INTRODUCTION. One of the main problems of the treatment of cocaine-dependent patients is the high rate of relapses occurs within the first months after detoxification. In the early withdrawal phase, patients suffer severe anxious depressive symptoms, known in the argot as crash, which occurs in parallel with an appetite overflowed by re-experiencing the effects of the substance, known as craving. Most of the times, these clinical symptoms act as negative reinforcement, which can be severe enough to induce a drug-relapse that greatly hampers the treatment.

TYPE OF STUDY randomized, double-blind, placebo-experimental. GENERAL PURPOSE To determine the efficacy of mirtazapine for the treatment of cocaine dependence. SPECIFIC OBJECTIVES 1) To evaluate the efficacy in the treatment of craving in individuals with cocaine dependence disorder treated with mirtazapine during acute withdrawal phase. 2) Determine the efficacy of reducing anxious depressive symptomatology (Crash) associated with acute withdrawal in subjects with cocaine dependence disorder treated with mirtazapine. 3) Evaluate the maintenance of abstinence in patients with cocaine dependence disorder treated with mirtazapine. 4) Determine the efficacy of mirtazapine in the treatment of subjects dependent on cocaine comorbid with major depressive disorder.

HYPOTHESIS For pharmacokinetics and pharmacodynamics mirtazapine contribute to the reduction in the intensity of withdrawal symptoms in cocaine dependent subjects by acting on the neurochemical circuitry involved in the reward-seeking behavior and has a prolonged effect anticraving. METHOD The attending physician outpatient identifies the Addiction Clinic of the National Institute of Psychiatry who meet the inclusion criteria and invite them to participate voluntarily. If patients accept, send them to the principal investigator for the start of the ratings. Demographics INSTRUMENTS, MINI structured interview, Anxiety and Depression Scale Beck Scale.

Evaluation. Evaluation of cocaine craving was assessed weekly through the Cocaine Craving Questionnaire (CCQ-G) (43-46). The CCQ-G measures the desire or urge level for drug consumption throughout the 45 Likert items established in the Questionnaire. The Likert scale consisted of seven options ranging from 1 to 7. Indicating from the lowest number (1) complete disagree of questions asked/item and the highest number (7) complete agreement of questions answered/item. CCQ-G items were written in past tense, with the intention that participants could report their cocaine craving status (level) during the previous week. Main items in the CCQ-G used to assess cocaine craving defined as factors were; a). Elements that denote intense cocaine craving (factor 1); b). Items that related to the anticipation of positive results (factor 2); c). Anticipation of relief from drug-withdrawal symptoms (factor 3); and d). Items that perceived a lack of control over cocaine consumption, denoting the intention and planning for cocaine consumption (factor 4).

Each week patient were assessed about their psychopathological status through the Symptom Check List 90 (SCL-90-R) (47-50). The SCL-90 evaluate the psychological degree of "distress" shown by a subject through 90 Likert-type reagents, ranging from 0 up to 4, and grouped into nine dimensions, which include, somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation and psychoticism.

Statistical Analysis.

Data were expressed, as mean ± SEM. To determinate the differences in score between groups over time, the data were then analyzed by a two-way repeated measures ANOVA with time (week) as the repeated measure. If there was a significant interaction between time and treatment, we then performed a Tukey's post-hoc test to detect significant differences between each one of the factors at each experimental phase. Comparisons between mean score obtained during each phase were analyzed by a two-way ANOVA (treatment x phase) followed by Tukey's test for post-hoc comparisons. The level of statistical significance was set at p < 0.05.

Inclusion Criteria:

Who can read and write. Meet the DSM IV TR criteria for substance dependence disorder (Snuff, cocaine, ethanol and polysubstance.). That meet the ratings.

Exclusion Criteria:

disorder subjects with a history of dependency that are not abstinent (³. 1 month). Subjects with a history of neurological diseases. Subjects with general medical illness (eg CVD, hypertension, DM). Subjects prior to the implementation of neurocognitive testing report having consumed coffee, tea, alcohol or smoked three hours conducting assessments. Subjects who take more than 3 prescription drugs. Those who report being too tired. Subjects who report not having made an effort to answer the tests.