| PMC full text: | Twin Res Hum Genet. Author manuscript; available in PMC 2013 Oct 1. Published in final edited form as: |
TABLE 2
Summary of Domains Assessed
| Cannabis use |
| Age of first use opportunity |
| Age at initiation of cannabis use |
| Initial reactions to cannabis use |
| Weekly use |
| Daily use |
| Cannabis use disorders |
| Abuse (Including age at onset) |
| Dependence (DSM-IV, including withdrawal) |
| Other illicit drug use |
| Age of first use opportunity |
| Lifetime use |
| Age of onset |
| Frequency of use (when used most) |
| Abuse |
| Dependence |
| Tobacco use |
| Initiation of smoking |
| First reactions to tobacco |
| Transition to weekly smoking (age) |
| Transition to daily smoking (age) |
| Current frequency of smoking |
| Current cigarettes/day when smoked |
| Maximum cigarettes in single day |
| Tobacco dependence (DSM-IV) |
| Alcohol use |
| Initiation of alcohol use |
| First reactions to alcohol |
| Frequency of alcohol use |
| Amounts consumed (current and maximum) |
| Alcohol abuse/harmful use (DSM-IV) |
| Alcohol dependence (DSM-IV) |
| Parental alcohol use/problems |
| Proximal risk factors |
| Peer behaviors |
| Perceived peer Smoking |
| Perceived best friend’s smoking |
| Perceived peer alcohol use |
| Perceived best friend’s alcohol use |
| Perceived peer delinquent behavior |
| Perceived peer illicit drug use |
| Perceived co-workers tobacco, alcohol, and illicit drug use |
| Behavioral inhibition |
| Major depression |
| Suicidal ideation |
| Suicide attempt |
| Neuroticism (NEO) |
| Social phobia (DSM) |
| Panic disorder (DSM) |
| Agoraphobia (DSM) |
| Deliberate (nonsuicidal) self harm |
| Behavioral undercontrol |
| Childhood conduct disorder |
| Antisocial personality disorder |
| Childhood hyperactivity |
| Childhood inattention |
| Extraversion (NEO) |
| Novelty seeking (TPQ) |
| Sociodemographic |
| Household income |
| Parental educational levels |
| Parental marital status & history |
| Family structure & rearing history |
| Ethnicity |
| Religious affiliation & involvement |
| Academic achievement |
| School grades |
| Educational history/status |
| Family ‘environment’ variables |
| Perceived parental conflict |
| Perceived parent–child conflict |
| Perceived sibling smoking, alcohol, illicit drug |
| Parent–child relations — parental involvement |
| Parental coldness, overprotection |
| Parental major depression |
| Parental alcohol dependence |
| Parental discipline |
| Risk modifiers |
| Parent–child relations — parental control |