The natural course of cannabis use, abuse and dependence during the first decades of life.

AIMS: There has been little available information on the long-term natural course, persistence and remission of cannabis use, abuse and dependence. The current study estimated rates and risk factors associated with stability and variation in cannabis use patterns, cannabis abuse and cannabis dependence in a community sample over a 10-year period. DESIGN, SETTING AND PARTICIPANTS: Prospective longitudinal, epidemiological study with a 4- and 10-year follow-up of a community sample (n = 3021) aged 14-24 years at baseline in Munich, Germany. MEASUREMENTS: Cannabis use, abuse and dependence and associated risk factors were assessed by face-to-face interviews using the Munich Composite International Diagnostic Interview. Findings At baseline, one-third of the sample (34.2%) had used cannabis at least once. The cumulative incidence of cannabis use 10 years later was 50.7%. Fifty-six per cent of all repeated users (five times or more) at baseline reported cannabis use at 4-year follow-up. Ten years later, this proportion had decreased slightly to only 46.3%. Repeated (five times or more) users were almost three times more likely to report repeated use at 10-year follow up (OR = 2.8, 95% CI = 1.6-4.7), compared with those who had used cannabis fewer times. Peer use of cannabis, life-events and alcohol dependence also predicted use of cannabis at 10-year follow-up. CONCLUSIONS: Among youth who have used cannabis repeatedly (five times or more) cannabis use is fairly stable and rates of remission relatively low until age 34 years. Patterns of progression suggest that early targeted preventive measures should delay first use and reduce the number of experiences using cannabis, as these factors appear critical in progression to persistent cannabis use and cannabis dependence.

Social anxiety disorder above and below the diagnostic threshold: prevalence, comorbidity and impairment in the general population.

BACKGROUND: There is a lack of data systematically describing subthreshold expressions of social anxiety disorder (SAD) with regard to prevalence, comorbidity, and impairment. METHODS: This analysis was based on data from the German Health Survey (GHS) and its Mental Health Supplement (GHS-MHS). Social anxiety disorder and its syndromes as well as other mental disorders were assessed with a standardized diagnostic interview (M-CIDI) in 4,174 adults. RESULTS: The 12-month prevalence rate for threshold SAD was 2.0%, subthreshold and symptomatic social anxiety (one DSM-IV criterion missing/two or more criteria missing) was found in 3.0 and 7.5% of the participants, respectively. As expected, threshold SAD was characterized by an elevated risk for comorbid disorders and associated with impairment in diverse areas of life. However, this was also true for the two subthreshold expressions of social anxiety, which were also significantly associated with higher comorbidity and greater impairment compared to the control group. CONCLUSIONS: Our results suggest that social anxiety below the diagnostic threshold is clearly associated with adverse outcomes. Prospective designs should examine the exact temporal and possible causal pathways of this burden in order to inform prevention and early intervention programs.