The objective of this cross-sectional study was to determine drug related problems (DRPs) of child and adolescent outpatients with mental health problem in 2017. Adverse drug reactions (ADRs) and medication adherence data were interviewed and collected. Thirty-six children are diagnosed with attention deficit hyperactivity disorder (ADHD) and thirty-two adolescents are diagnosed with depression. First-line drug for ADHD treatment is 10 mg. of methylphenidate plain tablet. First-line drug for depression treatment is 20 mg. of fluoxetine tablet. The main DRPs were non-adherence and adverse drug reactions. Forty-one patients reported side effects and adverse drug reactions. Thirty-seven participants were adjusted their attitudes about medication adherence. For ADHD group, most adverse symptoms were appetite decreasing (41.7%) and headache (13.9%). For depression group, most adverse symptoms were appetite changing (34.4%) and drowsiness (28.1%). These adverse effects are categorized to type A ADRs. They are usually a consequence of the drug’s primary pharmacological effect. Misunderstanding for ADRs management can directly lead to non-adherence. There is a greater risk for ADHD children and depressive adolescents about medication use. Pharmacists should prioritize and attach great importance to care givers about medication adherence. The results from this study were applied for drug counseling and pharmaceutical care plan to improve the treatment effectiveness and drug safety in ADHD children and depressive adolescent.

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