Other factors that influence treatment adherence are the following: symptoms of the illness, such as hypomanic denial, psychosis, comorbid disorders, personality disorders and substance abuse disorders . Side effects of medications and unfavorable personal attitudes toward treatment can also have a large negative impact on treatment adherence. The effectiveness of psychotherapeutic interventions to improve adherence will address the factors that are changeable and most relevant to treatment adherence in a given individual. These factors will undoubtedly differ depending on the individual's psychiatric symptoms, medication response patterns, age, gender, and cultural context.