Abstract

The aim of this doctoral thesis is to present methods of search, evaluation and analysis of a specific research domain (schizophrenia) from four perspectives: bibliometric analysis of 1) Finnish doctoral theses and 2) Finnish journal articles on schizophrenia, and meta-analysis to determine the prevalence of 3) alcohol use disorders and 4) cannabis use disorders in schizophrenia.

Over the years, the number of Finnish articles on schizophrenia has increased, as well as the amount of international collaboration. Bibliometric methods were also found to be feasible in the evaluation of psychiatric research. However, the methods should be used with care. Articles written in collaboration with international organisations seem to receive more citations and are published in journals with higher impact factors, which highlights the importance of developing scientific networks. A considerable proportion (20%) of Finnish scientific schizophrenia articles were published in theses consisting of original papers. The current funding system supports the writing of doctoral thesis consisting of original articles and favours epidemiological and biological research over research into medical treatments. This may affect the research culture in Finland and even slow down the development and improvement of the national treatment system.

The reported prevalence of alcohol and cannabis use disorders has differed considerably between studies. No meta-analysis on alcohol or cannabis use disorders in schizophrenia has previously been conducted. In studies (n = 71) on schizophrenia patients, the median prevalence was 15% for current and 26% for lifetime alcohol use disorder, and 16% for current and 27% for lifetime cannabis use disorder. Alcohol use disorders are common in schizophrenia patients, although a declining trend was observed when comparing previous reviews. Cannabis use disorders were found to be more common in younger and first-episode patient samples, as well as in samples with a high proportion of males.