[Psychiatric] drugs have so many side effects because using them to treat a complex psychiatric disorder is a bit like trying to change your engine oil by opening a can and pouring it all over the engine block. Some of it will dribble into the right place, but a lot of it will do more harm than good.

Using an automotive metaphor, the speaker argues that many psychiatric medications act too broadly on the brain to be precisely “targeted” to the underlying causes of complex mental disorders. Like dumping oil over an engine rather than routing it into the lubrication system, a drug introduced into the body may produce some desired effects while also affecting many other systems, leading to unwanted side effects. The comparison underscores a critique of reductionist or overly blunt biomedical interventions and implies a need for more selective treatments (or complementary approaches) that better match the complexity of psychiatric conditions.