Chapter 17: Psychotherapeutic Drugs – Antidepressants & Antipsychotics

The pathophysiology of these disorders is explored through theories like the biogenic amine hypothesis (BAH), which posits that alterations in concentrations of key neurotransmitters—including dopamine, norepinephrine, and serotonin—are primary causes. Pharmacological treatment is categorized into four main classes: anxiolytic drugs, mood stabilizers, antidepressants, and antipsychotics. Anxiolytics, such as benzodiazepines, primarily function by enhancing the inhibitory effects of GABA in the CNS, though drugs like buspirone offer non-sedating alternatives. Lithium is the traditional mood stabilizer, requiring meticulous serum level monitoring due to its narrow therapeutic index and interaction with sodium and hydration status. Antidepressants are broadly divided into first-generation drugs (TCAs and MAOIs) and preferred second-generation drugs (SSRIs and SNRIs), which work primarily by inhibiting the reuptake of serotonin and norepinephrine. Critical safety concerns with antidepressants include the risk of serotonin syndrome with excessive serotonergic activity and the lethal potential of TCA overdose. Antipsychotic drugs, including conventional (e.g., haloperidol) and newer atypical agents (e.g., clozapine, risperidone), treat psychotic symptoms by blocking dopamine receptors; atypical drugs offer better profiles but still carry risks like extrapyramidal symptoms (EPS), tardive dyskinesia, and the development of cardiometabolic syndrome. The nursing process emphasizes thorough neurological and mental status assessment, continuous monitoring for suicidal ideation, and diligent patient education regarding medication adherence, adverse effects (such as orthostatic hypotension or agranulocytosis risk with clozapine), and the required washout periods between certain drug classes.