Many molecular mechanisms are involved in the reward system of the brain. Natural rewards include food, mating and socialization. Artificial rewards include psychostimulative substances, such as methamphetamine (METH). Dopaminergic reward system of fruit fly in Drosophila melanogaster can be stimulated by both natural and artificial rewards. Reward system in D. melanogaster is mainly regulated by signal molecules dopamine (DA) and neuropeptide F (NPF) signalling. Positive social experiences are rewarding and increase the levels of DA and NPF in D. melanogaster. Sexual deprivation in D. melanogaster has led to an increased preference for ethanol and is explained through the mechanism of NPF signalling. Negative social experiences lead to increased aggression, lack of sleep, disturbed food intake and mating. It causes many epigenetic changes with the emphasis on DNA methylation. Social isolation increases the preference for psychostimulative substances in many species and in flies an increase in preference to ethanol post social isolation was discovered so far. The aim of this thesis is to analyse the effect of different social experiences on the preferential consumption of METH in D. melanogaster. I analysed the effect of isolation/grouping and its duration, as well as, sexual deprivation, which has not yet been done in D. melanogaster. I included four different groups of flies – isolated mated and virgin and grouped mated and virgin. The FlyCafe experiment allowed the self – administration of METH over the three days of the experiment. Isolated flies show higher METH preference and the preference decreases as the duration of isolation increases. Group housed flies show aversion to METH and this aversion increases with the duration of grouping. Social isolation shows the dominant effect on preference compared to sexual deprivation. The highest change in preference, with regards to duration of isolation/grouping, is present in group housed and mated flies. It indicates the importance of the mating duration in regards to the peak mating capacity in flies. Future experiments should analyse the long-lasting effects of social isolation and sexual deprivation on preferential consumption of METH, to more precisely define environmental effect on the motivation for METH consumption.