Progesterone Increases Nicotine Withdrawal and Anxiety in Male but Not Female Smokers During Brief Abstinence.

INTRODUCTION: Although exogenous progesterone may hold promise as a treatment for nicotine use disorders, it is unclear whether it is similarly effective in males and females. This study examined the effects of progesterone on nicotine use disorder comprehensively using behavioral, psychological, and neural measures in male and female smokers exposed to brief abstinence. AIMS AND METHODS: Thirty-three male and 33 female non-treatment-seeking smokers participated in a double-blind, randomized, placebo-controlled crossover study of 200 mg of progesterone or placebo daily over a four-day abstinence period. Smoking behavior and subjective effects of nicotine were assessed at baseline and after final drug administration. Nicotine withdrawal, smoking urges, mood states, and neural response to smoking cues were measured at baseline, after the first drug administration, and after the final drug administration. RESULTS: No main effect of drug (progesterone vs. placebo) emerged for any outcome. Significant sex by drug interactions emerged for nicotine withdrawal (p = .020), perceived strength of nicotine (p = .040), and perceived bad effects of nicotine (p = .029). Males receiving progesterone reported worse nicotine withdrawal (p = .046) and a trend towards decreased bad effects of nicotine (p = .070). Males on progesterone also reported greater tension and anxiety relative to placebo (p = .021). Females on progesterone perceived nicotine's effects as being stronger relative to placebo (p = .046). CONCLUSIONS: Progesterone causes sex-dependent effects on smoking-related outcomes during brief abstinence. Specifically, progesterone in males may increase rather than decrease nicotine withdrawal and negative affect during abstinence, potentially hindering efforts to quit smoking. IMPLICATIONS: In male and female smokers undergoing a brief period of abstinence, we examined the effects of progesterone on smoking outcomes. While progesterone had limited effects in female smokers, in males, it worsened nicotine withdrawal and negative affect. Our findings emphasize the importance of analyzing sex differences in future studies examining progesterone as a potential treatment and suggest that progesterone in males could potentially exacerbate aspects of nicotine dependence. CLINICALTRIALS.GOV REGISTRATION: NCT01954966. https://clinicaltrials.gov/ct2/show/NCT01954966.

Effect of progesterone administration in male and female smokers on nicotine withdrawal and neural response to smoking cues: role of progesterone conversion to allopregnanolone.

BACKGROUND: Progesterone administration has therapeutic effects in tobacco use disorder (TUD), with females benefiting more than males. Conversion of progesterone to the neurosteroid allopregnanolone is hypothesized to partly underlie the therapeutic effects of progesterone; however, this has not been investigated clinically. METHODS: Smokers (n = 18 males, n = 21 females) participated in a randomized, double-blind, placebo-controlled crossover study of 200 mg progesterone daily across 4 days of abstinence. The ratio of allopregnanolone:progesterone was analyzed in relationship to nicotine withdrawal, smoking urges, mood states, subjective nicotine effects, and neural response to smoking cues. RESULTS: Allopregnanolone:progesterone ratio interacted with sex to predict withdrawal symptoms (p = 0.047), such that females with higher allopregnanolone:progesterone ratios reported lower withdrawal severity (b = - 0.98 [- 1.95, - 0.01]; p = 0.048). In addition, allopregnanolone:progesterone ratio interacted with sex to predict confusion (p = 0.014) and fatigue (p = 0.034), such that females with higher allopregnanolone:progesterone ratios reported less confusion (b = - 0.45 [- 0.78, - 0.12]; p = 0.008) and marginally lower fatigue (b = - 0.50 [- 1.03, 0.02]; p = 0.062. Irrespective of sex, higher ratios of allopregnanolone:progesterone were associated with stronger "good effects" of nicotine (b = 8.39 [2.58, 14.20]); p = 0.005) and weaker "bad effects" of nicotine (b = - 7.13 [- 13.53, - 0.73]; p = 0.029). CONCLUSIONS: Conversion of progesterone to allopregnanolone correlated with smoking-related outcomes in both sex-dependent and sex-independent ways. Sex-dependent effects suggest that conversion of progesterone to allopregnanolone may contribute to greater therapeutic benefits in females but not males with TUD. Trial registration Clinicaltrials.gov registration, retrospectively registered: NCT01954966; https://clinicaltrials.gov/ct2/show/NCT01954966 \.