation to the speed of transitions for different substances is still limited (Chen et al., 2005). This is likely due to methodological factors (e.g. differences in definitions of early onset) and a deficit of prospective-longitudinal studies on SUD incidence in adolescence (Rehm et al., 2005).

This paper investigates for various substances, whether early onset of SU is associated with a more rapid progression to SUD in adolescence and examines the role of concurrent other SU. Such information can enhance understanding of SUD development in adolescence and may provide crucial data about time periods in which intervention may be promising.

There is little disagreement that early SU onset is associated with an increased risk of SUD. This has been shown for transitions from alcohol use to alcohol disorders (Nelson and Wittchen, 1998a, Brook et al., 2002, Grant and Dawson, 1997, DeWit et al., 2000), from nicotine use to nicotine dependence (Breslau et al., 1993), from cannabis use to cannabis dependence (Chen et al., 2005) and from any illicit SU to illicit SUD (Grant and Dawson, 1998). Animal research has shown tendencies for more intensive SU and for SU in response to distressing events in younger subjects (Siegmund et al., 2005, Füllgrabe et al., 2007, Adriani et al., 2002). While the role of physiological and social factors for the transition to SUD in adolescents with early SU is not clear yet, these subjects may be at risk of more rapid transitions to SUD. Chen et al. (2005) have shown that a younger age of first cannabis use (CU) was associated with an elevated risk of cannabis dependence within the first 24-months after first CU. This may suggest more rapid transitions in those with early CU onset. However, subjects with early onset of alcohol use also had a higher risk of transition to alcohol disorders, but made the transition more slowly (DeWit et al., 2000). Anthony and Petronis (1995) reported similar findings for transition to illicit substance use problems and showed that the elevated risk in early onset users was independent of the time between first use and disorder onset.

Differences between substances concerning the speed of transition from use to dependence, and from abuse to dependence, have been found in studies with subjects from the community (Wagner and Anthony, 2002) and from partially clinical samples (Ridenour et al., 2005). However, these studies do not exclusively cover adolescence and young adulthood and provide little information about transition from use to abuse and transitions to nicotine dependence. Differences between substances in speed of transition from use to dependence were evident in an adolescent sample consisting of largely males and offspring of parents with SUD (Ridenour et al., 2006). With this background and also with consideration of differences in drug policies between countries, it is pertinent to investigate these issues in a representative community sample from Germany.

This present study investigates the speed of transition from first SU to abuse, and from first SU to dependence, for alcohol, cannabis, and nicotine using 10-year prospective-longitudinal data from a representative community sample from Germany. We also investigate the relation between age of onset of SU and the risk and speed of transition to SUD, taking into account concurrent other SU. The aims of the present study were:

• to examine the transition time from first use to SUD for nicotine, alcohol and cannabis in adolescence;

• to assess whether early use in adolescence is associated with a higher risk of transition, and shorter transition time, to abuse or dependence;

• to assess whether concurrent use of other substances is associated with the risk and speed of transition.