Depression in Child Increased If Mother Smoked Marijuana in Pregnancy: In a 10-year follow-up of 633 mother-child pairs in the Maternal Health Practices and Child Development Project and using multivariate regressions, marijuana use in the first and third trimesters predicted increased depression in the child at age 10. Other significant correlates of depressive symptoms in the children included lower maternal education, maternal tobacco use (prenatal or current), and the child's lower IQ score. Prenatal marijuana exposure: effect on child depressive symptoms at ten years of age. Gray KA, et al.  National Institute of Environmental Health Sciences. Neurotoxicol Teratol. 2005 May-Jun;27(3):439-48

Depression Higher with Teen Marijuana Use: Cannabis use is very prevalent (25%) in Australia high school survey (13-17yo). The association with depression, conduct problems, excessive drinking and use of other drugs shows a malignant pattern of comorbidity that may lead to negative outcomes. Br J Psychiatry 2002 Mar;180:216-21

Depressed Teens More Marijuana: depressed adolescents also had less optimal peer relationships, fewer friends, and were less popular. They experienced less happiness and more frequent suicidal thoughts. They spent less time doing homework, had a lower grade point average, and spent less time exercising. The depressed group also reported more use of marijuana and cocaine. A stepwise regression indicated that physical affection with parents, homework, well-being, exercise, happiness, and parent relations explained 55% of the variance. Miami survey 79 high school students. Adolescence 2001 Fall;36(143):491-8

Marijuana Causes Depression: 1,920) in the 1980 Baltimore Epidemiologic Catchment Area study who were reassessed between 1994 and 1996 as part of a follow-up study provided the data. The analysis focused on two cohorts: those who reported no depressive symptoms at baseline (N=849) and those with no diagnosis of cannabis abuse at baseline (N=1,837). Symptoms of depression, cannabis abuse, and other psychiatric disorders were assessed with the Diagnostic Interview Schedule. RESULTS: In participants with no baseline depressive symptoms, those with a diagnosis of cannabis abuse at baseline were four times more likely than those with no cannabis abuse diagnosis to have depressive symptoms at the follow-up assessment, after adjusting for age, gender, antisocial symptoms, and other baseline covariates. In particular, these participants were more likely to have experienced suicidal ideation and anhedonia during the follow-up period. Among the participants who had no diagnosis of cannabis abuse at baseline, depressive symptoms at baseline failed to significantly predict cannabis abuse at the follow-up assessment. Am J Psychiatry 2001 Dec;158(12):2033-7

Depressed Teens More Likely Use Marijuana: Seventy of 1340 adolescents (5.2%) met criteria for self-reported depression. Agreement between parent- and adolescent-reported depression was poor. Adolescent-reported depression was associated with increased suicide plans (odds ratio [OR], 2.83) and attempts (OR, 9.05) in the previous year, use of marijuana 10 or more times in the previous month (OR, 2.88), having conduct disorder (OR, 4.09). Three per cent (2/70) of depressed adolescents had been treated with antidepressants. Rey, Sydney, Aust. Med J Aust 2001 Jul 2;175(1):19-23. Bupropion worsens mood in marijuana withdrawal. Psychopharmacology (Berl) 2001 May;155(2):171-9

Drug Using Teen Much More Depression: 5721 students (59%-63% Hispanic) completed self-report items on depressive symptoms, recent smoking and binge drinking, and lifetime use of marijuana, cocaine, and inhalants. RESULTS: Symptoms of depression were strongly and positively related to substance use. For every type of use, a stepwise increase was seen between the percentage of students with low symptom frequency and the percentage of students with more symptoms. A sizable number of users reported symptoms indicating major depression. Am J Public Health 2001 May;91(5):761-6

Smoking, Marij, Not Depr Leads to Alcohol: Smoking, marijuana use, and conduct problems were consistent promoters of transitions to more severe drinking classes, but depressed affect was not a significant predictor. Parental history of alcohol problems or excessive drinking, particularly maternal history, was a significant predictor. 1799 female twins studied. Bucholz, Wash U. Alcohol Clin Exp Res 2000 Jun;24(6):914-23

Depression Incr with Incr Marijuana: 83% of subjects with DSM-III-R cannabis dependence, 46% of those with DSM-III-R cannabis abuse and 29% of occasional users received at least one DSM-III-R psychiatric diagnosis. The severity of depressive, anxious and alexithymic symptoms increased progressively with the degree of involvement with cannabis. Study of 133 Italian military recruits found to have marijuana on screening urines. Addiction 1998 Apr;93(4):487-92