The deficit model (or the deficit perspective) involves the identification and emphasis on an individual's "problems." Within a therapeutic setting, the deficit approach to therapy would involve focusing on how to "fix" the problem the client faces.
Hammond, W. (2010). Principles of strength-based practice[PDF file]. Retreieved from https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=11&cad=rja&uact=8&ved=2ahUKEwi3s8K3nfPgAhWxm-AKHXfpDJAQFjAKegQIDRAC&url=http%3A%2F%2Fwww.ayscbc.org%2FPrinciples%2520of%2520Strength-2.pdf&usg=AOvVaw20903sPDWQc86qqJI92SQJ.