Table 1.
Cognitive effects of repeated AMPH administration
| Species | Pretreatment regimen |
Test time following pretreatment | Test | Challenge dose? | Results | Study | ||
|---|---|---|---|---|---|---|---|---|
| Dose | Frequency | Duration | ||||||
| Rhesus monkeys | 0.1–1.0 ;mg/kg; i.m.; escalating | Twice daily; weekends off | 6 or 12 ;weeks | >6 ;months | Delayed response; delayed non-match to sample | In selected cases; 0.4 ;mg/kg | Impaired acquisition of delayed response and DMNS; challenges disrupt DR performance | Castner et al. (2005) |
| Rat | 4.0 ;mg/kg; s.c. | Once daily | 5 ;days | Immediately after | Associative blocking/ selective attention | Testing took place on days 4 and 5 of the pretreatment | Blocking effect absent | Crider et al. (1982) |
| Rat | 1.0–5.0 ;mg/kg; i.p. | 3× daily | 6 ;days | Immediately after | Operant sustained attention | On day 7; 1.0 ;mg/kg | Increased false alarm rate; no effects of challenge | Kondrad and Burk (2004) |
| Rat | 1.0–3.0 ;mg/kg; i.p. | 3× per week | 3 or 5 ;weeks | 22 ;days | Prepulse inhibition | No | PPI disruption | Tenn et al. (2003) |
| Rat | 1.0–5.0 ;mg/kg; i.p. | 3× per week | 5 ;weeks | 4 ;weeks | Attentional set shifting | No | Impaired on the extra-dimensional shift and on reversal discriminations | Fletcher et al. (2005) |
| Rat | 1.0–5.0 ;mg/kg; i.p. | 3× per week | 5 ;weeks | Testing took place during 5 ;weeks withdrawal | 5-Choice serial reaction time | No | Persistent increase in omissions reduced response accuracy under reduced stimulus duration | Fletcher et al. (2007) |
| Rat | 1.0– 10.0 ;mg/kg; i.p. escalating | Twice daily; weekends off | 40 ;days | 20 ;days | Operant sustained attention | None, 0.5 or 1.0 ;mg/kg | Decreased hit rate after challenge | Martinez et al. (2005) |
| Rat | 1.0– 10.0 ;mg/kg; i.p. escalating | Twice daily; weekends off | 40 ;days | >50 ;days | Operant sustained attention | None or 1.0 ;mg/kg | Decreased hit and correct rejection rates after challenge | Kozak et al. (2007) |
| Rat | 1.0– 10.0 ;mg/kg; i.p. escalating | Twice daily; weekends off | 40 ;days | 35–55 ;days | Operant sustained attention | None or 1.0 ;mg/kg | Decreased hit and correct rejection rates after challenge; distractor-induced disruption in the absence of challenges | Young et al. (2007) |
| Rat | 1.0– 10.0 ;mg/kg; i.p. escalating | Twice daily; weekends off | 40 ;days | 10–20 ;days | Operant sustained attention | None or 1.0 ;mg/kg | Decreased hit rat after challenge | Martinez and Sarter (2008) |
Data from studies involving neurotoxicity-inducing pretreatment regimen are not listed. Likewise, studies that explicitly addressed the cognitive correlates of psychostimulant withdrawal were not considered for this synopsis (except of studies that generated measures at >4 weeks since completion of the pretreatment regimen).