That carries the implicit conclusion that disordered behaviors are not learned but are spontaneously generated by the disordered brain. According to the medical model, for treatment (such as drugs), to be effective, it should be directed as closely as possible at correcting the theorized chemical imbalance in the brain of the person with mental illness.
The underlying assumption is that disordered behaviors emerge spontaneously due to the brain's internal state, according to the medical model. For effective treatment, such as medication, it must target the theorized chemical imbalance in the person's brain with a mental disorder as closely as possible.