This study reports the development of adaptive processes in two groups of adolescents assessed initially and 2 years later with clinical research interviews. Students from a public high school (N = 44) and inpatients on an adolescent psychiatric ward (N = 51) formed the two subject groups. The psychiatrically hospitalized group had significantly improved scores after a 2-year interval on four of six adaptive process Summary Scales: Task Orientation, Relatedness, Self Knowledge, and Inner Synthetic Functions. However, these higher scores did not reach the levels of the high school group at either point of assessment. The scores in the high school group remained stable over time except for an increase in the area of Self Knowledge. The value of this interview-derived assessment, in comparison to other forms of measurement, is discussed, and consideration is given to factors which contribute to the differences between groups.