Clinical characteristics of bipolar disorder groups
| Characteristic | Bipolar disorder and lifetime cannabis use n = 40 | Bipolar disorder and no history of cannabis use n = 31 | Test statistic | p value | Effect size |
|---|---|---|---|---|---|
| Bipolar disorder characteristics | |||||
| Bipolar disorder I | 16 (40.0) | 8 (25.8) | χ2 = 2.12 | 0.35 | V = 0.17 |
| Bipolar disorder II | 13 (32.5) | 10 (32.3) | |||
| Bipolar disorder NOS | 11 (27.5) | 13 (41.9) | |||
| Age at onset | 15.22 ± 2.53 | 14.32 ± 2.91 | U = 468.0 | 0.12 | d = 0.33 |
| Clinical characteristics | |||||
| Lifetime psychosis | 3 (7.5) | 6 (19.4) | χ2 = 2.22 | 0.14 | V = 0.18 |
| Lifetime suicide attempt(s) | 10 (25.0) | 1 (3.2) | χ2 = 6.32 | 0.01† | V = 0.30 |
| Lifetime self-injurious behaviour | 19 (47.5) | 16 (51.6) | χ2 = 0.19 | 0.73 | V = 0.04 |
| Lifetime suicidal ideation | 23 (57.5) | 19 (61.3) | χ2 = 0.10 | 0.75 | V = 0.04 |
| Police contact or arrest | 12 (30.0) | 3 (9.7) | χ2 = 4.33 | 0.04† | V = 0.25 |
| Lifetime physical or sexual abuse | 2 (5.0) | 2 (6.5) | χ2 = 0.07 | 0.79 | V = 0.03 |
| Lifetime psychiatric hospitalization | 21 (52.5) | 11 (35.5) | χ2 = 2.04 | 0.15 | V = 0.17 |
| Current depression score* | 15.83 ± 11.91 | 15.42 ± 9.58 | U = 597.0 | 0.79 | d = 0.04 |
| Lifetime depression score* | 30.40 ± 12.27 | 28.42 ± 11.39 | U = 569.0 | 0.55 | d = 0.17 |
| Current mania score* | 9.45 ± 10.73 | 8.65 ± 8.25 | U = 629.0 | 0.92 | d = 0.08 |
| Lifetime mania score* | 30.25 ± 10.91 | 30.32 ± 9.48 | t = −0.03 | 0.98 | d = 0.01 |
| Lifetime comorbid diagnoses | |||||
| Attention-deficit/hyperactivity disorder | 20 (50.0) | 15 (48.4) | χ2 = 0.02 | 0.89 | V = 0.02 |
| Any anxiety | 30 (75.0) | 24 (77.4) | χ2 = 0.06 | 0.81 | V = 0.03 |
| Substance use disorder | 14 (35.0) | 2 (6.5) | χ2 = 8.15 | 0.004† | V = 0.34 |
| Oppositional defiant disorder | 13 (32.5) | 7 (22.6) | χ2 = 0.85 | 0.36 | V = 0.11 |
| Conduct disorder | 3 (7.5) | 0 | χ2 = 2.43 | 0.12 | V = 0.19 |
| Nicotine use | 9 (22.5) | 2 (6.5) | χ2 = 3.44 | 0.06 | V = 0.22 |
| Alcohol abuse | 4 (10.0) | 1 (3.2) | χ2 = 1.22 | 0.27 | V = 0.13 |
| Alcohol dependence | 5 (12.5) | 0 | χ2 = 4.17 | 0.04† | V = 0.24 |
| Family psychiatric history | |||||
| Mania/hypomania | 6 (15) | 8 (25.8) | χ2 = 1.46 | 0.23 | V = 0.14 |
| Depression | 23 (57.5) | 17 (54.8) | χ2 = 0.01 | 0.94 | V = 0.01 |
| Anxiety | 22 (55.0) | 14 (45.2) | χ2 = 0.48 | 0.49 | V = 0.08 |
| Attention-deficit/hyperactivity disorder | 11 (27.5) | 7 (22.6) | χ2 = 0.16 | 0.69 | V = 0.05 |
| Lifetime medications | |||||
| Second-generation antipsychotic | 29 (72.5) | 24 (77.4) | χ2 = 0.22 | 0.64 | V = 0.06 |
| Lithium | 9 (22.5) | 7 (22.6) | χ2 = 0.00 | 0.99 | V = 0.001 |
| SSRI antidepressant | 14 (35.0) | 9 (29.0) | χ2 = 0.28 | 0.59 | V = 0.06 |
| Non-SSRI antidepressant | 8 (20.0) | 5 (16.1) | χ2 = 0.18 | 0.68 | V = 0.05 |
| Stimulant | 7 (17.5) | 9 (29.0) | χ2 = 1.33 | 0.25 | V = 0.14 |
| Current medications | |||||
| Second-generation antipsychotic | 25 (62.5) | 17 (54.8) | χ2 = 0.42 | 0.51 | V = 0.08 |
| Lithium | 6 (15.0) | 6 (19.4) | χ2 = 0.24 | 0.63 | V = 0.06 |
| SSRI antidepressant | 3 (7.5) | 2 (6.5) | χ2 = 0.03 | 0.86 | V = 0.02 |
| Non-SSRI antidepressant | 1 (2.5) | 2 (6.5) | χ2 = 0.67 | 0.41 | V = 0.10 |
| Stimulant | 2 (5.0) | 3 (9.7) | χ2 = 0.58 | 0.45 | V = 0.09 |