Suicidal Ideation Severity and Attempt Frequency Prior to Inpatient Psychiatric Hospitalization Among Adolescents Presenting with Varying Levels of Alcohol and Marijuana Use

Background and Purpose: Suicide is the second leading cause of death for youth in the US. Although alcohol use elevates risk for suicide attempts among adolescents, there is mixed evidence for marijuana use as a risk factor for suicide. In addition, the nuanced relationship between suicidal ideation, suicide attempts, and varying levels of alcohol and marijuana use among adolescents is not well understood. The population with greatest acuity of these behaviors, and thus greatest risk for suicide death, are psychiatrically hospitalized adolescents following a suicidal event. This study examines whether the severity of suicidal ideation and number of suicide attempts three months prior to inpatient psychiatric hospitalization differed among adolescents with varying levels of alcohol and marijuana use.

Methods: Participants were recruited from an inpatient psychiatric unit in the northeastern US. This study included 41 adolescents (80.95% female; M_age=15.69) hospitalized following a suicide plan or attempt who endorsed past month alcohol use. Suicidal ideation severity was measured using the Suicide Ideation Questionnaire (SIQ), and past 90-day marijuana use, alcohol use, marijuana quantity, alcohol quantity, and number of suicide attempts were measured using the Timeline Follow Back Calendar (TLFB). Marijuana quantity (M=33.89, SD=80.19), alcohol quantity (M=35.82, SD=47.42), and suicide attempts (M= 2.58, SD=10.16; No Attempts=26.8%, One or more attempts=73.2%) were analyzed as continuous variables encompassing the total amount of alcohol consumed, total days marijuana was used, and total number of suicide attempts made in the previous 90 days. Groups for alcohol use were divided into low-moderate (1-3 days, n=15) and heavy (4-90 days, n=26). Groups for marijuana use were divided into no (0 days, n=9), low-moderate (1-14 days, n=24), or heavy (15-90 days, n=8). One-way between subjects ANOVAs were conducted to compare the effects alcohol and marijuana on baseline SIQ scores and suicide attempt totals.

Results: No effects of alcohol use on SIQ scores for adolescents with low-moderate or heavy alcohol use were found [F(31.38, 6.67)=0.83, p=0.67]. There was a statistically significant effect of marijuana use on SIQ scores for the three conditions [F (34,6)=5.81, p<.05]. Post-hoc comparisons using the Tukey HSD test indicated the mean score for no marijuana use (M=88.78, SD=41.11) was significantly lower than low-moderate (M=100.08, SD=38.57) and heavy (M=119.13, SD=33.89). The low-moderate marijuana use group did not statistically significantly differ from the heavy group. Spearman’s correlations showed a statistically significant relationship between past 90-day quantity of alcohol use and past 90-day suicide attempt frequency (r_s=0.32, p<.05). However, the relationship between past 90-day quantity of marijuana use was not related with past 90-day suicide attempt frequency.

Conclusions and Implications: Findings suggest that for psychiatrically hospitalized suicidal adolescents who drink, more frequent marijuana use is associated with more severe suicide ideation. In addition, more frequent alcohol use is associated with increased risk for suicide attempts, but not suicide ideation severity. Given the significant role alcohol plays in subsequent suicide-related behaviors, and that alcohol and marijuana use commonly co-occur, there is a need to develop and test integrated alcohol, marijuana, and suicide interventions during inpatient psychiatric hospitalization for adolescents.