Our ancestors without fear, worry and anxiety are not our ancestors, as organisms without defense systems were extinct. Therefore, while behavior such as fear and anxiety are useful to prevent harm, the exaggerated form, that is, anxiety disorders, has more costs than benefits. Likewise, while a panic attack is a normal and useful response in the face of life-threatening danger, a panic disorder results from false alarms in anticipating possible danger. Or simply put: People suffering from anxiety disorders and panic attacks apply ‘successfully’ their genetically enrooted defense system, though, in a context, where the risk of harm is actually very low. We present a succinct introduction to evolutionary psychology and psychiatry, focusing specifically on anxiety disorders and depressive disorders. Mentioning both anxiety and depressive disorders at the same time makes sense, as depression might be considered a response following perceived or actual danger, whereas anxiety concerns threat or impending danger, that is, the anticipatory phase.