Depression and substance use disorders are common cooccurring conditions in all populations and young people in colleges are not an exception. Sometimes depression has been found to be the precursor of substance use. The aim of this study is to find out the relationship between levels of Depression and Substance Use among students of tertiary institutions in Taita Taveta County, Kenya. The study shallfocus on depression levels and its relationship with substance use. The study is a correlational research design. All the respondents from the four participating tertiary institutions shall be assessed using both Beck’s Depression Inventory andthe Alcohol, Smoking and Substance Involvement Screening Test (ASSIST).The study will be carried out in selected four tertiary institutions. The study will use a sample of 281 students from the selected institutions. Data will be collected using questionnaires, BDI depression standardized tool and Key Informant Interviews Questionnaires for Principals, Deans of Students and Tutors in charge of counseling programs. The reliability of data collection instruments will be tested using the Cronbach’s alpha. The captured data will be entered into the Statistical Package of Social Sciences (SPSS) software, for analysis. Demographic characteristics of the respondents will be analyzed using descriptive data analysis. The first objective seeks to examine the relationship between borderline depression, severe depression and extreme depression levels and substance use among students in tertiary institutions. A chi-square test will be used to answer this objective. The second objective aims at assessing the institutional structures put in place to detect depression among students of tertiary institutions. Descriptive data analysis will be used to answer this objective. Qualitative data analysis will involve the identification, examination, and interpretation of patterns and themes in textual data to determine how these patterns and themes help to answer the research questions.
