Table 4. Randomized controlled trials of ACT.
| Study | N | Type Participant | Mean Age | % Male | No. of Treatment Sessions | Control Group(s) | Main Outcome |
|---|---|---|---|---|---|---|---|
| Zettle & Hayes, 1986 | 18 | Depressed patients | NR | 0 | 12 weeks | CT (12) | ACT > CT: reductions in depression & believability of thoughts; Tx = CT; frequency of automatic thoughts |
| Zettle & Rains, 1989 | 31 | Depressed patients | 41 | 0 | 12 weeks | CCT (10) PCT (10) | ACT = CCT = PCT: reduction in depression; ACT < CCT & PCT: reduction in dysfunctional attitudes |
| Bond & Bunce, 2000 | 90 | Volunteers of a media organization | 36 | 50 | 3 9-hr sessions | IPP (30) WL (30) | ACT = IPP > WL: reduction in depression & increase in propensity to innovate |
| Bach & Hayes, 2002 | 80 | Psychiatric inpatients with psychotic symptoms | 39 | 64 | 4 45-50-min sessions | TAU (40) | ACT > TAU: improvement in symptom reporting, reductions in symptom believability & rates of hospitalization |
| Zettle, 2003 | 24 | College students | 31 | 17 | 6 weeks | SD (12) | ACT = SD: reductions in math & test anxiety; ACT < SD: reduction in trait anxiety |
| Gifford et al., 2004 | 76 | Nicotine-dependent smokers | 43 | 41 | 7 weeks | NRT (43) | ACT = NRT: average number of cigarettes smoked & quit rates |
| Hayes et al., 2004 | 124 | Polysubstance-abusing Opiate Addicts | 42 | 49 | 16 weeks | MM (38) ITSF (44) | ACT = ITSF > MM: reductions in opiate & drug use (at follow up); ACT = ITSF = MM: reduction in distress & improvement in adjustment |
| Woods et al., 2006 | 25 | Patients with trichotillomania | 35 | 8 | 12 weeks | WL (13) | ACT > WL: reductions in hair pulling severity, impairment, & amount of hair pulled |
| Gaudiano & Herbert, 2006 | 40 | Psychiatric inpatients with psychotic symptoms | 40 | 64 | 3 sessions (average) | ETAU (21) | ACT > ETAU: reductions in affective symptoms, social impairment, & hallucination-associated distress |
| Lappalainen et al., 2007 | 28 | Outpatients (mixed symptoms/ diagnoses) | 42 | 11 | 10 sessions | CBT (14) | ACT > CBT: reduced depression, improved social functioning |
| Forman et al., 2007 | 99 | Outpatients (mixed symptoms/ diagnoses) | 28 | 20 | 15-16 sessions (average) | CT (44) | ACT = CT: reductions in depression & anxiety, improvements in quality of life, life satisfaction, & general functioning |
Notes. NR = Not Reported; CT = Cognitive Therapy; CCT = Complete Cognitive Therapy; PCT = Partial Cognitive Therapy; WL = Waitlist; TAU = Treatment As Usual; SD = Systematic Desensitization; NRT = Nicotine Replacement Therapy; MM = Methodone Alone; ITSF = Intensive Twelve Step Facilitation Therapy Plus Methodone Maintenance; ETAU = Enhanced Treatment As Usual.