Individuals who report psychotic-like experiences (PLEs) are at significantly increased risk for clinical psychotic disorders. However, associations between PLEs and non-psychotic disorders indicate that the clinical relevance of PLEs is not limited to psychosis and thus, investigating the role of additional symptoms, such as depression, may improve the capacity to predict risk of developing psychotic disorders. Additionally, studying theory of mind (ToM) abilities, one of the cognitive areas impaired in schizophrenic patients, in adolescents from the general population may contribute to clarify whether ToM deficits are present in at-risk individuals before the onset of the illness and derived impairments. Evidence suggests that ToM impairments are not exclusive of symptomatic patients, and that further understanding of the nature of ToM dysfunction in schizophrenia might be achieved through examination of ToM impairments from the early phases and even before the onset of the illness. Objectives: this thesis was aimed at (1) examining the presence of both positive and negative PLEs and their association with depressive symptoms in a community sample of adolescents; (2) analysing the presence of subtypes of positive and negative PLEs dimensions in adolescents of the community, and (3) exploring ToM functioning, its association with psychometric schizotypy, PLEs, and depressive symptoms, in a sample of adolescents from the general population. Method: participants in this cross-sectional study were adolescents aged between 13 and 17 years, attending compulsory secondary education in schools from Barcelona, Spain. To establish the presence of subtypes of positive and negative PLEs, separate principal component factor analyses of the CAPE positive and negative subscales were performed. Multiple linear regression analysis was conducted to examine the association between specific CAPE positive and negative PLE subtypes and depressive symptoms. Results: PLEs and psychometric schizotypy dimensions were present in this community sample of adolescents. Four factors of positive symptoms (persecutory ideation, grandiose thinking, first-rank-hallucinatory, and self-referential thinking) and three factors of negative symptoms (social withdrawal, affective flattening, and avolition) emerged from the analysis. Different relationships between subtypes of positive PLEs and depressive symptoms were found: persecutory ideation and first-rank/hallucinatory experiences related to higher scores on the depressive symptoms scale whilst grandiose thinking related to lower scores on depression. No association with self-referential thinking was found. Associations between subtypes of the negative dimension and depression were also found: social withdrawal and avolition were positively associated with the self-report of depressive symptoms, while affective flattening did not relate to depression. No differences were found in ToM abilities in adolescents with higher global scores on schizotypy or PLEs relative to those with lower global scores. Higher scores on the unusual experiences subscale assessing positive schizotypy and on first-rank experiences were associated with poorer ToM ability, whereas persecutory beliefs were related to better ToM performance. No association was found between ToM and magical thinking or hallucinatory experiences. Negative PLEs or negative schizotypy were not related to ToM abilities. In addition, an association between better mentalising abilities and higher impulsive nonconformity was found. Conclusions: these findings support the view that not all types of positive and negative PLEs in adolescence are associated with depression and, therefore, may not confer the same vulnerability for psychotic disorders. ToM impairments are not restricted to the acute phase of a psychotic disorder, and may be associated to positive schizotypy and first-rank experiences. These findings constitute evidence indicating that ToM impairments can be identified during adolescence before the onset of any psychotic disease.