The End of My Addiction

the Clinician-Administered PTSD Scale (CAPS), and secondary outcome measures included the Hamilton Rating Scale for Anxiety, the Hamilton Rating Scale for Depression, the Global Assessment of Functioning Scale, and the Clinical Global Impressions.
    Results
    In the 11 patients who completed the 8-week trial, the mean total CAPS score decreased significantly from baseline (from 82.9 ± 16.1 to 63.5 ± 21.2). The avoidance and hyperarousal subscales showed significant decreases (from 36.2 ± 6.2 to 26.5 ± 9.6 and from 31.9 ± 6.5 to 22.1 ±7.1, respectively), whereas the re-experiencing subscale remained unchanged. Significant improvements were also noted on all secondary outcome measures. Treatment response was noted within the first 4 weeks of treatment and was maintained throughout the trial. Baclofen therapy was well tolerated, as only 1 patient dropped out due to adverse effects.
    Conclusions
    Baclofen therapy was effective in treating both the PTSD symptoms and accompanying depression and anxiety in patients with chronic PTSD due to combat. Larger, double-blind, placebo-controlled studies are needed to confirm the efficacy of baclofen in the treatment of PTSD.

Baclofen in Animal Studies: Dose-Dependent Effects
    Abstract 1
    Roberts, D. C., and Andrews, M. M. (1997) Baclofen suppression of cocaine self-administration: demonstration using a discrete trials procedure.
    Psychopharmacology (Berlin) 131, 271–277.
    We have previously reported that rats display a circadian pattern of cocaine self-administration if access to drug is limited to 10-min discrete trials that are separated by at least 20 min. In the present study, the pattern of cocaine intake (1.5 mg/kg per injection) was studied in two large groups of animals that were maintained on different 12-h light/dark cycles (3 a.m. to 3 p.m. versus 10 a.m. to 10 p.m.). Regardless of the time of light onset, a circadian pattern of cocaine self-administration was observed. Maximum cocaine intake occurred during the final 6 h of the dark period and was followed by a relative abstinence period during the light phase. This highly predictable pattern of drug taking behavior provided an opportunity to explore the effect of baclofen, a GABA B agonist, on the initiation of self-administration behavior. In two separate studies, acute treatment with baclofen (1.25–5.0 mg/kg) was shown to suppress cocaine intake for at least 4 h. Baclofen had no significant effect on responding for food reinforcement. Previous results have indicated that baclofen appears to reduce specifically the motivation to respond for cocaine. Together, these data suggest that baclofen should be considered as a possible pharmacotherapeutic agent in cocaine addiction.

 
    Abstract 2
    Xi, Z. X., and Stein, E. A. (1999) Baclofen inhibits heroin self-administration behavior and mesolimbic dopamine release.
    The Journal of Pharmacology and Experimental Therapeutics 290, 1369–1374.
    An emerging hypothesis to explain the mechanism of heroin-induced positive reinforcement states that opiates inhibit gamma-aminobutyric acid (GABA)-ergic interneurons within the mesocorticolimbic dopamine (DA) system to disinhibit DA neurons. In support of this hypothesis, we report that the development of heroin self-administration (SA) behavior in drug-naive rats and the maintenance of SA behavior in heroin-trained rats were both suppressed when the GABA B receptor agonist baclofen was coadministered with heroin. Microinjections of baclofen into the ventral tegmental area (VTA), but not the nucleus accumbens, decreased heroin reinforcement as indicated by a compensatory increase in SA behavior. Additionally, baclofen administered alone or along with heroin dose-dependently reduced heroin-induced DA release. This effect was blocked partially by intra-VTA infusion of the GABA B antagonist 2-hydroxysaclofen, suggesting an additional, perhaps GABA A receptor-mediated, disinhibitory effect. Taken together, these experiments, for the first time, demonstrate that heroin-reinforced SA behavior and nucleus accumbens DA release are mediated predominantly by GABA B receptors in the VTA and suggest that baclofen may be an effective agent in the treatment of opiate abuse.

 
    Abstract 3
    Colombo, G., Vacca, G., Serra, S., et al. (2003) Baclofen suppresses motivation to consume alcohol in rats.
    Psychopharmacology (Berlin) 167, 221–224.
    Rationale
    Recent studies demonstrated that treatment with the gamma-aminobutyric acid (GABA B )