تاثیر اختلالات مصرف کانابیس همبود در تظاهرات بالینی اختلال اضطراب اجتماعی

Abstract Previous research has examined the relationship between social anxiety disorder (SAD) and substance use disorders. Cannabis use disorders (CUDs) are becoming increasingly problematic within the population of individuals with SAD, yet the nature of this comorbidity remains largely unexamined. The aim of the current study from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project was to examine differences between outpatients with SAD with versus without comorbid CUDs. The current study included 873 outpatients with a current diagnosis of SAD. Patients with SAD and comorbid CUDs (n = 173) were then compared to those with SAD without CUDs (n = 700) on demographic and clinical characteristics. Compared to patients without the comorbidity, patients with comorbid SAD and CUDs were more likely to have a lifetime diagnosis of PTSD and specific phobia and lifetime substance use disorders (including alcohol). SAD patients with comorbid CUDs were also more likely to report better physical health, and fewer limitations related to their physical health. These analyses remained significant after controlling for gender, the presence of other substance use disorders, mood disorders, and other anxiety disorders. Findings of this study suggest that there may be a unique relationship between SAD and CUDs that can potentially impact the clinical presentation of individuals with SAD. Future research is needed to examine the impact of this comorbidity in other patient populations.

1. Introduction Social anxiety disorder (SAD) is characterized by the marked and persistent fear of social or performance situations in which embarrassment may occur (American Psychiatric Association, 2000). It is estimated that SAD affects up to 13% of the general population, thereby representing one of the four most prevalent psychological disorders in the United States (Kushner et al., 1990 and Kessler et al., 2005). SAD is associated with impairment in multiple domains including education, romantic relationships, friendships, employment, and daily activities (Schneier et al., 1994). Individuals with SAD report dissatisfaction in a broad spectrum of areas including family life, friends, leisure activities, and income, and also are more likely to rate themselves as globally “low functioning” compared to individuals without SAD (Stein and Kean, 2000). To compound the already pervasive impairment associated with SAD, the course of the disorder tends to be chronic and unremitting, and is characterized by a mean age of onset of 11 years (Judd, 1994 and Dalrymple and Zimmerman, 2008). SAD is significantly associated with the co-existence of substance use disorders. Swendsen et al. (2009) found that in a nationally representative sample, SAD also was significantly associated with the onset of drug dependence and also was a significant predictor of the onset of drug use among baseline non-users. The largest body of research examining comorbid SAD and substance use disorders focuses on alcohol use disorders (AUDs). For individuals with a lifetime diagnosis of SAD, 48% also met criteria for a lifetime diagnosis of AUD and 13.1% met criteria for an AUD within the past 12 months compared to the 12-month prevalence rate of 8.5% in the general population (Grant et al., 2005). SAD patients with comorbid AUDs report more severe social anxiety, poorer psychosocial functioning, greater health problems, greater healthcare utilization, greater interpersonal stress, and a greater number of other psychiatric diagnoses compared to individuals with SAD without a comorbid AUD (Buckner et al., 2008). AUDs with comorbid SAD are associated with more severe symptoms of alcoholism compared to individuals with AUDs without a comorbid SAD diagnosis (Thomas et al., 1999). Although prior research has focused on the relationship between SAD and AUDs, cannabis use disorders (CUDs) within the SAD population are less frequently examined. This is problematic as cannabis dependence is the third most prevalent substance use disorder within the general population after AUDs and nicotine dependence (Anthony et al., 1994). Rates of marijuana use have increased significantly over the course of the past several decades and cannabis currently is the most widely used illicit drug in the world (Murray et al., 2007). Regular marijuana use is associated with a broad range of problems including greater impairment in physical health and increased risk for automobile accident (Sherrill et al., 1991 and Ramaekers et al., 2000). Marijuana use also is prospectively associated with legal problems and academic underperformance (Reilly et al., 1998, Fergusson et al., 2003 and Horwood et al., 2010). The lifetime prevalence of SAD in the general population is as high as 13%, yet within the population of individuals with cannabis dependence, this prevalence rate increases to 29% (Kessler et al., 2005; Agosti et al., 2002). Data from the National Comorbidity Survey (NCS) indicates that SAD (regardless of sub-type) had the strongest association with cannabis dependence out of any anxiety disorder (Agosti et al., 2002). Within a community sample, SAD at study entry was associated with 6.5 greater odds of cannabis dependence (Buckner et al., 2006b). Significant associations between problematic cannabis use and SAD also have been found in college student samples (Buckner et al., 2007; Buckner and Schmidt, 2008, Buckner and Schmidt, 2009a, Buckner and Schmidt, 2009b and Buckner et al., 2011). SAD specifically is correlated with cannabis dependence at rates significantly greater than any other anxiety disorder, indicating that SAD may serve as a specific risk factor for cannabis use disorders (Buckner et al., 2006b). Research has begun to examine the relationship between CUDs and SAD and the impact of such co-existence. For example, daily cannabis users have reported significantly higher scores on social anxiety than individuals who use cannabis less regularly (Oyefeso, 1991). College students with greater social anxiety symptomatology and elevated social fear also indicated greater marijuana use problems (Buckner et al., 2006a, Buckner et al., 2006b and Buckner et al., 2007). A greater understanding of the relationship between problematic cannabis use and SAD also may be important given findings that SAD comorbid with substance use disorders in general is associated with a poorer prognosis, course, and treatment outcome compared to individuals with each disorder separately (Bruce et al., 2005 and Driessen et al., 2001). The goal of the current study from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) Project is to examine the relationship between SAD and CUDs by comparing outpatients who meet criteria for SAD and comorbid CUDs (cannabis abuse and/or cannabis dependence) to those who meet criteria for SAD without CUDs. To our knowledge, this is one of the first studies that examines the impact of this specific comorbidity within a clinical sample, as research on SAD–CUD comorbidity thus far has been conducted almost exclusively on epidemiological and college student samples. Drawing on past research relating problematic cannabis use to Axis I disorders, it was hypothesized that psychiatric outpatients with SAD and comorbid CUDs would have a greater number of other current and lifetime Axis I diagnoses. Problematic cannabis use and CUDs have been linked to higher rates of other anxiety disorders and mood disorders (especially Major Depressive Disorder and bipolar disorder) as well as impulsivity and risky behavior (Crippa et al., 2009, Henquet et al., 2006 and Agosti et al., 2002; van Laar et al., 2007; Kashdan and Hofmann, 2008 and Innamorati et al., 2008). Related to our hypotheses regarding the higher comorbidity rates of Axis I disorders among patients with the SAD–CUD comorbidity, we also hypothesized that these patients would report more time of out of work in the past 5 years due to psychiatric reasons and lower overall functioning. It was predicted that compared to outpatients without this comorbidity, outpatients with comorbid SAD–CUD would endorse poorer physical health (Sherrill et al., 1991; Hathaway, 2008). Buckner et al. (2011) found that social avoidance was significantly associated with marijuana use problems, therefore it was hypothesized that patients with SAD–CUD would report poorer adolescent and current psychosocial functioning compared to SAD patients without CUD. Due to the relatively young age of onset of SAD (Dalrymple and Zimmerman, 2008), it also was predicted that SAD would have a lower mean age of onset than CUD in patients with this comorbidity. Based on results from Zvolensky et al. (2006) that found an earlier age of onset of anxiety (specifically of panic attacks) among individuals who also used cannabis regularly, it also was hypothesized that patients with comorbid SAD and CUD would have a significantly lower mean age of onset for SAD compared to SAD patients without CUD.

Results 3.1. Demographic Correlates SAD patients with comorbid CUD were more likely to be male than female and were significantly younger at the time of clinical presentation compared to SAD patients without CUD (see Table 1). There was no significant difference between SAD patients with and without CUD in terms of marital status or race. Within the group with the SAD–CUD comorbidity, individuals were more likely to have an onset of SAD prior to CUD (61% versus 39%). The mean age of onset for all outpatients who met criteria for current SAD was 12 years (SD = 8.3) and the mean age of onset for CUDs was 16 years (SD = 6.7). 3.2. Clinical Correlates Results from the ANCOVAs on other clinical characteristics (controlling for gender, comorbid other substance use disorders, mood disorders, and other anxiety disorders) showed that patients with comorbid SAD and CUD reported significantly better physical functioning as assessed by the SF-36 and reported significantly fewer limitations from physical functioning, as manifested by higher scores on both subscales (see Table 2). There was no significant difference between the two groups in terms of GAF, time out of work for psychiatric reasons, or age of onset for SAD. Table 2. Clinical correlates of social anxiety disorder patients with versus without a comorbid cannabis use disorder. Clinical correlates SAD–CUD SAD without CUD F p-value Cohen’s d Mean (SD) Mean (SD) Psychosocial functioning Adolescent 3.09 (1.06) 3.33 (1.04) 4.727 0.030 0.22 Current 3.37 (1.32) 3.47 (0.05) 4.744 0.030 0.11 SF-36 health Physical functioning 82.71 (22.48) 75.33 (28.11) 7.537 .006a 0.29 Limitations due to physical healtha 67.86 (40.24) 58.29 (44.34) 6.843 .009a 0.23 Limitations due to emotional problems 24.76 (36.11) 23.35 (34.62) 0.370 0.543 0.04 Energy/fatigue 29.19 (19.66) 26.93 (20.52) 1.041 0.308 0.11 Emotional well-being 31.81 (17.55) 32.45 (19.05) 0.130 0.719 0.03 Social functioning 39.85 (24.79) 38.29 (24.98) 3.003 0.084 0.06 Pain 66.05 (25.24) 65.37 (28.69) 0.323 0.570 0.03 General health 55.20 (21.96) 56.03 (24.13) 0.000 0.996 0.04 GAF 49.13 (9.52) 50.31 (8.66) 0.036 0.850 0.13 Age of onset of SAD 12.03 (8.47) 2.07 (8.47) 0.495 0.482 0.00 Time out of work 2.77 (2.00) 2.90 (2.16) 3.063 0.080 0.06 Note: GAF = global assessment of functioning. a Higher scores on this subscale indicate fewer limitations due to physical health. Table options Patients with the SAD–CUD comorbidity were more likely to have a lifetime substance use disorder (alcohol use disorders and other drug use disorders) compared to individuals without this comorbidity, and this remained significant after controlling for the presence of other anxiety disorders, mood disorders, and gender(see Tables 3 and 4). In addition, the data in Table 3 show that patients with SAD and CUD were more likely to have a lifetime diagnosis of specific phobia and post-traumatic stress disorder (PTSD) compared to patients without this comorbidity. Table 3. Lifetime DSM-IV axis I disorders in psychiatric outpatients with social anxiety disorder with versus without comorbid cannabis use disorders. SAD–CUD SAD without CUD OR CI p-level (n = 173) (n = 700) Mood disorders, % (n): Major depression 65.3 (113) 73.3 (513) 0.6 1.1–2.2 0.013 Dysthymic disorder 18.4 (32) 13.9 (97) 0.2 0.8–2.5 0.237 Depressive disorder NOS 5.2 (9) 8.0 (56) 0.1 0.8–5.0 0.122 Bipolar disorder 20.2 (35) 11.7 (82) 1.8 0.3–0.9 0.018 Anxiety disorders, % (n): Panic disorder 6.4 (11) 6.3 (44) 1.0 0.5–1.9 0.896 Panic disorder w/agoraphobia 33.5 (58) 11.4 (80) 1.4 0.5–1.0 0.084 Agoraphobia w/o history of panic 2.3 (4) 1.9 (13) 1.1 0.3–2.9 0.833 Specific phobia 26.0 (45) 18.7 (131) 1.8 0.4–0.8 0.010∗ Post-traumatic stress disorder 36.4 (63) 26.4 (185) 1.7 0.4–0.9 0.010∗ Generalized anxiety disorder 34.7 (60) 28.0 (196) 1.5 0.5–1.0 0.045 Obsessive–compulsive disorder 15.6 (27) 14.0 (98) 1.1 0.5–1.4 0.610 Anxiety disorder NOS 11.6 (20) 16.5 (116) 0.7 0.8–2.2 0.369 Overall anxiety disorders 75.7 (131) 70.4 (493) 1.5 0.4–1.0 0.060 Substance use disorders, % (n): Alcohol abuse/dependence 72.8 (126) 37.3 (261) 4.1 0.2–0.3 0.000∗ Other drug abuse/dependence 81.5 (141) 40.1 (281) 4.0 0.2–0.3 0.000∗ Impulse control disorders, % (n): 33.5 (58) 23.4 (164) 1.3 0.5–2.0 0.896 Eating disorders, % (n) 18.5 (32) 17.1 (120) 1.0 0.6–1.6 0.988 Somatoform disorders, % (n) 13.9 (24) 12.4 (87) 1.1 0.5–1.5 0.708 Note: OR indicates odds ratio; CI, 95% confidence interval; NOS, not otherwise specified; GMC, general medical conduction; n.s., non-significant. ∗ The analysis was significant at a p-value less than or equal to 0.01. Table options Table 4. Current DSM-IV axis I disorders in psychiatric outpatients with social anxiety disorder with versus without comorbid cannabis use disorders. SAD–CUD SAD without CUD OR CI p-level (n = 173) (n = 700) Mood disorders, % (n): Major depression 44.5 (77) 55.7 (390) 0.6 0.4–0.9 0.013 Dysthymic disorder 9.8 (17) 11.6 (81) 0.2 0.4–1.3 0.237 Depressive disorder NOS 3.5 (6) 7.4 (52) 0.5 0.2–1.2 0.122 Bipolar disorder 17.3 (30) 8.9 (62) 1.8 1.1–3.1 0.018 Anxiety disorders, % (n): Panic disorder 4.6 (8) 4.1 (29) 1.2 0.5–3.0 0.580 Panic disorder w/agoraphobia 26.0 (45) 19.9 (139) 1.4 0.9–2.0 0.151 Agoraphobia w/o history of panic 2.3 (4) 1.9 (13) 1.1 0.3–3.8 0.833 Specific phobia 25.4 (44) 17.7 (124) 1.6 1.0–2.5 0.030 Post-traumatic stress disorder 20.8 (36) 17.6 (123) 1.3 0.8–2.1 0.181 Generalized anxiety disorder 34.1 (59) 27.6 (193) 1.5 0.8–2.2 0.048 Obsessive–compulsive disorder 12.1 (21) 11.9 (83) 1.1 0.6–1.8 0.860 Anxiety disorder NOS 9.2 (16) 12.7 (89) 0.8 0.4–1.4 0.499 Overall anxiety disorders 72.3 (125) 72.9 (510) 1.1 0.7–1.7 0.589 Substance use disorders, % (n): Alcohol abuse/dependence 15.6 (27) 8.7 (61) 1.7 0.3–1.0 0.046 Other drug abuse/dependence 5.8 (10) 2.7 (19) 1.8 0.2–1.2 0.149 Impulse control disorders, % (n) 16.8 (29) 13.4 (94) 1.1 0.7–1.8 0.658 Eating disorders, % (n) 9.2 (16) 8.4 (59) 0.8 0.5–1.7 0.830 Somatoform disorders, % (n) 16.8 (29) 13.4 (94) 0.9 0.6–1.8 0.910 Note: OR indicates odds ratio; CI, 95% confidence interval; NOS, not otherwise specified; GMC, general medical conduction; n.s., non-significant.