Depression in myotonic muscular dystrophy

Depression was studied in adults with myotonic muscular dystrophy (MMD). The subject groups consisted of 27 MMD patients, an able-bodied control group of 27 adults (CON), a nonprogressively disabled control group of 17 adult paraplegics (SCI), and a progressively disabled neuromuscular disease control group of 11 adults with limb-girdle syndrome (LGS). The study utilized a test battery consisting of the Minnesota Multiphasic Personality Inventory (MMPI), the Institute of Personality and Ability (IPAT) Depression test, the Suicide Probability Scale (SPS), and the California Psychological Inventory (CPI). The MMD group scored significantly higher on the MMPI Depression scale, the IPAT Depression Test, and the SPS Hopelessness subscale, than the CON or SCI groups. Conversely, the MMD group showed lower levels of positive mental health than these two groups on the MMPI Ego Strength and CPI Well-Being scale scores. The MMD group did not differ significantly from the LGS group in any of the five measures. A definite tendency toward depression was evident among MMD patients. A similar tendency was noted in the small LGS group. The progressive and disabling nature of the disease appears to be the major reason for depression in MMD patients. Our data do not support the concept that depression is an intrinsic characteristic of MMD.