Prescription medications are intended to help people, but when combined with other medications, they can prove to be a lethal killer. Heath Ledger, a legendary actor in the making, died this way in 2008. Michael Jackson, a legend of music, may have died the same way.

Input/Output
Most knowledge about how mental health medications truly work has much to do with input and output, but not necessarily what happens in between. Take, for instance, antidepressants. It is known that serotonin and norepinephrine levels help determine someone’s mood. For medications like Cymbalta, they target the receptors of both neurotransmitters to better keep those levels increased in the brain. Yet there is no specified, set amount of increase in either neurotransmitter that will happen when taking Cymbalta, nor is it specifically known HOW those neurotransmitters are made in the first place. The creators just know what happens (an increase of both in the brain) when it is taken and have statistics based on trials and responses from people who take Cymbalta. That is also why doctors rely on patient feedback to determine whether or not your prescriptions should be increased, decreased, etc. If you read the technical information for these medications, they often use the word “indicate” to illustrate their intent, rather than “treat” or “cure”.
Interactions
Since neurotransmitter levels can’t be directly measured, it can make it more dangerous to take certain medications and combine them with other substances. Pay particular attention to the “Interactions” or “Important Safety Information” section of the medication information. Zoloft, for example, should not be taken in conjunction with MAO inhibitors, or MAOIs. MAOIs like Marplan prevent the breakdown of neurotransmitters like serotonin, also increasing their availability. Zoloft is considered an SSRI, or selective serotonin reuptake inhibitor, that helps keep serotonin in the brain. When SSRIs and MAOIs are combined, they can cause serotonin syndrome, which is an overdose of serotonin in the brain. This can lead anywhere from increased heart rate, to twitching, to a heart attack. This can also happen if an SSRI is combined with prescription pain killers such as Demerol. Benzodiazepines used to treat anxiety (like Xanax) could also cause serotonin syndrome. Zoloft, Xanax and Demerol prescriptions were all found in Michael Jackson's residence. Heath Ledger’s toxicology report showed he had several different pain killers in conjunction with anti anxiety medications in his system at the time of death.