本研究探討少年內化與外化症狀併發的機制，提出家庭因素是內外化症狀共同致病因子的假設，並檢視犯罪與一般少年在內外化症狀併發上的差異情形。本研究參與者包括一般及犯罪少年，有效樣本數共計1,905位。以無記名自陳式問卷蒐集資料，問卷內容包括：憂鬱及精神分裂症狀（內化症狀）量表、反社會及攻擊行為（外化症狀）量表、雙親管教、親子關係、親子衝突、雙親精神疾病、家庭氣氛（家庭因素）量表及人口變項。各量表顯示具備可接受的信度與效度。研究結果顯示，在控制家庭因素的影響下，一般少年的內外化症狀關連性降低，不過仍具顯著關連，而犯罪少年的併發程度則顯著降低。此外，犯罪少年內外化症狀併發的情形較一般少年為低，且內外化症狀較一般少年為嚴重。上述結果支持本研究假設。文後就理論及實務上的意涵進行討論，並提出後續研究建議。

The present study investigates the mechanism of co-occurrence of internalizing and externalizing symptoms in Taiwanese juveniles, proposing that family factor is the shared risky factor of internalizing and externalizing symptoms, and the differences of normal and delinquent juveniles in the co-occurrence of internalizing and externalizing symptoms are also examined. Subjects include normal and delinquent juveniles, the effective sample size is 1,905. Anonymous self-report questionnaire is adopted to collect data. Variables measured in the questionnaire involved depressive and schizophrenic symptom (internalizing symptoms), antisocial and aggressive behavior (externalizing symptoms), parental discipline, parent-child relationship, parent-child conflict, parental mental illness, family atmosphere (family factor), and demographic data. The scales in the questionnaire show acceptable reliability and validity. The results of the study indicate that the extent of co-occurrence of internalizing and externalizing symptoms is decreased but still with significance under the control of family factor in the normal juveniles, however the extent of co-occurrence is significantly lowered in the delinquent juveniles. Besides, the degree of co-occurrence of internalizing and externalizing symptoms in delinquent juveniles is lower than normal juveniles, and both internalizing and externalizing symptoms are more severe in delinquent juveniles than normal juveniles. The results above-mentioned indicate that the hypotheses of the study are all supported. The theoretical and practical implications of the study are addressed. Suggestions for future research include: engaging in longitudinal study to testify the impact of family factor, doing experimental research to examine the mechanism of co-occurrence of internalizing and externalizing symptoms, finding out other shared risky factor of internalizing and externalizing symptoms in juveniles, sending for parents and teachers to assess juveniles to cross-validate the data.